An Introduction to Sustainable Aquaculture [1 ed.] 9781003174271

Table of contents :
Cover
Half Title
Title Page
Copyright Page
Table of Contents
List of Contributors
Part I Basic Concepts
1 Introduction
References
2 What Is Aquaculture?
2.1 Introduction: Brief History of Aquaculture
2.2 Introduction to the Biology of Farmed Aquaculture Organisms
2.2.1 The Circulatory System and Its Relationship With the Environment
2.2.2 Reproduction in Aquaculture Organisms
2.2.3 Growth in Aquaculture Organisms
2.2.4 Immune Response
2.3 Types of Aquaculture Production and Management Systems
2.3.1 Depending On the Number of Species Produced
2.3.2 Depending On the Rearing Density
2.3.3 Depending On the Stage to Be Produced
2.3.4 Depending On Hydrology
2.3.5 Depending On the Location of the Facilities
2.3.6 Depending On the Production Objective
2.3.7 Depending On the Seed Origin
2.4 Aquaculture Current Status
2.5 Final Remarks
2.6 Chapter Review Questions
References
3 What Is Sustainability?
3.1 Introduction
3.2 Sustainability Pillars and the Relationship Between Them
3.3 Sustainability Throughout History
3.4 Sustainability, an Elusive Definition
3.5 Types of Sustainability
3.6 Managing Sustainably: the Concept of Governance
3.7 Aquaculture and Sustainability
3.8 Final Remarks
3.9 Chapter Review Questions
References
Part II Aquaculture and the Environment
4 Effects of the Environment On Aquaculture Organisms
4.1 Introduction
4.2 Temperature
4.3 Dissolved Gases
4.3.1 Dissolved Oxygen
4.3.2 Carbon Dioxide (CO2)
4.4 Salinity
4.5 PH
4.6 Dissolved Particles and Compounds
4.6.1 Nitrogen Compounds
4.6.2 Calcium Carbonate
4.7 Light
4.8 Effect of the Presence of Other Organisms
4.9 Suspended Particles
4.10 Meteorological Phenomena
4.11 Final Remarks
4.12 Chapter Review Questions
References
5 Aquaculture’s Effect On the Environment
5.1 Introduction
5.2 Impacts On Water Quality
5.2.1 Organic Particles
5.2.2 Proliferation of Primary Organisms
5.2.3 Inorganic Particles
5.3 Impacts On the Atmosphere
5.3.1 Greenhouse Gas Products of Energy Consumption
5.3.2 Other Greenhouse Gas Emissions Associated With Aquaculture
5.3.3 Estimating Environmental Impacts: a Brief Introduction to Life Cycle Analysis
5.4 Impacts On Land and High-Value Ecosystems
5.5 Impacts On Wildlife
5.5.1 Abundance
5.5.2 Species Richness (Diversity)
5.5.3 Physiological Changes
5.5.4 Pollution (Biological)
5.5.5 Infection Rates
5.5.6 Survival and Fertility
5.6 Potential Ecologically Beneficial Outcomes From Aquaculture
5.6.1 Biological Control
5.6.2 Species Recovery
5.6.3 Habitat Restoration
5.6.4 Habitat Protection
5.6.5 Ex Situ Conservation
5.6.6 Wild Harvest Replacement
5.6.7 Habitat Rehabilitation
5.6.8 Removal of Overabundant Species
5.6.9 Coastal Defence
5.6.10 Bioremediation
5.6.11 Assisted Evolution
5.6.12 Climate Change Mitigation
6.2.1 Crustaceans
6.2.2 Marine Fish
6.2.3 Freshwater Fish
6.2.4 Bivalve Molluscs
6.2.5 Macroalgae
5.7 Final Remarks
5.8 Chapter Review Questions
Notes
References
6 Aquaculture and Climate Change
6.1 Introduction
6.2 Impacts of Climate Change On Aquaculture Production Systems
6.3 Mitigation of the Activity Impacts and Negative Effects of Climate Change
6.3.1 Public Sector Strategies to Mitigate Impacts
6.3.1.1 Production Zoning
6.3.1.2 Production Quotas
6.3.1.3 Taxes, Fines, and Subsidies
6.4 The Mitigation of Impacts From the Private Sector
6.4.1 Use of Clean Technologies
6.4.2 Multitrophic Aquaculture
6.4.3 Optimisation of the Operation of Aquaculture Production Units
6.5 Market Strength as an Incentive to Reduce the Impacts of the Activity
6.5.1 Consumer Power and Eco-Labelling
6.5.2 Establishment of Carbon Markets
6.6 Adaptation Mechanisms to Climate Change
6.7 An Example of the Possible Impacts of Climate Change On Bioeconomic Indicators and Its Application for Decision-Making Under an Uncertain Climate Context
6.8 Final Remarks
6.9 Chapter Review Questions
References
Part III Aquaculture and Economics
7 A Brief Introduction to Economics and Its Relationship With Aquaculture
7.1 Introduction
7.2 Economic Scales
7.3 Supply and Demand
7.4 Macroeconomics
7.5 Microeconomics
7.5.1 The Production Function
7.5.2 The Profit Function
7.6 The Economy and Natural Resource Management
7.6.1 Private Vs. Common Resources
7.6.2 The Concepts of Externalities and Free-Riders
7.7 Some Relevant Economic Schools of Thought
7.7.1 Ecological Economics
7.7.2 Environmental Economics
7.7.3 Circular Economy
7.7.3.1 Relationship Between Production and Consumption
7.8 Economics as a Tool for Sustainable Aquaculture Production
7.8.1 Private Sector Economic Tools
7.8.1.1 Environmental, Social, and Corporate Governance (ESG)
7.8.2 Public Sector Economic Tools
7.8.3 Social Economic Tools
7.8.3.1 The Power of the Consumer
7.9 Final Remarks
7.10 Chapter Review Questions
Notes
References
8 Aquaculture and Fisheries
8.1 Introduction
8.2 Ecological Interactions
8.2.1 Habitat Modification
8.2.2 Aquafeeds Input
8.2.3 Aquaculture Escapements
8.2.4 Exotic Species
8.2.5 Disease Transmission
8.2.6 Enhanced Fisheries and Capture-Based Aquaculture
8.3 Socioeconomic Interactions
8.4 Future Trends for Fisheries and Mariculture
8.5 Final Remarks
8.6 Chapter Review Questions
Notes
References
9 Aquaculture Value Chain Analysis
9.1 Introduction
9.2 Value Chain Analysis Method
9.2.1 Point of Entrance for the Value Chain Analysis
9.2.2 Value Chain Cartography
9.3 Examples of Value Chain Analysis Applications in Aquaculture
9.4 Value Chain and Globalisation
9.5 Final Remarks
9.6 Chapter Review Questions
Notes
References
10 Aquaculture Bioeconomics: A Brief Introduction
10.1 Introduction
10.2 Aquaculture Bioeconomics
10.2.1 Bioeconomic Indicators in Aquaculture Production
10.3 Bioeconomic Model
10.3.1 Biological Sub-Model
10.3.1.1 Growth
10.3.1.2 Natural Mortality
10.3.1.3 Biomass
10.3.2 Technological Sub-Model
10.3.2.1 Feed Consumption Per Individual
10.3.3 Economic Sub-Model
10.3.3.1 Costs and Revenues
10.3.3.2 Profits and Present Value
10.4 Final Remarks
10.5 Chapter Review Questions
Appendix
Constructing an Aquaculture Bioeconomic Model
A.1 Constructing the Biological Sub-Model
A.1.1 Results of the Biological Sub-Model
A.2 Constructing the Technological Sub-Model
A.2.1 Results of the Technological Model
A.3 Economic Sub-Model
A.3.1 Results of the Economic Model
A.4 Applied Examples Using the Aquaculture Bioeconomic Model
Notes
References
11 Aquaculture: Uncertainty Sources and Risk Quantification Techniques
11.1 Introduction
11.2 Risk and Uncertainty in Aquaculture
11.2.1 Uncertainty Sources in Aquaculture
11.2.2 Uncertainty in Environmental Variables
11.2.3 Uncertainty in Operational and Technological Variables
11.2.4 Uncertainty in Biological Behaviour
11.2.5 Uncertainty Associated With the Market and Financial Institutions
11.2.6 Uncertainty Associated With Institutional Aspects
11.2.7 Uncertainty of Undetermined Origin
11.2.8 Uncertainty in Bioeconomic Models for Projection Purposes
11.3 Techniques for Quantifying Risk in Aquaculture
11.3.1 Sensitivity Analysis
11.3.2 Stochastic Models: Monte Carlo Simulation
11.3.3 Scenario Analysis
11.3.4 Bayesian Method
11.4 Risk and Uncertainty Studies in Aquaculture
11.5 New Techniques for Risk Management in Aquaculture: Machine Learning and Artificial Intelligence (AI)
11.5.1 Facing Uncertainty, a Sustainable Perspective
11.6 Final Remarks
11.7 Chapter Review Questions
References
Part IV Aquaculture and Society
12 Aquaculture and Food Security
12.1 Introduction
12.2 Matching Food Security With Human Population Growth
12.2.1 What Is Food Security?
12.2.2 Food Security Status Around the World
12.3 Aquaculture’s Role in Food Security
12.3.1 The Aquatic Food System
12.3.2 Drivers Affecting Aquaculture and Food Security Trends
12.4 Global Aquatic Production Status
12.5 General Contribution of Aquatic Food to Food Security
12.6 Nutritional Value of Fish for Human Health
12.7 Critical Elements for Food Safety in the Aquatic Food System
12.7.1 Utilisation Dimension in Aquatic Food Systems
12.7.1.1 Availability Dimension in Aquatic Food Systems
12.7.1.2 Stability Dimension in Aquatic Food Systems
12.7.1.3 Sustainability Dimension in Aquatic Food Systems
12.8 Final Remarks
12.9 Chapter Review Questions
References
13 Aquaculture and Employment: Impact On Livelihood and Poverty
13.1 Introduction
13.2 Employment and Its Impact On the Sustainability Pillars
13.2.1 Historical Trends in Aquaculture Employment
13.3 Poverty as a Multidimensional Phenomenon
13.3.1 How Poverty and Well-Being Are Measured
13.4 Working Conditions That Promote Sustainable Development
13.5 Final Remarks
13.6 Chapter Review Questions
References
14 Aquaculture and Animal Welfare
14.1 Introduction
14.2 Pain in Aquatic Organisms
14.2.1 The Evolutionary Function of Pain
14.2.2 Animal Neuroanatomy
14.2.3 Evidence of Pain in Fish, Arthropods, and Molluscs
14.3 Animal Welfare Definition
14.4 Measuring Fish Welfare
14.4.1 Welfare Indicators in Aquaculture
14.4.1.1 Non-Invasive Methods
14.4.1.2 Invasive Methods
14.5 Application of Ethical and Welfare Principles to Aquatic Vertebrates and Invertebrates
14.5.1 Fish Welfare
14.5.2 Invertebrate Welfare
14.6 Animal Welfare Legislation Applied to Fish
14.7 Fish Welfare and the Sustainable Developmental Goals
14.8 The Impact of Intensive Farming On Fish Welfare
14.9 Strategies to Improve Welfare in Aquaculture
14.9.1 Potential Industry Approaches to Fish Welfare in Aquaculture
14.10 Welfare Implications for Aquaculture System Designs
14.11 Final Remarks
14.12 Chapter Review Questions
References
Part V Governance and Technologies
15 Governance, Partnerships, and Cooperation
15.1 Introduction
15.2 Governance
15.2.1 What Is Governance and Why Does It Matter?
15.2.2 Private Governance in Aquaculture
15.2.3 Governance Beyond the Aquaculture Farm
15.2.4 Governance for Sustainability
15.3 Partnerships and Cooperation
15.3.1 Defining Partnerships and Cooperation
15.3.2 Types of Partnerships
15.3.3 Partnerships According to Their Scale of Application
15.3.4 Partnerships According to Their Stakeholders
15.3.5 Partnerships and Cooperation in the Aquaculture Context
15.3.6 Private–public Partnerships (PPPs)
15.4 Final Remarks
15.5 Chapter Review Questions
References
16 New Technologies as a Means to Achieve Sustainability
16.1 Introduction
16.2 Digital Technologies in Aquaculture
16.2.1 Automation
16.2.2 IoT and Cloud Computing
16.2.3 Business Intelligence and Big Data
16.2.4 Artificial Intelligence, Machine Learning, and Deep Learning
16.2.5 Geographic Information Systems (GIS) and Remote Sensing
16.3 Breeding and Genetics
16.3.1 Population Genetics
16.3.2 Quantitative Genetics and Selective Breeding
16.3.3 Genome Technologies
16.3.4 Market Genetics and Genetic Bioeconomics
16.3.5 Sex Control
16.3.6 Hologenomics
16.3.7 Epigenetics and Epigenomics
16.4 Systems Technologies and Infrastructure
16.4.1 Infrastructure-Related Technologies
16.4.2 Biotechnologies
16.4.2.1 Pond Or Tank Management
16.4.2.2 Biological Performance Improvement
16.4.2.3 Disease Treatment
16.5 Nutritional Development
16.5.1 Aquafeed: the Use of Fishmeal and Fish Oil
16.5.2 Feed Ingredients
16.6 Management
16.7 Traceability
16.7.1 Why Does Traceability Matter in Aquaculture?
16.7.2 Which Are the Problems and the Existing Solutions When Implementing Traceability?
16.8 Final Remarks
16.9 Chapter Review Questions
Note
References
Part VI Future Expectations
17 Future Directions
17.1 Introduction
17.2 Aquaculture Life Cycle
17.2.1 Stage 1 – Development
17.2.2 Stage 2 – Growth
17.2.3 Stage 3 – Maturation
17.2.4 Stage 4 – Decline
17.3 Aquaculture Opportunity Landscape
17.3.1 Macroeconomic Change
17.3.2 Technological Change
17.3.3 Demographic Change
17.3.4 Psychographic Change
17.3.5 Political and Regulatory Change
17.4 Industry Condition
17.4.1 Knowledge Condition
17.4.2 Demand Conditions
17.5 Final Remarks
17.6 Chapter Review Questions
References
Index

Citation preview

An Introduction to Sustainable Aquaculture

This new textbook provides an accessible introduction to sustainable aquaculture through its relationship with three key pillars: the environment, the economy, and society. As the demand for seafood keeps increasing, aquaculture is considered one of the most promising and sustainable ways to satisfy this demand with nutritious and high-​quality food. It is important to understand, therefore, the wider role and impact aquaculture has on the environment, the economy, and society. The book begins by providing a foundational introduction to aquaculture and sustainability, discussing the complex and interdependent relationship that exists between the two. The core text of the book is divided into four parts which focus on the environment, economics, social impacts, and governance and technologies. Chapters examine key issues surrounding climate change, food security, new technologies, bioeconomics and risk analysis, international cooperation, employment, and animal welfare, with the book concluding with a chapter examining the future directions and challenges for the aquaculture industry. The book draws on global case studies and each chapter is accompanied by recommended reading and chapter review questions to support student learning. This book will serve as an essential guide for students of aquaculture, fisheries management, and sustainable food, as well as practitioners and policymakers engaged in sustainable fishery development. Daniel Peñalosa Martinell serves as Chief Scientific Officer at Shrimpl Pte Ltd., Singapore, and is Visiting Professor in the Interdisciplinary Center for Marine Sciences and Computational Research Center at the National Polytechnic Institute, Mexico. Francisco J. Vergara-​Solana serves as Fisheries Outreach consultant for the Marine Stewardship Council. He is Professor at Baja California Sur Autonomous University, Mexico, and Visiting Professor in the Interdisciplinary Center for Marine Sciences and Computational Research Center at the National Polytechnic Institute, Mexico.

Marcelo E. Araneda Padilla is Manager of the Bioeconomy and Control Unit at Benchmark Genetics, Chile, and Visiting Professor in the Interdisciplinary Center for Marine Sciences and Computational Research Center at the National Polytechnic Institute, Mexico. Fernando Aranceta Garza is Researcher for Mexico at the National Council of Humanities, Sciences and Technologies, and the Fisheries Ecology Program in Northwest Biological Research Center, Baja California Sur, working on fisheries and aquaculture issues for federal, public, academic, and civil organizations.

An Introduction to Sustainable Aquaculture Edited by Daniel Peñalosa Martinell, Francisco J. Vergara-​Solana, Marcelo E. Araneda Padilla, and Fernando Aranceta Garza

Designed cover image: © Getty Images First published 2024 by Routledge 4 Park Square, Milton Park, Abingdon, Oxon OX14 4RN and by Routledge 605 Third Avenue, New York, NY 10158 Routledge is an imprint of the Taylor & Francis Group, an informa business © 2024 selection and editorial matter, Daniel Peñalosa Martinell, Francisco J. Vergara-Solana, Marcelo E. Araneda Padilla, and Fernando Aranceta Garza; individual chapters, the contributors The right of Daniel Peñalosa Martinell, Francisco J. Vergara-Solana, Marcelo E. Araneda Padilla and Fernando Aranceta Garza to be identified as the authors of the editorial material, and of the authors for their individual chapters, has been asserted in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988. All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. Trademark notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. British Library Cataloguing-​in-​Publication Data A catalogue record for this book is available from the British Library ISBN: 978-​1-​032-​00467-​9 (hbk) ISBN: 978-​1-​032-​00461-​7 (pbk) ISBN: 978-​1-​003-​17427-​1 (ebk) DOI: 10.4324/​9781003174271 Typeset in Times New Roman by Newgen Publishing UK

Contents

List of contributors PART I

viii

Basic concepts

1

1 Introduction

3

D A N I E L P E Ñ A L OS A MART I NE L L

2 What is aquaculture?

8

D A N I E L P E Ñ A L OS A MART I NE L L

3 What is sustainability?

24

D A N I E L P E Ñ A L OS A MART I NE L L

PART II

Aquaculture and the environment

37

4 Effects of the environment on aquaculture organisms

39

D A N I E L P E Ñ A L OS A MART I NE L L

5 Aquaculture’s effect on the environment

53

D A N I E L P E Ñ A L OS A MART I NE L L C A S E S T U D Y: JE AN PAUL L HORE NT E CAUS S ADE

6 Aquaculture and climate change F R A N C I S C O J . VE RGARA- ​S OL ANA, F E RNANDO A R A N C ETA G A R ZA , A N D D A N I E L PE ÑAL OS A MART I NE L L C A S E S T U D Y: JOS É AGUI L AR MANJARRE Z

71

vi  Contents PART III

Aquaculture and economics

91

7 A brief introduction to economics and its relationship with aquaculture

93

D A N I E L P E Ñ A L OS A MART I NE L L C A S E S T U D Y: F E RNANDO GONZ AL E Z L AXE

8 Aquaculture and fisheries

115

F E R N A N D O A RANCE TA GARZ A C A S E S T U D Y: US S I F RAS HI D S UMAI L A

9 Aquaculture value chain analysis

132

D A N I E L P E Ñ A L OS A MART I NE L L

10 Aquaculture bioeconomics: a brief introduction

145

F E R N A N D O A RANCE TA GARZ A C A S E S T U D Y: HUMBE RTO VI L L ARRE AL COL MEN A RES

11 Aquaculture: uncertainty sources and risk quantification techniques

175

M A R C E L O E . A RANE DA PADI L L A AND D A N I E L P E Ñ A L OS A MART I NE L L

PART IV

Aquaculture and society

197

12 Aquaculture and food security

199

F E R N A N D O A RANCE TA GARZ A

13 Aquaculture and employment: impact on livelihood and poverty 225 F R A N C I S C O J . VE RGARA- ​S OL ANA

14 Aquaculture and animal welfare F E R N A N D O A RANCE TA GARZ A

240

Contents  vii PART V

Governance and technologies

263

15 Governance, partnerships, and cooperation

265

F R A N C I S C O J . VE RGARA- ​S OL ANA AND D A N I E L P E Ñ A L OS A MART I NE L L C A S E S T U D Y: AL E JANDRO F L ORE S - ​N AVA

16 New technologies as a means to achieve sustainability

286

D A N I E L P E Ñ A L OS A MART I NE L L C A S E S T U D Y: CI ARON MCKI NL E Y

PART VI

Future expectations

315

17 Future directions

317

F R A N C I S C O J . VE RGARA- ​S OL ANA C A S E S T U D Y: MARCE L O E . ARANE DA PADI L L A

Index

337

newgenprepdf

Contributors

José Aguilar Manjarrez Aquaculture officer for Latin America and the Caribbean Regional Office FAO, Panama Alejandro Flores-​Nava Chief Fisheries and Aquaculture Officer for Latin America and the Caribbean FAO, Panama Fernando Gonzalez Laxe Professor of Applied Economics Universidade Da Coruña, Spain Jean Paul Lhorente Caussade Technical and breeding manager Benchmark Genetics Chile, Chile Ciaron McKinley CEO Shrimpl Pte Ltd. Singapore Usiff Rashid Sumaila University Killiam Professor of Oceans & Fisheries Economics and Canada Research Chair (Tier 1) The University of British Columbia, Canada Humberto Villarreal Colmenares Professor & President of the World Aquaculture Society Centro de Investigaciones Biológicas del Norte, Mexico

Part I

Basic concepts



1 Introduction Daniel Peñalosa Martinell

Human development has been significantly marked by the domestication of plants and animals for the species’ advantage. Both agriculture and livestock production have been practised for millennia and are considered foundations for the development of civilisations. Today, the activity responsible for the controlled production of living organisms with an aquatic origin is known as aquaculture. Although the domestication of some aquatic organisms has been around for hundreds of years, humanity has depended mostly on the fishery industry to support its demand for seafood and other inputs from an aquatic origin. It was not until recently that aquaculture became a significant source of food (representing around 50% of the fish and shellfish destined for human consumption) and an important component of some regional economies. Despite the vast range of aquaculture species potential and the currently large number of organisms produced, this book mainly focuses on the production of fish and shellfish unless stated otherwise. This decision was made to focus the ideas in the text and to avoid overreaching the book’s extent. Nonetheless, information on other types of aquaculture is included on occasion and in some of our recommended readings. Unlike any other animal-​ origin industry, aquaculture confronts unique challenges. Many factors need to be considered, such as interactions between the different environments (land, water, air), the influence of each environment on the animals produced, the difficulty of manipulating organisms, and the extensive variety of reared species of different groups, families, phyla, and even kingdoms. In addition, an increase in complexity exists as a result of human interventions and decisions, such as rearing densities, infrastructure and production systems, food and animal handling, and so on. During the beginning of the so-​called “Blue Revolution”, which in this context refers to the significant growth of aquaculture over the last forty years,1 the large profit margins obtained from farmed species allowed management based on trial and error. The increase in competition –​especially that observed in certain species, such as tilapia, shrimp, or salmon –​ has significantly reduced DOI: 10.4324/9781003174271-2

4  Daniel Peñalosa Martinell profit margins, making it necessary to increase knowledge, management, and production control, besides understanding the different effects that management decisions can cause without creating a risk to production. At the same time, the production processes have to be optimised to maximise profit margins that were previously impossible. In addition to the challenges observed in the private administration of aquaculture businesses, a crisis regarding the rules and regulations of these activities has been observed. The novelty of the production systems and their continuous evolution, as well as the difficulty in defining responsibilities in terms of regulation, has prevented the application of public policies to mitigate negative production impacts. For example, should administration or regulation be conferred to the agencies in charge of fisheries and agriculture, or to those in charge of coastal management or natural resources, or is it necessary to create a new agency or secretariat? Usually, the lack of such regulation comes from a lack of understanding of the activity’s impact, leading to complex management and administration. During the years when production started to grow significantly, certain actions were carried out by regulators and other stakeholders to promote aquaculture. Although these actions significantly boosted production growth, they also had important negative environmental and social effects, however at the time of their implementation, such impacts were unknown or underestimated. The destruction of high ecological interest areas, such as mangroves, for their transformation into cultivation areas; indiscriminate use of antibiotics and fertilisers; eutrophication of soils and abandonment of facilities; introduction of invasive species; reduction of genetic variety; abuse of fishmeal and fish oil consumption from fishing; and contamination of aquifers are some of the negative impacts associated with aquaculture production during the first years of industrialisation. Following the negative environmental impacts generated by unsustainable practices –​coupled with the growing food demand and uncertain global climate context –​policies have focused on promoting the development of sustainable activities, including the aquaculture and fishing sectors. A reflection of this trend can be seen in Goal 14 of the Sustainable Development Goals (SDGs) established by the United Nations (UN), referring to the sustainability of oceans, seas, and aquatic resources, as well as in the UN initiative to designate the 2021–​2030 decade as the ocean science decade. However, there remains a long way to go regarding the estimation of aquaculture impact and the development of tools and measures aimed at maximising the beneficial aspects and minimising negative externalities. While aquaculture has gained a bad name due to its environmental impacts, especially during the beginning of its industrialisation,2,3 it is important to highlight that these effects have been highly dependent on the methods used for production. Moreover, a wide variety of benefits associated with the activity have been obtained. From an environmental point of view, the pressure on fisheries has been significantly reduced, enabling the supply of quality animal protein food to a growing global population. In addition, there is significant potential to perform

Introduction  5 aquaculture that encourages genetic diversity and even systems that promote restocking in areas where natural populations have declined. Moreover, aquaculture represents a source of income for about 10% of the global population (directly or indirectly) with more than 19.3 million people whose employment is directly related to this activity.4 Aquaculture production has reduced the prices of certain seafood products, making them accessible to a portion of the population that could not previously afford this luxury, improving accessibility to high-​quality protein, and having a positive impact on food security.5,6 Seafood consumption is the highest in the world among animal products, averaging more than 20 kg per capita per year,7 almost 5 kg more than poultry, and more than double that of beef.8 In addition, this consumption is expected to grow at around 5% annually over the next decade. From an economic point of view, aquaculture generates more than USD 280 billion a year directly.4 In addition, marine products are amongst the most widely traded foods in the world, creating over USD 150 billion in trade in 2020 (both fishing and aquaculture).4 The two products that dominate the international market in terms of value are salmon and farmed crustaceans, while the volume is dominated by white fish, such as tilapia and carp.4 As mentioned above, this novel industry has experienced not only a wide variety of challenges but also opportunities. Aquaculture regulation has increased exponentially over the last 40 years, which coupled with intensive activity from the research and development groups worldwide has led to a host of ingenious and interesting management systems being developed. This situation has maximised production yield while the negative impact of the activity is minimised, such as recirculation systems, aquaponics, or zero discharge systems. Throughout this book, the concept of sustainable aquaculture is introduced. The book is divided into six parts or blocks, which in turn are composed of a series of chapters. The chapter structure is as follows. First, a summary of the chapter contents and structure is included, subsequently followed by the chapter content. Then, a part of each chapter is designed to reinforce learning, which is included as questions and case studies. Finally, recommended readings for studying the subject in depth are also included to supplement the material presented throughout the book. The first part of the book describes the concept of aquaculture with the purpose of providing the reader with the necessary bases to understand the biology of the organisms, the need for this knowledge, production methods that exist, and different management techniques. In the same way, this part deals with the concept of sustainability, the different types and history of this concept, and the importance it has in the aquaculture industry. Finally, the functional definition of sustainable aquaculture is introduced and used throughout the book. The second block discusses the relationship between aquaculture and the environment while addressing different questions, such as: How does aquaculture production impact the environment? How do environmental changes affect aquaculture production? What is the expected impact of climate change on aquaculture production? Will production continue in the same way?

6  Daniel Peñalosa Martinell The third block deals with the relationship between aquaculture and the economy. On the one hand, macroeconomic production aspects are introduced along with other economic principles, emphasising the current state of the industry, trade, production chains, activity value, and future expectations. On the other hand, microeconomic aspects are discussed, which are usually responsible for the decisions made by each producer and associated with a significant impact on global environmental and economic performance. This section deals with measurement, control, and management tools that allow the producers, scientists, and decision-​makers to evaluate the impacts of aquaculture production, measure its risks, and make value propositions to improve practices. The fourth block of the book focuses on the social impacts derived from aquaculture activity. Important factors are discussed, such as equality, food security, well-​being, poverty, aquaculture from a gender equality perspective, and ethical production aspects in the different components of the production chain from obtaining seed to marketing, including aspects of fair trade, animal welfare, and sustainable production. The fifth block of the book is divided into two chapters necessary to achieve sustainable aquaculture: governance and new technologies. The governance chapter deals with various topics, such as production control through the application of economic tools –​such as taxes and subsidies –​and the importance of developing alliances and cooperation at different scales with an emphasis on the international organisations that exist and sustainable production needs. The second chapter introduces and discusses the new existing technologies for sustainable aquaculture as well as their obstacles to becoming a future reality. The sixth block is composed of the future expectations of the industry. Since innovation in aquaculture is also driven by the sector’s maturation and opportunities that arise from changes in society (such as new regulations, shifts in consumption patterns, increased environmental awareness, and advancements in technology), we deal with future directions of the industry as a whole in the final chapter of the book. The topics covered in this book are extremely extensive and complex, and require great depth of knowledge to be fully understood. Thus, the intention of this book is not to contain all the information on all the topics covered but rather to serve as an introduction and guide that allows the study of each topic to continue. For this reason, a bibliography considered essential, relevant, and of great interest is included in each of the topics covered, so that readers can delve into those chapters that are useful to them. In that spirit, this book can be read from cover to cover or separately by topic, depending on the interest of the reader. The authors expect that, by the end of this book, the reader will have a clear, robust, and scientifically based idea about the current state and challenges of aquaculture. Furthermore, the cases introduced, exercises provided, and theory described should hopefully be of value to future researchers, producers, and decision-​makers, which may serve as a motivational tool for those actors responsible for guiding the future industry towards sustainable aquaculture production.

Introduction  7 References 1 Garlock, T., et al. “A global blue revolution: Aquaculture growth across regions, species, and countries.” Reviews in Fisheries Science & Aquaculture 28.1 (2020): 107–​116. 2 Chen, W., and S. Gao. “Current status of industrialized aquaculture in China: A review.” Environmental Science and Pollution Research 30.12 (2023): 32278–​32287. 3 Asche, F., K. H. Roll, and R. Tveteras. “Economic inefficiency and environmental impact: An application to aquaculture production.” Journal of Environmental Economics and Management 58.1 (2009): 93–​105. 4 FAO. 2022. The State of World Fisheries and Aquaculture 2022. Towards Blue Transformation. Rome, FAO.https://​doi.org/​10.4060/​cc046​1en 5 Anderson, J. L. “Market interactions between aquaculture and the common-​property commercial fishery.” Marine Resource Economics 2.1 (1985): 1–​24. 6 Asche, F., et al. “Aquaculture: Externalities and policy options.” Review of Environmental Economics and Policy 16.2 (2022): 282–​305. 7 Stentiford, G. D., and Holt, C. C. “Global adoption of aquaculture to supply seafood.” Environmental Research Letters 17.4 (2022): 041003. 8 Whitton, C., Bogueva, D., Marinova, D., and Phillips, C. J. “Are we approaching peak meat consumption? Analysis of meat consumption from 2000 to 2019 in 35 countries and its relationship to gross domestic product.” Animals 11.12 (2021): 3466.

2 What is aquaculture? Daniel Peñalosa Martinell

Aquaculture, understood as the activity of producing aquatic organisms and their derivatives, is one of the fastest-​growing food production industries in the world. Most of this growth occurred during the decades of the 1980s, 1990s, and 2000s and came with a cost, mainly environmental. Despite this, if the demand for seafood is to be satisfied, aquaculture production must continue to rise, but this growth needs to account for the three pillars of sustainability –​the economy, society, and the environment. To better understand how aquaculture is carried out, its challenges, and opportunities, it is essential to first understand the immense variety of organisms produced, their differences, and needs. This will provide insights into how these organisms can be reared and what can be done to improve the current status of production. 2.1  Introduction: Brief history of aquaculture Domestication is a process by which one or more species from the natural environment are adapted and selected to fulfil a specific role within society. Domestication is a resource developed by our human ancestors with the aim of reducing the existing dependence on the organisms of the natural environment to provide food. Remains and prehistoric studies have led to the belief that more than 10,000 years ago, Homo neanderthalesis and Homo sapiens developed tools for growing plants, as populations began to decline, and food was scarce due to the pressure suffered by megafauna. As on land, pressure on natural fish populations –​ in part due to increased fishing –​ resulted in a reduction in their availability. This situation led ancient humans to develop some systems that allowed for providing these resources at any time without depending on the uncertainty of artisanal fishing. This newly developed activity is known today as aquaculture, which consists of the activities associated with the production of aquatic organisms and/​or products derived from them. According to a group of anthropologists led by Tsuneo Nakajima,1 the first evidence of aquaculture was observed in Jiahu, China. Anthropological evidence was observed in the control of dams and water to maintain and rear one of the most DOI: 10.4324/9781003174271-3

What is aquaculture?  9 produced species in the world today –​the common carp, Cyprinus carpio –​around 6000 BC. In addition to that observed in China, evidence has been found of some type of eel aquaculture performed by Australian Aborigines at around 4500 BC. Evidence points to the use of natural formations as systems to keep eels previously caught with woven baskets, so they were available for their consumption throughout the year. In Europe, besides fish, the Romans were already responsible for the production of other organisms, such as oyster farming in small rectangular ponds, which were of major interest around 100 BC. Despite the fact that dikes and ponds were manipulated to maintain a fish population for human consumption, the techniques used were rudimentary, artisanal and based on little scientific knowledge. The organisms were captured from their natural environment and kept for rearing, without actually closing the aquaculture production cycle, consisting of maintaining breeders, obtaining larvae and fattening, which is discussed later. It was not until some point between the 12th and 14th centuries AD that records of controlled and complete carp production existed, originally developed by the Roman Empire on the banks of the Danube River. The move towards controlled production is believed to have been due to an increase in demand primarily in abstinence periods, when Christians did not consume red meat. The earliest available text on fish production, tank structure, juvenile management, and other typical aquaculture concepts –​ written around 475 BC (although the precise date is unknown) –​is attributed to the Chinese historian and politician Fan Lee (also known as Fan Li or Fau Lai)2 in his monograph entitled “Treatise on Fish Breeding”.2 Another milestone in aquaculture production corresponds to the rearing of marine organisms. The first signs of marine fish production have been found in Hawaii with the evidence of a pond used to host ocean fish around 1000 years ago. Marine organisms, such as Atlantic salmon or Pacific white shrimp, represent a large part of the value generated by aquaculture activities and are among the main drivers of knowledge generation and technology development.3 Finally, the most significant advancement in aquaculture has been the domestication of different species, understanding domestication as the capacity of reproducing organisms in captivity over generations. This advance also led to the creation of genetic improvement programmes and increased productivity associated with a steady seed supply.3 At a global level, approximately at the beginning of the 1970s, the Blue Revolution, known for the enormous growth coming from the aquaculture industry grew 18.8% per year from 1975 to 1985.4 For that same period, agriculture and fishing growth were 2.4% and 1.1%, respectively. Nowadays, aquaculture goes from a semi-​industrial state with small-​scale production to an industry of enormous production with continuous growth of from 5% to 10% per year between the 1980s and the 2000s,5 growth which is higher than that of the rest of the food-​producing industries. As a result of this growth, the complexity of managing aquaculture production has increased and farm administration has become more complicated.

10  Daniel Peñalosa Martinell Currently, the aquaculture industry is a global and complex network of stakeholders with different levels of influence in which aquaculture producers themselves, consumers and regulators participate. However, less obvious participants are also part of this network, such as other food-​producing industries, international markets, interest groups, non-​governmental and international organisations, and other satellite industries in charge of the production of supplies, infrastructure, and research. These actors in turn significantly influence all spheres of sustainability, namely the economy, the environment and society.6 Today, the aquaculture industry is made up of producers of different sizes with different management and production techniques, and a great variety of species produced in different climates and under different circumstances. Furthermore, globalisation has made aquaculture an industry with different production scales where food for the organisms can be produced in Asia, used in America and the final product taken for sale in Europe, or produced and sold at a regional level but with a high degree of interconnection throughout the entire value chain. Thus, given the complexity of these relationships, several concepts are necessary to understand the reason for current aquaculture production to be able to perceive what can be done to change this paradigm. Among the concepts directly associated with production are the biology of the organisms produced (including concepts such as their ethology, immunology, physiology and genetics), production methods and management. 2.2  Introduction to the biology of farmed aquaculture organisms As mentioned at the beginning of this chapter, aquaculture encompasses a wide universe of different species, climates and ecosystems, of which the main groups produced are finfish, bivalve molluscs, crustaceans and algae (Figure 2.1). However, aquaculture also includes –​although to a lesser extent –​the production of other aquatic organisms, such as some echinoderms (e.g., sea urchins), cnidarians (e.g., corals), reptiles (e.g., crocodiles) and amphibians (e.g., frogs). Since the first four groups mentioned are responsible for more than 95% of global aquaculture production,5 they are dealt with throughout the book with an emphasis on animal production. Although a great variety of species, genera and even phyla and kingdoms are found in aquaculture production, there are certain common characteristics for the different farmed organisms in terms of their relationship with the culture medium, reproductive system, response to pathogens and growth. Next, the biological generalities of aquaculture organisms are introduced differentiating three large groups: algae (both macro-​ and microalgae), invertebrate animals (bivalve molluscs and crustaceans) and vertebrate animals (mainly finfish). 2.2.1  The circulatory system and its relationship with the environment

All aquatic animals –​with the exception of mammals and seabirds –​are ectothermic, and poikilotherms that is, their body temperature is the same as that of

What is aquaculture?  11

Figure 2.1 Most important groups of species produced by aquaculture. The size of the sphere represents the number of species in each group. Numbers represent global production in thousand metric tonnes, annual average growth rate and number of species per group.

the environment in which they are found and lack the mechanisms to regulate their body temperature. Some organisms, such as tuna. which means they cannot fully regulate their body temperature, have certain mechanisms of circulation and vasoconstriction that allow –​to a certain extent –​maintaining heat in localised parts of the body. This characteristic is of great relevance since it makes water temperature one of the most determining factors when evaluating the site for growth suitability or a species for a certain climate, as we will see in Chapter 4. Regarding the circulatory system, invertebrate organisms generally have open systems where blood (or haemolymph) is not found in blood vessels but rather directly irrigated to the tissues.7 In these cases, haemolymph usually accumulates in lacunae or sinuses. In most of the cases that concern us, the circulatory system is associated with gas exchange, but unlike terrestrial vertebrates, not all animals use haemoglobin as a respiratory pigment. The protein used for oxygen transport, as well as the element that functions as an active centre, determines some of the nutritional requirements of farmed animals. For example, in the case of cephalopods and crustaceans, the protein responsible for transporting oxygen is known as haemocyanin which has copper, unlike haemoglobin (used by fish and bivalves), which has iron in its active centre.8 On the other hand, vertebrate animals, such as finfish, have closed circulatory systems; their blood is transported by blood vessels from the heart to the gills

12  Daniel Peñalosa Martinell where gas exchange takes place, and from there to the tissues and back to the heart in a single circuit that runs through the entire body.9 Finally, macroalgae do not have a circulatory system. The gaseous exchange of these organisms occurs through cellular respiration and photosynthesis. 2.2.2  Reproduction in aquaculture organisms

The vast majority of farmed organisms have sexual reproduction, are oviparous, and in most cases, externally fertilised.9 Two significant characteristics for the selection of species suitable for aquaculture are linked to sex. The first is its reproductive potential; most of the reared organisms favour the production of a large number of offspring, for example, a female white shrimp (Litopenaeus vannamei) can lay from 300,000 to 400,000 eggs per female with a low survival in the natural environment, mainly in the early stages of its life (larval stages).10 The intervention of man increases the chances of survival of the offspring. Crustaceans, bivalve molluscs and some finfish all go through certain larval stages. The second desirable characteristic of an aquaculture species corresponds to meat-​producing aquaculture species and is that it reaches commercial size before reaching sexual maturity. In this way, the farmed organisms use their energy for growth and not for sexual maturity, increasing the yield of the food provided. This last point is valid for the cases in which the part of the animal consumed is the muscle, which is the case of most finfish and shellfish; although in some cases, the edible part of the animal is the gonad or some part or component of the reproductive system (for example, in the production of caviar). In those cases, sexual maturity is desirable for the reared organisms. An important exception is the case of macroalgae because all have both sexual and asexual reproduction, as well as a great variety of diversity in their life cycles. In general, sexual reproduction is characterised by having two phases, gametophyte –​ emits haploid gametes through a process of mitosis –​and sporophyte –​emits haploid spores through a process of meiosis. The dominant phase of the cycle is known as the vegetative phase and the algae are considered to be in their adult stage.11 In general, the life cycles of algae can be of three different types: (1) haplontic –​ the vegetative phase is haploid; (2) diplontic –​ the vegetative phase is diploid; and (3) haplodiplontic –​the gametophyte is haploid, produces haploid gametes by mitosis, and the sporophyte is diploid and produces haploid spores by meiosis. In this last type of cycle, the vegetative phase undergoes alternation of generations or metagenesis. As for asexual reproduction (or multiplication), the most common, both in macroalgae and in some animals that have it, is fragmentation. The low specialisation of its cells allows the generation of a new organism from a fragment of the original organisms, giving rise to two genetically identical individuals. 2.2.3  Growth in aquaculture organisms

Growth in the different groups described is very varied, and in most cases, depends on different factors, both endogenous, such as endocrine and genetic, as well as

What is aquaculture?  13 exogenous, such as nutritional and the characteristics of the environment. One of the characteristics that all organisms have is the use of energy for growth until sexual maturity is reached; at this point, energy consumed derives to the creation of progeny. For this reason, one of the characteristics that most species suitable for aquaculture production should show is that it reaches a commercial size prior to sexual maturity (except for the above-​mentioned cases where the gonad is the commercialised product, such as some bivalves, sea urchins, or when enough profit margin justifies a slower growth). Regarding endocrine factors, in the case of fish, the most relevant is the growth hormone, although other compounds are relevant, such as somatomedins and their receptors and IGF-​binding proteins.12 For crustaceans, growth is a discontinuous process and is directly linked to the shedding of the chitin exoskeleton or ecdysis. The moulting process is regulated by various hormones; the moulting hormone or ecdysone is the main moulting promoter, while the moulting inhibiting hormone is the counterpart that adjusts the process. These hormones are emitted by the X organ located in the ocular peduncle of crustaceans. During moulting, organisms absorb water to increase their body mass when the incipient exoskeleton remains elastic; after hardening, absorbed water is lost and new tissues are generated.13 The case of bivalves is particular to each species because they generally use different proteins, as well as calcium carbonate from the medium, to increase the size of their valves, starting around the umbo and increasing towards the outside. Although genetics is known to have a significant effect on the growth capacities of different species, it is a new and constantly developing line of research. Different genes and interactions exist between them and the environment that impacts the performance of a species in captivity. However, the effect of genetics on growth is made evident through artificial selection where the producer selects the organisms that have the best traits to reproduce them and thus obtain offspring with similar characteristics. Thus, in the most important species, making lines or genetic lines that have different performances under different production characteristics has been possible. This possibility helps to maximise the production yield and can have other important benefits, such as sterility of the organisms in culture, increased resistance to diseases or greater production of offspring. However, the negative effects of selection should be taken into account, such as diversity loss or genetic contamination of wild populations derived from their escape.14 One of the most powerful exogenous factors on organism growth is the rearing medium, of which two types are found –​determining and limiting factors. Determining factors are those that directly affect the organism’s growth, increasing or decreasing it, such as temperature, photoperiod or salinity; limiting factors are those for which an optimal threshold exists, such as pH or a tolerance margin, such as oxygen availability or NH4 concentration in water. Finally, nutrition is an exogenous element that determines the growth of the organisms produced. Each species –​ even within the same groups –​ has nutritional peculiarities that they must satisfy to reach their optimal growth potential or, in extreme cases, survive. The nutritional requirements are divided into macronutrients –​ those that supply most of the body’s metabolic energy and

14  Daniel Peñalosa Martinell micronutrients –​those essential nutrients that are needed in small doses, such as minerals and vitamins. Food is such an important factor that it can sometimes account for more than 50% of production costs. Within the groups discussed, four categories are found depending on the food provided. The first three are heterotrophic, that is, they require external food sources for their nutrition, and the last one is that of autotrophic organisms, in other words, they are capable of producing their own food from basic components, using mainly nitrogen and phosphorus as macronutrients. Heterotrophic organisms can be classified into three groups. First, carnivorous organisms feed mainly on other animals in the environment, so they require high concentrations of animal protein in their diet; some examples are sea bass, salmon, sea bream, marine shrimp and lobster. Second, herbivorous species, such as tilapia and carp, do not require animal components to supplement their diet and feed mainly on algae and debris. Third, the group of filter feeders, mainly composed of bivalve molluscs, uses specific appendages to filter microorganisms from water (mostly microalgae) for their food. Finally, autotrophic organisms correspond to algae that produce their energy through the photosynthesis process. 2.2.4  Immune response

Regarding the immune system, two types of response to the presence of a pathogen have been observed: innate and acquired. The innate immune response consists of a set of specialised cells responsible for detecting and eliminating possible pathogenic organisms that are detected within the body. In this case, cells and the rest of the system components lack specificity and memory, that is, they do not differentiate between pathogens and only recognise and eliminate entities foreign to their own systems. The cells that make up this response are generally embedded within the circulatory system, facilitating their movement and increasing their effectiveness. The other type of immune response –​the acquired response –​is unique to vertebrate organisms. This type of response is composed of a system of organs or ganglia that contain cells and other specialised cellular components capable of recognising certain pathogenic components (specific epitopes) and thus provide the ability to respond more quickly and effectively to known pathogens. It is this response that enables the existence and development of vaccines. Despite the aforementioned coincidences among the majority of aquaculture production organisms (with the exception of algae), a series of characteristics differentiate each group and even each farmed species, such as their nutritional requirements, feeding system and behaviour and certain physiological ones (such as osmoregulation, moulting regulation in crustaceans or shell development in bivalves) and reproductive characteristics. Since this book is not, nor is it intended to be, a manual of the biology of each organism, some of the main representative characteristics of each of the most important animal groups in aquaculture production are described. However, if readers wish to delve into any of the particular

What is aquaculture?  15 aspects described for specific species, they can consult the references provided at the end of the chapter. 2.3  Types of aquaculture production and management systems As mentioned at the beginning of this chapter, in addition to the biology of the organisms, another characteristic that determines the impact of aquaculture production on sustainability is the type of production or management system. Because of the great variety of cultivated species, a great number of management systems can be adapted to the characteristics of the different species, climates, cultures and economies. These systems can be classified differently depending on the characteristic used for their classification. Thus, different systems are found depending on the number of farmed species, seeding density used, stage to be produced, hydrology, location of the facilities, origin of the seed and, finally, the production objective. 2.3.1  Depending on the number of species produced

One of the main characteristics of the first aquaculture crop was the use of the flooded wetlands used to produce rice in Asia in combination with carp rearing. On the one hand, carp fed on organisms, such as insects and possible pests for rice, and on the other hand, they provided fertiliser in the form of waste with a high nitrogen content. These systems, where more than one species is produced at the same time, are known as polycultures, while those whose objective is only the production of one species are known as monocultures. In aquaculture, most industrial productions correspond to monocultures, such as shrimp in Asia and Latin America or salmon in Norway and Chile. Nevertheless, the most widely cultivated species in terms of volume worldwide (common carp) comes from a polyculture, generally in combination with rice crops. In recent years, attempts have been made to promote the establishment of polycultures since they are considered to have a lower environmental impact and can be equally profitable. However, nowadays certain monocultures have not become polycultures due to lower productive yields, difficulty in promoting and handling different types of products and exploitation, and a highly demanding qualified labour force, which increases labour costs, among others. A special case of polycultures is the Integrated Multitrophic System (IMS), which is described in more detail in later chapters. 2.3.2  Depending on the rearing density

Density is one of the most determining factors when it comes to obtaining positive economic returns. The more individuals are put into a system, the more biomass may be harvested, which is true up to certain limits and depending on the farmed species, this limit is known as the carrying capacity. On the one hand, a phenomenon known as density dependence exists. Denso-​dependent species have different

16  Daniel Peñalosa Martinell capacities to grow depending on the available space (or density); thus, the higher the density is, the smaller the maximum size of each individual, so a balance must be found between the number of individuals planted and the harvest objective for this type of species. Furthermore, the higher the density of the crop is, the greater the water quality deterioration, which can cause significant problems during rearing. This situation favours disease appearance due to immune system depression, reduces dissolved oxygen concentration –​vital for living organisms –​or increases toxic substances associated with organic waste, such as ammonia and nitrites. In other words, the higher the density is, the greater the control required of the crops and the higher the risk that problems appear. Crops can be classified as extensive if their density is very low (the value of this density depends on the species being reared) and intensive if their density is high. There are ranges between these two systems; for example, medium densities can be considered a semi-​intensive crop and very high densities could be a super-​or hyper-​intensive system. In addition to the main selection characteristic of these systems, crop density has other differentiators between them. Usually, extensive systems do not require adding food since density is very low, so they rely on the ability of the system to provide food in the form of insects and annelids for carnivorous organisms, e.g. shrimp, and in the form of algae and other plants for herbivorous organisms, e.g. tilapia or carp. On the other hand, intensive systems require continuous feeding, normally in the form of pellets, which allows organisms to grow in the face of low food availability for high densities. Hence, as mentioned before, another factor that differentiates intensive and extensive systems is control; the higher the production intensity, the more control is necessary for successful production. 2.3.3  Depending on the stage to be produced

As discussed in the previous section of this chapter, most aquaculture species have different development or larval stages, that is, they have an indirect development. Formerly (and still in some cases today) the common practice of aquaculture consisted of collecting larvae from the natural environment, later taking them to a semi-​controlled system where these larvae would reach commercial sizes. However, this practice has various limitations and negative effects on the environment. In the first place, larval collection from the natural environment is limited to the production capacity of the environment itself, so there is no control over the number of seeds obtained for each productive cycle. Second, removing larvae from the environment nullifies future recruitment of breeding individuals, which limits access to larvae in the future, reducing industry growth and endangering the target species, even with the potential for extinction. Third, the capture of individuals from the environment results in obtaining heterogeneous larvae, which makes management difficult on the farm, limiting the possibilities of intensifying production.

What is aquaculture?  17 Finally, a wide possibility exists of introducing pathogenic organisms from the natural environment due to the null control of reproduction standards, which could lead to production mortality and a significant economic, biological and food source loss for society. For these reasons, a substantial part of modern aquaculture is focused on developing captive reproduction mechanisms for a large number of species, eliminating the bottleneck of capturing larvae from the wild. Thus, most of the species reared today, particularly those with the highest production, such as finfish (carp, salmon, tilapia, bass, sole, etc.), bivalve molluscs (mussels, clams, oysters, etc.), and crustaceans (shrimp, crab, lobster, etc.) have at least three different production phases. The broodstock maintenance phase –​also known as maturation –​is where the conditions of the organisms in the reproductive stage are optimised, in such a way that they are kept free of pathogens and the quality of their offspring is also optimised. The stage of obtaining and maintaining larvae –​also known as hatchery –​is where the eggs are kept until they hatch with the last larval stages of the organism as the object of production. The fattening or final rearing stage is where juvenile organisms are kept and grown until they reach their commercial size. Additionally, in some species, an intermediate stage is considered between hatchery and grow-​out, known as nursery, where juvenile organisms are maintained and acclimatised to reduce the stress associated with inclusion in the grow-​out systems. Each of these stages or systems has marked differences in terms of rearing methods, care of water quality, volume of facilities and yields, so that, despite producing the same species, each system has handling peculiarities, such as different types of food and feeding methods. 2.3.4  Depending on hydrology

More than 70% of the surface of our planet is covered by water, of which about 2.5% corresponds to fresh water while the remaining 97.5% is marine water. Aquatic ecosystems are among the most diverse on the planet; in addition, they provide various services to humanity, such as fishing, tourism and transportation, among others. One of the most pressing aspects of climate change is the effect it is having on water, its abundance and availability. The survival of humanity and life as known until now is, to a large extent, associated with water. For these reasons, in addition to reared organisms, one of the most important resources for aquaculture farming is water. The selection of a culture site, target species and viability of an aquaculture company is inevitably associated with water. Thus, the way to obtain, channel and treat water is one of the most significant characteristics when defining an aquaculture system. Within this type of classification, two cultivation systems exist: open –​if water that enters the production system is returned to the environment after using it –​and closed –​if water that enters the system is reused/​recirculated. Different nuances exist for these two

18  Daniel Peñalosa Martinell classifications, which are of great importance in determining the impact that the production system will have. Within the open systems, those that use water exchanges naturally can be found; for example, production performed in a river or in cages in the ocean, and those that use artificial replacements to discharge high concentrations of nutrients through water pumping, as in shrimp in earthen ponds. The reasons for changing water can be various, such as improving water quality or creating a stream. Similarly to open systems, closed systems can also be found in the natural environment although to a lesser extent, for example, production in lakes. Although this type of system receives water external to the system, it does not have an outlet or a stream that distributes water through the system, so no replacements are available. However, artificial closed systems –​where water is recirculated within it and only lost through evaporation but replaced –​have gained much ground in aquaculture thanks to their ability to allow high culture densities and thus obtain a higher yield per m2 than in an open system. This system must be coupled with water quality control, which, done correctly, may reduce the risks of production by increasing control and facilitating handling. Some classic examples of closed systems are recirculation (RAS), zero discharge and aquaponic systems, which are described in more detail in other chapters. A new type of production known as semi-​closed containment systems is used mainly in salmon production.15 This type of system consists of floating elements with waterproof characteristics (either rigid such as concrete or plastic or malleable as some type of geomembrane) in which water is pumped from depths of from 20 to 50 m, no pathogens or phytoplankton that may be harmful to production exist. Pumped water can be treated by adding oxygen, mechanical filtration or other water improvement systems to maximise water quality and optimise production performance. Finally, water leaves the system by overflowing and returns to the medium. 2.3.5  Depending on the location of the facilities

Just as occurs with real estate, the success of aquaculture production has three relevant factors: “location, location, location”. The location of the facilities is crucial in aquaculture production. The geography, hydrology and climatology of the place can determine the success or failure of production. Access to markets, the presence of natural phenomena, operating costs, water quality and the characteristics of the species to be produced are just some of the variables that are defined by the location of the facilities. In turn, the choice of site is highly relevant when estimating the social, environmental and economic impacts of production. As for classification based on location, two large groups are identified –​ those that take place inland, simply known as “inland” and those in the environment itself. Inland productions can be performed in closed systems, such as greenhouses or industrial buildings, or they can be carried out in open systems, such as earthen ponds or rice fields. A classic example of inland production is shrimp farming in earthen ponds, a common practice in South America and Asia. Currently, an increasing commitment to inland production exists due to the ability to control

What is aquaculture?  19 the rearing medium (for example, in a recirculating aquaculture system or RAS), which allows for reducing the risks of biomass loss, producing on cheap land and being closer to consumer markets. Regarding production that takes place in water, open systems are found whether performed in floating cages on the sea, lakes or dams; or those that take advantage of the current of water bodies, such as the meander of a river to produce living organisms. The practice of producing marine organisms in their own environment is known as mariculture, whose most widespread example is salmon production in floating cages, as in the fjords of Norway, Scotland or Chile. These systems have advantages, such as lower operation costs, water quality and low energy consumption derived from the use of natural currents. However, they also have disadvantages, such as the environmental impact on the sea floor, exposure to natural phenomena, pathogens and predators, the risk of incurring biological contamination due to the escape of organisms to the natural environment, and overall lack of control. Today, semi-​ closed containment systems are shown as an alternative to use their advantages and reduce their disadvantages. Algae production is a great example of the differentiation of inland and production systems in water. Macroalgae are generally grown in stretched ropes in the sea, taking advantage of currents to avoid crop contamination and allow massive harvests with almost zero energy consumption. On the other hand, the production of microalgae is performed in inland systems because contamination of the environment is highly probable due to the special characteristics of this group of organisms, which makes intensive control of water quality and the necessary air provided. 2.3.6  Depending on the production objective

When aquaculture is discussed, in most cases, what come to our minds are industrial productions capable of producing thousands of tons of seafood with the aim of commercialising them on the international market to obtain economic benefits. While this idea defines industrial aquaculture, other types of aquaculture exist with different production objectives. One of them is production for self-​consumption –​ sometimes known as rural or small-​scale aquaculture. In this case, the objective of production is not necessarily to maximise economic benefits but rather product quality since its main objective is to serve as food for the producer or the community that produces it. In most of these cases, the extra production is resold in a local market or within the community itself –​sometimes exchanged for other goods and services. This type of production is characterised by being low capital intensive, using low densities, rudimentary infrastructure and, where possible, reducing the amount of feed provided. In most cases, these productions are related to low-​cost herbivorous and easy-​to-​use products, such as carp, tilapia or catfish. Their production does not require very high technical knowledge, and they are the main aquaculture tool to combat food poverty. Chapter 4 will further expand on these types of aquaculture.

20  Daniel Peñalosa Martinell Finally, production with the objective of alleviating the pressure that exists on species at risk or overexploited stocks is known as restocking aquaculture. After obtaining juvenile or adult organisms, they are released into their original environment with the priority of increasing native populations. Nonetheless, a few cases exist where the effect of restocking by these methods has been successfully demonstrated. Most of them correspond to sessile organisms, such as bivalve molluscs or closed systems, such as lakes or ponds. 2.3.7  Depending on the seed origin

One of the main bottlenecks when developing a technological package for the production of a new species is obtaining the seed, that is the reproduction of adult organisms to obtain juveniles for fattening or final rearing. In this sense, certain species, to date, have not been able to reproduce satisfactorily under controlled conditions, either due to difficulty in obtaining gametes from the reproducers or in most cases, due to very low survival rates. Thus, some species are caught in the natural environment, kept in fences for fattening and later commercialised, which is the case of the Mediterranean bluefin tuna (Thunnus thynnus)16 and European eel (Anguilla anguila),17 among others. Species whose reproductive cycle can be obtained completely in captivity and under controlled conditions are given the name of species with a closed cycle. On the other hand, the system in which obtaining seed is subject to wild populations is called capture-​based aquaculture or, in some areas, sea ranching. Some consider capture-​based not to be aquaculture itself but a hybrid between fishing and aquaculture, because it does not share certain characteristics that make aquaculture a sustainable option to provide the world with seafood since it depends on the supply of wild stocks, which in some cases are overexploited.18 2.4  Aquaculture current status Currently, aquaculture provides more than 50% of the total production of aquatic organisms destined for human consumption, 46% if the reduction for fishmeal and fish oil obtained from fisheries is included. Stability in fishery volumes –​originated by the natural characteristics of the resource together with the increase in demand for marine products at the global level –​urges aquaculture to increase its productive capacity.19 In addition to the contribution of aquaculture to food safety, this industry is responsible for providing direct employment to 20.5 million people worldwide. Because the majority of natural stocks are being overexploited or are at their maximum sustainable yield, fishing production has remained at constant levels in recent decades, coupled with continuous aquaculture growth. This has led to a shift in the proportion of the population employed in the seafood industry which has migrated from the fishing sector to aquaculture, rising from 83% and 17% in 1960 to 68% and 32% in 2016, respectively. When this situation is added to the estimated first sale value of aquaculture production of US$ 263 billion,

What is aquaculture?  21 it shows the broad impact of this industry in both social and global economic dimensions.5 Aquaculture growth has shown some drawbacks, of which the most important is environmental deterioration, mainly highlighting soil eutrophication, aquifer contamination, greenhouse gas emissions and contributions to climate change, contaminated effluent emission, and cultivation area abandonment, leaving them eroded and useless.20,21 One way to improve these negative impacts and promote the positive effects of the activity is through improvement in governance (both private and public; see Chapter 15) to accelerate implementing new technologies that target improvements in production systems, not only increasing yields but also maximising the positive social outputs and minimising the negative environmental impacts (see Chapter 16). Finally, the development of the aforementioned policies and technologies can only be achieved through a sufficiently funded research structure, both in applied and basic sciences. As several papers, books and interviews have demonstrated and described in different industries and areas of knowledge, to advance the activity from unsustainable production to a sustainable path, the decisions and development of aquaculture on sound science, technology advances and continuous improvement should strongly be supported. 2.5  Final remarks Aquaculture is an interdisciplinary science where biology, engineering, ecology and economics, among others, come together. It does not matter what type of system is used –​whether open or closed, intensive or extensive, inland or in the natural environment –​all systems have advantages and disadvantages. The impact they have on the environment, as well as the suitability of the selected system, depends on the location, characteristics of the area, the surrounding community and the species to be produced. In any case, it is important to consider the different alternatives that exist, so that the operation that optimises the production system is selected taking into account all the aspects that make up sustainability. Nowadays, aquaculture is starting to gain attention from the general public, including investors, government officers and knowledge generators, providing resources that were not available a couple of decades ago. The following sections of this book will deepen into each of these topics, their status and the main issues and techniques that exist today to tackle them. 2.6  Chapter review questions 1 What is the relationship between the circulation system and production site selection? 2 Why is it important to avoid sexual maturation during a fattening cycle? 3 What are the challenges for polyculture development and scaling up? 4 What is a semi-​closed containment system, and how does it operate?

22  Daniel Peñalosa Martinell 5 What are the objective differences in industrial, rural or small-​scale and restocking aquaculture? Recommended readings Barsanti, L., Gualtieri, P. (2006) Algae: Anatomy, Biochemistry, & Biotechnology. Taylor & Francis. Brusca R., Moore W., Shuster S. (2016) Invertebrates. 3rd edition. Sinauer Associates, Sunderland, Massachusetts U.S.A. pp. 1104. ISBN-​13: 978-​1605353753. Keenan T. (2018) Ichthyology: An Introduction to Fish Science. Larsen and Keller Education. pp. 235. ISBN-​13: 978-​1635497625. Nash C. (2010) The History of Aquaculture. Wiley-​Blackwell. pp. 236 ISBN: 978-​0-​470-​95886-​5. Sambamurty A.V.S.S. (2017) A Textbook of Algae. I. K. International Pvt Ltd. pp. 261. Stickney R. R. (2017) Aquaculture: An Introductory Text. 3rd Edition. CABI. pp. 337. ISBN: 978-​1786390103. Timmons M. B., Guerdat T. & Vinci J. (2018) Recirculating Aquaculture. 4th edition. Ithaca Publishing Company LLC. pp. ISBN: 978-​0971264670.

References 1 Nakajima, T., Hudson, M. J., Uchiyama, J., Makibayashi, K., & Zhang, J. (2019). Common carp aquaculture in Neolithic China dates back 8,000 years. Nature Ecology & Evolution, 3(10), 1415–​1418. 2 Fan Lee (5th Century B.C., China) Translated by Ted S. Y. Moo Chesapeake Biological Lab, University of Maryland, Solomons, Maryland 20688. The original document resides in the British Museum. 3 Kumar, G., Engle, C., & Tucker, C. (2018). Factors driving aquaculture technology adoption. Journal of the World Aquaculture Society, 49(3), 447–​476. 4 Garlock, T., Asche, F., Anderson, J., Bjørndal, T., Kumar, G., Lorenzen, K., Ropicki, A., Smith, M. D., & Tveterås, R. (2020). A global blue revolution: aquaculture growth across regions, species, and countries. Reviews in Fisheries Science & Aquaculture, 28(1), 107–​116. 5 FAO. (2022). The State of World Fisheries and Aquaculture 2022. Towards Blue Transformation. Rome, FAO. https://​doi.org/​10.4060/​cc046​1en 6 Jespersen, K. S., Kelling, I., Ponte, S., & Kruijssen, F. (2014). What shapes food value chains? Lessons from aquaculture in Asia. Food Policy, 49, 228–​240. 7 Pechenik, J. A. (2000). Invertebrates (Vol. 193). Singapore: McGraw Hill. 8 Terwilliger, N. B. (2015). Oxygen transport proteins in Crustacea: hemocyanin and hemoglobin. Physiology, 4, 359–​390. 9 Kasturi, S. (2015). Physiology of Finfish and Shellfish. New India Publishing Agency. 10 Chamberlain, G. W., & Lawrence, A. L. (1981). Maturation, reproduction, and growth of Penaeus vannamei and P. stylirostris fed natural diets. Journal of the World Mariculture Society, 12(1), 207–​224. 11 Pereira, L. (2021). Macroalgae. Encyclopedia, 1(1), 177–​188. 12 Won, E. T., & Borski, R. J. (2013). Endocrine regulation of compensatory growth in fish. Frontiers in Endocrinology, 4, 74.

What is aquaculture?  23 13 Hartnoll, R. G. (2001). Growth in Crustacea—​twenty years on. In Advances in Decapod Crustacean Research: Proceedings of the 7th Colloquium Crustacea Decapoda Mediterranea, held at the Faculty of Sciences of the University of Lisbon, Portugal, 6–​9 September 1999 (pp. 111–​122). The Netherlands: Springer. 14 Dunham, R. A., Majumdar, K., Hallerman, E., Bartley, D., Mair, G., Hulata, G., Liu, Z., Pongthana, N., Bakos, J., Penman, D., & Gupta, M., 2000, February. Review of the status of aquaculture genetics. In Aquaculture in the Third Millennium. Technical Proceedings of the Conference on Aquaculture in the Third Millennium, Bangkok, Thailand (Vol. 20, p. 25). 15 Balseiro, P., Moe, Ø., Gamlem, I., Shimizu, M., Sveier, H., Nilsen, T. O., Kaneko, N., Ebbesson, L., Pedrosa, C., Tronci, V. and Nylund, A. (2018). Comparison between Atlantic salmon Salmo salar post-​smolts reared in open sea cages and in the Preline raceway semi-​closed containment aquaculture system. Journal of Fish Biology, 93(3), 567–​579. 16 Ottolenghi, F. (2008). Capture-​based aquaculture of bluefin tuna. Capture-​based aquaculture. Global overview. FAO Fisheries technical Paper, 508, 169–​182. 17 Nielsen, T., & Prouzet, P. (2008). Capture-​based aquaculture of the wild European eel (Anguilla anguilla). Capture-​based aquaculture. Global overview. FAO Fisheries Technical Paper, (508), 141–​168. 18 de Mitcheson, Y. S., & Liu, M. (2008). Environmental and biodiversity impacts of capture-​based aquaculture. Capture-​based aquaculture, 5. 19 Costello, C., L. Cao, S. Gelcich, M. Á. Cisneros-​Mata, C. M. Free, H. E. Froehlich, C. D. Golden et al. (2020). The future of food from the sea. Nature, 588(7836): 95–​100. 20 Edwards, P. (2015). Aquaculture environment interactions: past, present and likely future trends. Aquaculture, 447, 2–​14. 21 Dong, S. L., & Gao, Q. F. (2023). Interactions between aquaculture and environment. In Dong, S. L., Tian, X. L., Gao, Q. F., & Dong, Y. W. (eds.), Aquaculture Ecology (pp. 129–​160). Singapore: Springer Nature Singapore.

3 What is sustainability? Daniel Peñalosa Martinell

Every transformation has a positive, negative, or neutral associated impact, which can modify the system performance in question and affect other related systems. In the case of sustainability studies, this system is made up of three different subsystems that are related to each other, namely the environment, economy, and society. These subsystems are known as the three pillars (or spheres) of sustainability. As in the previous chapter on aquaculture, this chapter is a brief introduction to sustainability sciences. First, the concept of sustainability, its history, and different working definitions for the book are provided, which meets our own needs without compromising the ability of future generations to meet their own. The three pillars of sustainability and the use of governance are explained as transversal tools to achieve sustainable production. Afterwards, the idea of sustainable aquaculture and its drivers are discussed. 3.1 Introduction The main characteristic that differentiates the human species from other biological organisms is the cognitive system, which allows for reasoning, reflection, introspection, forecasting, and planning. These abilities together with handling tools and materials give rise to the capability to transform inputs into products. All these characteristics are of crucial importance in the development of sustainability since these transformations of inputs into outputs have a consequent modification of the surroundings in different scales. According to the second law of thermodynamics, any transformation –​no matter how insignificant –​has a consequent change in the system, an increase in entropy. Thus, any input transformation has a positive, negative, or neutral associated impact, which can modify the performance of the system in question. In the case of sustainability studies, this system is the space humans live on, and its study is made up of three different subsystems that are related to each other, namely: environment, economy, and society. With this in mind, and because aquaculture is the food-​producing industry with the highest annual growth over the last three decades, it is fair to assume that it has had a significant impact on the system, and it should be evaluated fairly, DOI: 10.4324/9781003174271-4

What is sustainability?  25

Figure 3.1 Relationships among the three spheres of sustainability.

considering all the effects production has had on the aforementioned subsystems and the relationships that exist among them (Figure 3.1). 3.2  Sustainability pillars and the relationship between them When production accounts for the effects it has on the environment and economy, the system can be considered viable, that is, adequate environmental performance can be produced and maintained without being sustainable. An example might be poorly managed ecotourism where local culture can be eliminated, labour in slavery-​like conditions may occur, or the social fabric of an established community eroded to maximise economic benefits while being respectful of the environment.1,2 If the established criteria of good economic management with a social view are met, but the environmental impact is not taken into account, it may be considered equity. For example, the enormous infrastructure programmes developed by some governments to promote economic growth in a marginalised social sector that do not consider the environmental impact that such work entails, like deforestation, destruction of ecosystems and biodiversity, and greenhouse gas (GHG) emissions associated with the activity.3 The point where the objectives of social development intersect with those of environmental protection without considering the effect on the economy can be given the tag of “Bearable”. In these cases, the cultural and social fabric of the community are respected, and a minimal environmental impact is maintained. However, no economic growth objectives are achieved, which can lead to poverty,

26  Daniel Peñalosa Martinell hunger, and lack of education, among others. Some examples exist in indigenous communities in Latin America, Africa, and Asia where the per capita environmental impact is negligible, but no development is derived due to the absence of economic planning. This effect has caused, in the long term, the migration of these communities towards the cities, in search of economic opportunities, causing centralised development and losing human resources in the rural areas, which means a loss to the aquaculture industry of the future if the status quo is maintained. Thus, an activity can only be considered sustainable if the objective is to optimise the three aspects described above –​maximising the social benefit, respecting the local culture, its traditions, and social fabric –​at the same time as options are provided to maintain sustained economic growth. Considering these aspects allows creating jobs, reducing poverty and hunger, providing a dignified life to all the inhabitants of the planet while taking care of it, eliminating the destruction of ecosystems, managing natural resources in an adequate way, and reducing waste emission. If all these aspects are not considered, the activity might not be maintained indefinitely, therefore it cannot be considered as sustainable. Due to all the previously mentioned factors, sustainability can be understood in mathematical terms as an asymptotic objective, that is, we can get closer and closer to meeting this objective but we can never say it has been completely achieved, it requires continuous and sustained improvement. This situation has made the concept of sustainability difficult to understand and be accepted by the public. To bring it to reality, the concept of Sustainable Development was generated, which allowed bringing the idea of sustainability to its application, allowing human development while reducing impacts. In the current economic system based on neoclassical economic models, economic growth is associated with development, so it is quite common to find a semantic exchange going from sustainable development to sustainable growth. However, the concept of sustainable growth might be considered an oxymoron. According to the Romanian economist Nicholas Georgescu-​Roegen, the neoclassical theory of growth does not consider the scarcity of natural resources as an input to an economic system and pollutant production and waste as an output.4 These aspects of the system make infinite or “sustainable” growth impossible. 3.3  Sustainability throughout history Since the appearance of Homo sapiens approximately 250,000 years ago, transformations have affected the three aforementioned subsystems. However, the impact it has had on the social and economic subsystems compared to the environment can be differentiated based on the system’s plasticity. Although the three subsystems can be considered plastic (or resilient) because of their great capacity to adapt to changes, the social and economic subsystems can adapt to large changes in a short period of time. On the other hand, the environmental subsystem requires longer periods of time to recover from major shocks and changes with respect to the status quo, or in some cases, it cannot recover at all.

What is sustainability?  27 During the first great civilisations, substantial changes took place in the social fabric with characteristics that still endure today from some of the most basic social structures to the development of democratic systems. Regarding the economic perspective, some transformations still remain relevant today, for example, the development of trade or the appearance of currency around 650 BC. In the case of the environment, the scale and techniques used in the different transformations did not constitute a high enough impact to irreversibly alter the system, of which the most significant was the use of natural resources, such as wood, water, metals, and minerals. Certain ecosystem transformations followed, mainly those associated with the construction of buildings and urban infrastructure. These impacts increased during the Industrial Revolution where in the course of 100 years, from the 18th to 19th centuries, massive growth was recorded in the material wealth of humanity. Some of these significant changes were observed in economic (automating processes, reducing production costs, and increasing profits), social (labour requirements from an artisanal to an industrial system, increasing levels of inequality, migrations from the countryside to the city, and greater power in the war machine), and environmental (significant increase in energy consumption, mainly through the use of fossil fuels, exponential increase in greenhouse gas [GHG] emissions) systems. The rampant wood consumption in Germany was used as fuel to provide the energy needed in the metallurgical industry, which led Hans Carl von Carlowitz, a mining administrator, to develop the current theory of natural resource management. The term sustainability was used for the first time in his book Sylvicultura Oeconomica, also considered the first treaty in forestry, where he developed methods for sustainable forest management. His theory was that adequate management of forest resources can be maintained indefinitely, while an inadequate one could lead to depletion of the resource. Although the reasons for leading a sustainable life have been in the collective consciousness for a long time for different reasons, the changes caused by the Industrial Revolution and its consequences observed many decades later –​mainly in the environmental field –​have been one of the main motivations for developing what is known as sustainability sciences. During the 1980s, some of the countries with the greatest presence in the international economic panorama (the United States and the United Kingdom) followed a neoliberalist political agenda, characterised by the opening of markets and the trend of economic globalisation. This policy boosted production globally. The absence of regulatory bodies and legislation aimed at protecting the environment –​ together with the increase in the use of new technologies for generating energy through fuel combustion, such as gasoline or diesel –​resulted in significant environmental deterioration and wealth redistribution, increasing the inequality gap (making the rich richer and the poor poorer). Following the first world meeting on the environment held in Stockholm in 1972 (Stockholm Conference on the Human Environment, 1972) and in an attempt to tackle economic and environmental issues jointly, the United Nations created a special commission to address this issue. The creation of the World Commission

28  Daniel Peñalosa Martinell on Environment and Development (WCED) –​ later known as the Brundtland Commission –​ was approved in 1983. In 1987 the Brundtland Commission published a report entitled “Our Common Future”, also known as the Brundtland Report, where the term sustainable development would be coined and defined as the “development that meets the needs of the present without compromising the ability of future generations to meet their own needs”.5 This concept was born, mainly, from one idea: The Earth’s natural resources are finite, so if unbridled consumption continues, future generations will not be able to enjoy the same capacity for well-​being and development that we now enjoy. In other words, intergenerational inequity or injustice exists, which is evident mainly in rich countries, responsible for most of the consumption of natural resources. According to Wackernagel and Rees, if all humanity consumed the natural resources at the same rate as the richest countries, two planets Earth would be needed to satisfy this demand.1 Twenty years after the Stockholm Summit, the United Nations Conference on Environment and Development was held in Rio de Janeiro, Brazil, in 1992, also known as the Earth Summit or Rio Summit. At this conference, 179 nations from around the world agreed to adopt the program known as Agenda 21 developed for this meeting. The Brundtland Report and Agenda 21 are the documents that marked the path the United Nations would follow in subsequent meetings (Rio +​5 and the Johannesburg Summit in 1997 and 2002, respectively). These meetings gave rise to the Objectives of Millennium Development or simply Millennium Development Goals in 2000 with the objective of setting tangible goals (with associated indicators) to be achieved by 2015. These goals were divided into eight human development purposes, in which social aspects covered the first six objectives, emphasising aspects of poverty, gender equality, access to education, and health. The seventh objective sought to “guarantee the sustainability of the environment”, and the eighth and final one referred to economic aspects, seeking to “foster a global partnership for development”. As a result of this programme, a substantial improvement was achieved in various social aspects: the rate of people living in extreme poverty in developing countries fell from 47% in 1990 to 14% in 2015. At the global level, it went from 1,926 million people in 1990 to 836 million people in 2015. Mortality in children under five years of age was reduced by more than 50% globally, and gender disparity was eliminated in primary, secondary, and tertiary education in developing countries. Despite the good results in the social sphere, many challenges remain to achieve a society with equal opportunities. Gender inequality persists, with women being at a disadvantage in the labour market and suffering from discrimination and sexual abuse. Moreover, large gaps exist between the richest and poorest households and rural and urban areas, with millions of people still living in extreme poverty, hunger, and without access to safe water. If in the social field there is still a long way to go, the environmental field is not far behind. The final report of the Millennium Goals mentioned that climate change

What is sustainability?  29 and environmental degradation undermine the progress achieved and the most significant effect was observed in the most vulnerable groups.6 Overexploitation of the ocean is causing fish to reach very low turnover rates, reducing the number of fisheries that can be exploited to a biologically sustainable level.9 Biodiversity at a global level has been reduced, both in quantity and distribution, increasing the number of endangered species.7 In addition, since the poorest sector depends to a greater extent on natural resources and is located in areas of greater vulnerability, it is the one that has suffered the most from the effects of environmental degradation and climate change. Facing this new development stamp and once the Millennium Goals programme was concluded, the UN gave rise to the programme known as the Sustainable Development Goals (SDGs) as a follow-​up programme, whose application started in 2015 and which is planned to have been concluded by the year 2030. In total, the SDGs consisted of 17 goals, within which all the social characteristics were found in the Millennium Goals, such as the elimination of extreme poverty and hunger in the world and the search for gender equality. In addition to these goals, greater emphasis has been placed on the challenges posed by environmental deterioration with various objectives referring to it, for example, seeking “to adopt urgent measures to combat climate change and its effects” (Goal 13 of the SDGs, UN). The use of the word sustainable was observed 12 times along the descriptions of the 17 SDGs, as opposed to the Millennium Goals where it is mentioned only once. Thus, in most cases, objectives are sought to consider all the aspects involved in the sustainability criterion. 3.4  Sustainability, an elusive definition At the time of its inception, the concept of sustainable development itself was greeted with excitement and scepticism in equal measure. The term development applied to the current socio-​economic and political system implies, among other things, economic growth, and as the Brundtland Report stated at the time, this development is limited by the current state of technology and social organisation. Although no significant technological advances have taken place since the report was published, these limitations are still evident, mainly in relation to energy generation and the associated greenhouse gas (GHG) emissions.2 The report projects scenarios where an increase in industrial production from five to 10 times is expected compared to that observed at the time of its publication. Assuming that the technology to achieve the desired existing economic growth is enough, the social organisation must change significantly if the needs of society as stated in the report are to be met, which states that the essential needs of the world’s poor must be given top priority. While a vague common agreement exists on the definition of sustainability based on the proposal provided by the Brundtland Report, more than 300 definitions of the concept have been made. The ambiguity of this definition has given rise to different appreciations and nuances. Today, the lack of clear semantics and the difficulty of properly defining the concepts that encompass sustainability are two of the most significant barriers to developing

30  Daniel Peñalosa Martinell this multidisciplinary branch of science, thus being the source of multiple cases of greenwashing. Despite the efforts of the scientific community, as well as different organisations, both public and private, it has not been possible to develop a definition of the term sustainability that lacks ambiguity and is accepted and used by the majority of experts in the field. The existence of too many definitions –​ added to the application (sometimes arbitrary or exaggerated) of the term sustainability –​ has made its use lose impact or cause misunderstandings. According to several researchers, the word sustainability is one of the least significant and most used words in the English language. In areas such as politics, advertising, or marketing, the terms sustainability and sustainable development are used as an abstract concept of responsibility (usually associated with caring for the environment). The word sustainability has become a fad and a categorical imperative of responsibility for creating something new; it has become synonymous with progress, equality, responsibility, and culture. In the words of Diefenbacher et al. “whoever wants to achieve something, must show that he or she intends to achieve it in a sustainable way”.8 Numerous efforts have been made to define the concept, of which the most accepted is the one defined as the practice that allows satisfying current needs without undermining future well-​being. This definition is very similar to the one expressed in the Brundtland Report. According to that previously mentioned, although finding a definition of sustainability truly seems to be the best in terms of the study and performance of this science, it is also true that the lack of clarity should not be an obstacle to implementing sustainable practices. In fact, according to Ramsey,9 a definitive definition of the term may not be possible to find since it depends on the context, so the important thing is not so much the precise definition but the performance of sustainability. To this day, the definition used by the Brundtland Report continues to be the one that has the greatest number of followers, as it emphasises the most important principle that addresses sustainability and sustainable development, which is its intergenerational characteristic. Thus, two relevant dimensions can be found when talking about sustainability. On the one hand, the spatial dimension, which refers to the location where the impact takes place. For example, the environmental effect of the conversion of shrimp production areas in an arid zone is not the same as the conversion of a mangrove. On the other hand, the time dimension considers the effect that production has over a period of time, and in turn, the time it would take to recover it. Thus, sustainability is made up of three spheres (or pillars) and two dimensions. 3.5  Types of sustainability In addition to the ambiguity of the concept, different approaches exist to understand how to achieve sustainability. From the point of view of economic theory,

What is sustainability?  31 two types of sustainability can be found –​strong, also known as environmental sustainability, and weak, also called economic sustainability. The definition of weak sustainability comes from the neoclassical theory of economic growth defended by various great economists of our times, such as Robert Solow.10 Pearce and Atkinson11 defined weak sustainability as one whose savings rate is equal to the combined depreciation rate of environmental and human capital. In other words, weak sustainability is one in which the environmental and social capitals of a productive system are interchangeable. For example, from this point of view, companies that have negative environmental externalities (such as contamination of aquifers or greenhouse gas emissions) are considered sustainable as long as they have a positive externality of equal magnitude as a counterpart, e.g., through the payment of a tax, a fine, or a reforestation programme. Strong sustainability, defended by ecological economics with Nicholas Georgescu-​Roegen as one of its pioneering exponents, considers that the environment is irreplaceable and no sufficiently valuable counterpart exists to counteract the loss of natural capital. In other words, environmental deterioration, loss of natural resources, and pollutant production cannot be exchanged for a monetary equivalent as taxes or programmes. Thus, in strong sustainability, no exchange exists between environmental and social capital, which is why governance of prohibition, fines, and incentives is chosen to reduce the negative social and environmental impact. In recent years, other approaches have been selected, such as the strength of the buyers and raising awareness and education of society to instil a feeling of responsibility towards the rest of humanity and future generations, in such a way that consumption is reduced and people opt for companies that are more aware of their impact and seek to minimise it by implementing new technologies or best practices. On the other hand, it is important not to confuse sustainability with environmentalism. Although the concern for sustainability stems from the finite characteristics of natural resources, the concept encompasses much more than just caring for the environment. Social justice, wealth distribution, and food security, among others, are key concepts of sustainability and do not appear anywhere in environmental theory. Misunderstanding of the term may cause even students or researchers to confuse sustainability with other concepts –​in the case of those with a greater inclination towards social sciences with rural development, or with climate change for those with a greater ecological inclination. Although both concepts are included within sustainability and “sustainable development”, it goes much further. Thus, all the aspects that encompass the system to direct and govern it in a fair and equitable way both inter-​and intra-​generationally should be considered. 3.6  Managing sustainably: the concept of governance The world has immense ecological and cultural diversity. On some occasions, these concepts confront each other, and are associated with a neoclassical concept of

32  Daniel Peñalosa Martinell economic development, finding conflicts that can lead us away from sustainable development. This conflict increases in the case of natural resources, falling into the paradigm described by William Foster Lloyd and later expanded and demonstrated by Garrett Hardin called the tragedy of the commons.12 Simply put, the tragedy of the commons says that assuming individuals act rationally, independently, and motivated by a personal interest in the face of common (or shared) and limited goods, such as the atmosphere, forest, or fish in the ocean, they end up being destroyed even if it is not convenient for any of the participants in this common good. An example can be seen in the international fishing scene. Before 1982, the absence of a legal framework to regulate international fishing caused several fisheries in the world to collapse due to the open access system for this resource. A second aspect is fundamental to understanding the existence and functionality of governance and is the concept of externalities –​an idea attributed to Alfred Marshall and later deepened by Arthur Pigou. In summary, an externality can be defined as an activity done by one individual or group that affects others without being compensated or providing any compensation. Externalities can be positive when the effect of the activity performed has a positive impact on a third party (such as the effect of higher education on society as a whole) or negative when the activity produces a cost or damage to a company or third party (such as the pollution of the atmosphere associated with GHG emissions). To avoid the negative effects of the tragedy of the commons and hold the actors responsible for their externalities in cases where property rights are not well defined, various authors have proposed the intervention of organised systems. These systems should establish a series of rules of the game, managing the use of resources in a rational, and in our case, sustainable way, while assigning rights and responsibilities to the users of such resources. This management system can be called governance. Just like with sustainability, the complexity that surrounds the concept of governance makes it difficult to define in a simple way. However, a first statement can be made to frame the concept and serve as a reference for future mentions of the topic: Governance refers to the management, both public and private, of an organised system, setting standards and enforcing them. This concept and its applications in aquaculture are discussed in more depth later; however, an introduction to the topic is essential since governance is one of the keys to achieving sustainability in any system, including aquaculture. Governance is considered, if not a fourth pillar of sustainability, an essential cross-​cutting tool for sustainable development that must encompass the three spheres of sustainability and provide a fair and optimal legal framework or “rules of the game”, so that all the aspects that make up sustainable development may be balanced.

What is sustainability?  33 3.7  Aquaculture and sustainability Whether an immense production in the sea with the aim of amassing wealth or a small one in the field is destined to produce food for the farmer, the production may have characteristics that make it sustainable or not. Throughout the following chapters, we will delve into how aquaculture touches all the spheres of sustainability. On the economic sphere the industry has an estimated global first-​sale value of more than 250 billion dollars annually.9 Furthermore, the supply chain worldwide is interconnected, which not only has a significant impact on the environmental footprint of the products obtained but also on the future economic development of certain nations. Regarding the environmental sphere, poorly managed aquaculture can have severe and irreversible environmental impacts. For example, the elimination of ecologically important areas such as mangroves, GHG emissions derived from extreme energy consumption, soil eutrophication leading to the abandonment of cultivation areas, contamination of the seabed in floating cage productions, elimination of benthic organisms with low or no capacity for movement, hyper-​nutrition of coastal and continental areas can lead to algal blooms and red tides, among others.13,14 Aquaculture plays an important role in the social sphere at a global level, with the livelihoods of more than 20 million people around the world depending directly on aquaculture development. Even with this in mind, various debates have taken place regarding the quality of employment provided by aquaculture and its distribution in terms of gender, with only 19% of women employed in the primary aquaculture sector, although this number changes to circa 50% when the postharvest process and added value are considered.15 How to produce has also been a matter of debate. The use of ingredients from fishing produces an imbalance with respect to the quantity of fish obtained from fishing and used to feed carnivorous aquaculture species (fish in) and the number of fish produced (fish out). In addition, discussions about the contribution that these species have to food security have taken place since they are mostly species of high commercial value, such as salmon, tuna, or marine shrimp, and in some cases, meat quality may be compromised due to poor diet or improper production process. Nevertheless, fish consumption represents one-​sixth of the animal protein consumed in the world and up to 50% in some countries.9 Sustainability is based on the concept of intergenerational justice in providing future generations with at least the same resources and opportunities currently available to generate wealth and well-​being. For this reason, it is essential not to lose sight of all the aspects that make up the system, seeking a balance that allows prolonged production over time. In the case of aquaculture, this capacity depends on management, law, environmental conditions, infrastructure, and scientific knowledge. Improper production management can lead to severe environmental degradation with the loss of important ecosystems and can even put human health at risk. Moreover, the

34  Daniel Peñalosa Martinell search for maximising financial benefits can lead to an irresponsible administration where –​in addition to environmental deterioration –​unfair labour conditions exist. To avoid these mishaps, a legal framework that regulates aquaculture activity is necessary, establishing the bases or limits that should not be crossed in terms of the production impact. In this sense, environmental regulation has improved significantly, mainly in developed countries such as Norway and Scotland. However, there remains a long way to go in terms of the regulation of supply chains. Recent studies have shown that a connection exists between companies with sustainable labels and food producers that use products obtained from unsustainable fishing, which is significant because one of the negative impacts of aquaculture is the excessive consumption of fishmeal and fish oils to feed the organisms produced. One of the difficulties in the application of standards for production is monitoring the activity to ensure that the standards are met and –​otherwise –​the appropriate sanctions are applied. Adequate aquaculture regulations with a view to sustainability require a definition of the concept of sustainable aquaculture. Thus, sustainable aquaculture can be defined as any aquaculture practice that seeks to maximise social and economic benefits while minimising negative environmental impacts, allowing production to be maintained indefinitely over time. Infrastructure can significantly define the impact of production. The system in which the organisms are maintained, technology is used to generate energy, management of effluents and waste, and materials are used for construction, among others, define the environmental impact of operations. For example, during shrimp larval production, it is essential to keep the water temperature close to 30°C. In many cases, this is achieved by heating seawater through the use of combustion boilers, but in some laboratories, other more environmentally friendly methods are already used, such as geothermal energy. The method used for this effect determines the GHG emissions, which –​ as shown in Chapter 6 –​ is key in the development of climate change. Likewise, the technology used to manage water determines the volume to be heated, thus the energy used and GHG emissions.16 Another example is the use of recirculation systems that allow reusing culture water indefinitely, as long as adequate treatment is provided, only recovering that which is lost through evaporation. In this way, contamination of the natural environment can be contained, eliminating the discharge of nitrogenous waste, medicines, and other treatments that can have a negative impact on the ecosystem. One of the characteristics that weak sustainability defends is that increasingly accelerated technological development makes it possible to limit negative environmental impacts. Since the global idiosyncrasy has a neoclassical tendency, it is important to promote scientific and technological development, so these impacts can be effectively reduced. Although various methods and techniques are already used to reduce environmental impacts, it is important to mention that in many cases

What is sustainability?  35 they are just projects or prototypes, though promoting the development and implementation of these technologies needs to be a priority for all stakeholders. 3.8  Final remarks Sustainability is a concept that encompasses a dynamic objective, meaning it is impossible to be fully achieved, since it changes over time, nonetheless, it is getting increasingly closer to being achievable and a significant step forward. The development of new technologies, increase of scientific knowledge, governance, awareness of humanity, and long-​term investment are some of the tools necessary to promote increasingly sustainable aquaculture. Therefore, aquaculture production can be increased, provide employment and quality food to the global population, minimise negative environmental impacts, and promote economic growth. For aquaculture to attain sustainability, all components (or pillars) need to be accounted for, not only the environmental aspects but also the social and economic outputs. 3.9  Chapter review questions 1 Which are the three pillars of sustainability and which are the most important transversal tools to achieve it? 2 In your words, what do you understand by sustainability? 3 Are sustainability, sustainable development, and sustainable growth the same thing? 4 What is the definition of sustainable aquaculture? 5 What is the main difference between strong and soft sustainability? Recommended readings Brinkmann R. (2016) Introduction to Sustainability. Wiley-​Blackwell. ISBN: 978-​1-​118-​48714-​3. Brundtland, G. H., Khalid, M., Agnelli, S., Al-​Athel, S., & Chidzero, B. J. N. Y. (1987) Our Common Future. New York, 8. Caradonna, Jeremy L. (2014) Sustainability: A History. Oxford University Press. Clark, W., Harley, A. (2019) Sustainability Science: Towards a Synthesis. Sustainability Science Program Working Papers. FAO. (2020) The State of World Fisheries and Aquaculture 2020. Sustainability in Action. Rome. https://​doi.org/​10.4060/​ca92​29e. Giovannoni, E., Fabietti, G. (2013) What is sustainability? A review of the concept and its applications. In: Busco, C., Frigo, M., Riccaboni, A., Quattrone, P. (eds) Integrated Reporting. Cham: Springer. https://​doi.org/​10.1007/​978-​3-​319-​02168-​3_​2 Heinrichs H., Michelsen G., Wiek A. & Martens P. (2015) Sustainability Science: An Introduction. Springer. ISBN 978-​94-​017-​7242-​6. Jacques, P. (2020) Sustainability: The Basics. Routledge.

36  Daniel Peñalosa Martinell Jackson, T. (2009) Prosperity Without Growth: Economics for a Final Planet. London: Earthscan. Scoones, I. (2007) “Sustainability.” Development in Practice 17.4-​5: 589–​596.

References 1 Belsky, JiU M. (1999). Misrepresenting communities: The politics of community-​based rural ecotourism in gales point manatee, Belize 1. Rural Sociology, 64(4), 641–​666. 2 Newsome, D. (2013). An ecotourist’s recent experience in Sri Lanka. Journal of Ecotourism, 12(3), 210–​220. 3 Ceceña, A. E. En plena catástrofe ambiental ¡el Tren Maya va!. (2020). 4 Georgescu-Roegen, N. (1971). The Entropy Law and the Economic Process. Cambridge, MA and London, England: Harvard University Press.. 5 Brundtland, G. H. (1987). Our Common Future: Report of the World Commission on Environment and Development. Geneva, UN-​Dokument A/​42/​427. 6 United Nations UN. (2015). The Millennium Development Goals Report 2015, Working Papers id:7222. 7 UN Secretary-​General’s speech at the Countdown to COP15: Leaders Event for a Nature-​Positive World in September 2022. 8 Rees, W., Wackernagel, M., & Inch, J. (1997). Our ecological footprint: reducing human impact on the earth//​Review. Alternatives Journal, 23(2), 35. 9 Ramsey, J. L. (2015). On not defining sustainability. Journal of Agricultural and Environmental Ethics, 28(6), 1075–​1087. 10 Solow, R. M. (1993). Sustainability: an economist’s perspective. Economics of the Environment: Selected Readings, 3, 179–​187. 11 Pearce, D. W. & Atkinson G. D. (1993). Capital theory and the measurement of sustainable development: an indicator of ‘weak’ sustainability. Ecological Economic, 8, 103–​108. 12 Hardin, G. (1968). The tragedy of the commons: the population problem has no technical solution; it requires a fundamental extension in morality. Science, 162(3859), 1243–​1248. 13 Peñalosa Martinell, D., Vergara-​Solana, F. J., Almendarez-​Hernández, L. C., & Araneda-​Padilla, M. E. (2020). Econometric models applied to aquaculture as tools for sustainable production. Reviews in Aquaculture, 12(3), 1344–​1359. 14 Naylor, R. L., R. W. Hardy, A. H. Buschmann, S. R. Bush, L. Cao, D. H. Klinger, D. C. Little, J. Lubchenco, S. E. Shumway, & M. Troell. (2021). A 20-​year retrospective review of global aquaculture. Nature, 591(7851), 551–​563. 15 FAO. 2022. The State of World Fisheries and Aquaculture 2022. Towards Blue Transformation. Rome, FAO. https://​doi.org/​10.4060/​cc046​1en. 16 Peñalosa-​Martinell, D., Vela-​Magaña, M., Ponce-​Díaz, G., & Padilla, M. E. A. (2020). Probiotics as environmental performance enhancers in the production of white shrimp (Penaeus vannamei) larvae. Aquaculture, 514, 734491.

Part II

Aquaculture and the environment

4 Effects of the environment on aquaculture organisms Daniel Peñalosa Martinell

Just as aquaculture has an impact on the environment, the environment affects aquaculture and its performance. Different environmental components affect aquaculture groups differently, we will focus mainly on finfish, molluscs and crustaceans, with some references to other groups, such as algae. How does temperature affect organisms’ performance? Why does dissolved oxygen behave in water and how does that affect aquaculture? Is pH relevant to all aquaculture species? and How can other environmental components improve or reduce the performance of certain species in specific parts of the world? Some relevant biological aspects of different species groups important to aquaculture production are considered in this chapter to understand the effect that some climate change aspects may have on aquaculture and how they could impact the industry. 4.1 Introduction All living beings are affected to a greater or lesser extent by the surrounding environment. For example, the right temperature, amount and quality of light and water will determine if a plant at home lives or dies, whether it grows and flowers or if it remains small and struggles to survive. In the case of aquaculture animals –​due to the relationship they have with their surrounding environment and their physiological characteristics described in Chapter 2 –​changes in their surrounding environment have a higher impact than that observed on terrestrial vertebrates common in animal protein farming. The water surrounding them is an important catalyst of chemical reactions and interacts permanently with them through contact, which affects their internal organs and structures where most physiological processes where most physiological processes occur. These biological facts make them especially sensitive to physicochemical changes in the water. The components that define water composition and its characteristics are known as water quality. As mentioned in Chapter 2, three biological characteristics make an aquatic organism an ideal candidate for aquaculture: rapid growth, ability to reproduce in captivity, and broad fecundity. In addition, they should preferably have high tolerance to handling and a high survival rate in captivity. All these faculties are directly impacted by (1) organism biology (intrinsic) and (2) the surrounding environment DOI: 10.4324/9781003174271-6

40  Daniel Peñalosa Martinell and its physicochemical characteristics (extrinsic), that is, water quality and its biological components. The most significant water quality parameters in aquaculture production –​ regardless of the organism produced –​ are: temperature, dissolved gases (mainly oxygen), salinity, pH, dissolved particles (especially nitrogen compounds), suspended particles, and photoperiod (this parameter is not a component of water quality per se, but may have an impact on it and on rearing organisms). To evaluate the determining factors of water quality, three reference points are used to define the curve that establishes water quality in reference to each of them. Critical points are those that define the ends of the curve (lower and upper), while the optimal point is the one that defines the performance maximisation of each biological aspect (Figure 4.1). Thus, these points for each of the water quality parameters and specific for each species produced are important. The producer attempts to maintain these parameters at their optimal points to maximise the performance of the organisms produced. In the case of limiting factors (defined as anything that constrains a population's size and slows or stops it from growing, such as dissolved oxygen levels or ionised ammonium concentration), this yield curve is different. In this case, maximum or minimum tolerance points are observed from which problems in the development or survival of the organisms begin to appear. All the physicochemical factors that determine water quality have to be considered by the farmer, since in many cases changes in one of the components may have significant effects on the rest, varying the performance of farmed organisms.

Figure 4.1 Biological performance curve and its relationship to water quality physicochemical parameters in aquatic organisms.

Effects of the environment on aquaculture organisms  41 4.2 Temperature Water temperature is considered the most important environmental factor affecting fish and shellfish growth, with growth occurring within a limited thermal range and the temperature regime determining the length of the growing season. The growth rate may vary with age, with ontogenetic shifts in thermal niches occurring as the fish age. All farmed aquaculture organisms are ectothermic, that is, their body temperature is equal to the temperature of the environment. This characteristic makes water temperature a determining factor in rearing or breeding any aquaculture organism. With that in mind, Langford (1990) divided aquatic organisms into three groups: Cold stenotherms: the organisms which possess narrow tolerance ranges in cold water regions, like the Arctic. Warm stenotherms: the organisms with slim tolerance ranges in warm regions, like the tropics. Eurytherms: the species with broad tolerance ranges, e.g. in temperate or sub-​ tropical Regions.1 When it comes to growth, temperature can play several roles in determining it. In most cases, growth has been found to increase as temperature increases until reaching the maximum growth; from this point on, increases in temperature do not translate into growth increases. The temperature where growth is maximum is known as the optimum growth temperature, which is specific for each species, age, and, sometimes, for each genetic variety. The reasons behind why temperature affects growth are varied and complex, and the thresholds can change depending on the size or age of some organisms. According to various studies performed on different fish and crustacean species, one of the most relevant is that a great variety of digestive enzymes are activated to a greater extent when the temperature rises, which leads to greater nutrient absorption from food, making better use of the energy consumed to apply it to growth. Another biological effect observed in wild fish is the increase in the presence of the growth hormone in times when temperature is higher, with peaks in spring and summer. As discussed in Chapter 2, this hormone is directly related to growth in finfish and is one of those responsible for regulating it. In addition to the optimal growth temperature, two critical points are found in which the organism in question cannot survive: lower and upper lethal temperatures. These two points plus the optimal growth temperature mark the tolerance curve of each organism as a function of rearing temperature. When water quality is evaluated, the temperature always has to be as close as possible to the optimal growth values. Low temperatures slow down the metabolism of organisms. At low temperatures, aquaculture organisms reduce their feed intake and maximise energy use to maintain their minimal survival functions, reducing growth. If the temperature continues

42  Daniel Peñalosa Martinell to drop, haemolymph or blood density increases, and circulation becomes more difficult. At the lowest lethal temperature, the body is unable to maintain its minimal vital functions and dies. In the case of some algae, because of the totipotency of their cells, the minimum lethal temperatures are usually extremely low. Typically, the lowest lethal temperature for these organisms is at which crystals form in the cell membrane or wall, breaking it down and eventually killing the cells that make up the organism. According to a report published by the Water Research Commission of the Republic of South Africa “mortality in fish from acute exposure to elevated temperatures is often the result of metabolic malfunctions (including fluid electrolyte imbalance, alterations in gaseous exchange and osmoregulation, hypoxia of the central nervous system and inactivation of enzyme systems”.2 Excessively high temperatures are stressors for ectothermic organisms.3 High temperatures can alter the correct protein production and even destroy or completely denature them; they can also alter DNA expression through an epigenetic process known as methylation, causing important phenotypic changes.4 Another reason why extremely high temperatures have a harmful effect on organisms is their relationship with dissolved oxygen. The higher the temperature is, the less dissolved oxygen is available to reared organisms. In addition, if microalgae or bacteria are found in the tank, the increase in temperature favours their reproduction, further reducing oxygen availability, especially at night. In addition to organism growth and survival, temperature plays a crucial role in the maturation and reproduction of most aquaculture organisms. Fish, crustaceans, molluscs, and algae use physicochemical factors from the environment to determine the time of year and thus follow strategies to maximise the survival of their offspring. In the natural environment, temperature and light are two crucial factors in determining the ideal moment for the release of gametes. These characteristics allow aquaculture producers to manage the organism performance produced by manipulating the environment. An example can be observed in the release of gametes by some bivalve molluscs. In seed production laboratories of some bivalves, such as oysters and mussels, temperature stress through sudden changes (also known as temperature shocks) is used as a tool for the release of gametes. Temperature also affects the feeding habits of certain organisms, a characteristic that directly impacts aquaculture, particularly fed aquaculture, since feeding determines growth and hence the length of the cycle might affect water quality and production costs. Temperature has been proven to be one of the determining factors for feeding rates, considerably changing within the same species at different temperature ranges.5 The effect of temperature is not limited to the individual biological processes of organisms, it can also affect the trophic relations between species and their geographical distribution (for a deeper study on the relationship between temperature and aquatic organisms see Dallas, 20082). Temperature is also directly related to the speed of some chemical and biochemical reactions, which means that it also has a direct effect on most of the other indicators described in this chapter.

Effects of the environment on aquaculture organisms  43 4.3  Dissolved gases Water and its composition are not the only elements that affect reared organisms. In aquaculture, the air–​water interface is highly relevant. Dissolution of gases from the atmosphere in the environment, as well as the consumption and emission of gases from the organisms in the ponds, has a significant effect on crop survival and its correct development. In this sense, two concepts are fundamental to understanding the presence or absence of these gases in the aquatic environment. The first concept is dissolving gas in a liquid. This phenomenon was described by the English scientist William Henry, who stated that gas dissolution in water at a constant temperature is directly proportional to the partial pressure exerted by that gas. In other words, gas dissolution is given, mainly, by pressure and temperature. The second fundamental concept for aquaculture is gas diffusion, that is, the speed at which a dissolved gas is distributed through the water column. This concept can be described using Fick’s laws, defined by the German physiologist Adolf Fick, where he describes the motion of a solution with two different gradients through a system of differential equations. Although these equations are complex, they are based on a logical concept, namely, the diffusion of a solute (in this case a gas) through a solvent (in this case water) depends on the concentration gradient. In the case of gas diffusion in an aquaculture system, this difference in gradients occurs in the areas of contact between the gas and liquid phases. In the case of air injection, the speed with which the bubble travels the space from the injection to its exit into the atmosphere, and the size of the bubbles (the area of contact) determines the contact time of the liquid–​gas phases, determining the diffusion capacity of that system. In aquaculture, two naturally occurring gaseous compounds exist that have a significant effect on the performance of reared organisms –​ dissolved oxygen and CO2. 4.3.1  Dissolved oxygen

Oxygen is one of the most important elements to guarantee the survival and correct development of animals. Oxygen is a key element in the chemical reactions by which cells generate energy, since it is essential and irreplaceable in most metabolic processes in higher organisms. Unlike terrestrial animals that take in gaseous oxygen mixed in the air, aquatic organisms depend on gaseous oxygen dissolved in water (DO) (which should not be confused with the oxygen that makes up the water molecule) captured through the respiration process performed in the gills or skin in the case of some animals. It also plays a significant role in the respiration of algae as a product during the diurnal phase and an input during the nocturnal phase. According to Henry’s Law –​ first formulated by the English physician and chemist William Henry in 1803 –​oxygen gas dissolution in water is directly related to other environmental components: temperature, partial gas pressure, and fluid in

44  Daniel Peñalosa Martinell which the oxygen dissolves. The higher the temperature is, the lower the oxygen solubility is, therefore, the lower the availability is to organisms. In addition to temperature, other factors directly affect dissolved oxygen availability, for example, salinity. As with temperature, increases in salinity have an inverse effect on oxygen availability. While logically low oxygen availability results in high mortalities, the relationship between dissolved oxygen and growth is less obvious but just as important. An oxygen concentration above the lethal but below the optimal concentrations can result in growth deficit. This result is due to the implication of this element on metabolism and nutrient absorption capacity, besides the energy generation used to grow and regenerate tissues. In addition, low oxygen concentrations have been proven to generate a hormonal response that reduces appetite, prioritising its use to maintain vital signs. Along with optimal DO levels, it is important to keep them stable, drastic changes in dissolved oxygen levels have been linked to a greater deleterious effect than sustained low oxygen availability. The relationship between reproduction and low oxygen availability is similar to what is observed in growth. Facing low oxygen concentrations, most aquatic animals reproduce little or not at all, since the development of their sexual organs can be inhibited, preventing gamete production or significantly reducing their quality, and thus, the ability of the offspring to survive. Embryos developing under hypoxic conditions may show hatching difficulties and phenotypic abnormalities in hatched organisms that can even result in their subsequent death. In the case of fish, unlike what happens with growth, new studies have shown that it is not mainly due to the reduction of metabolic activity that reproduction is stopped or reduced, but also to an effect on hormonal signalling, inhibiting a series of neurotransmitters and receptors in the hypothalamus–​pituitary–​gonads axis. 4.3.2  Carbon dioxide (CO2)

Just as it is desirable for the producer to maximise dissolved oxygen availability in water, it is also relevant to seek how to minimise the negative effects that CO2 dissolution may have in it. CO2 is the metabolic result of aerobic respiration, both of reared organisms and the various microorganisms that may be found (including the dark phase of photosynthesis in microalgae). In high concentrations, CO2 can affect the oxygen transfer capacity in the blood of reared organisms, so excessive accumulation of this gas should be avoided. This situation is particularly important in water recirculation systems (RAS), since the water that leaves the system is loaded with CO2; thus, if adequate treatment is not available, it is reintroduced until it reaches saturation levels. This problem is easily controllable through the use of degassing systems, such as packed columns or temperature or pressure degassing. Similar to the biological effects of this gas, an important balance exists between CO2 concentrations, pH, and calcium carbonate availability (see Section 4.6), which can have a significant effect on shell-​forming organisms.

Effects of the environment on aquaculture organisms  45 4.4 Salinity The effects that the salinity of the medium has on reared organisms are related to the concept of osmotic pressure, defined as the pressure that must be applied to a solution to stop solvent net flow through a semi-​permeable membrane. Faced with an ionic concentration difference, osmotic pressure causes the passage of solvent molecules (e.g. water) through the semipermeable membrane, towards the part with the highest solute concentration (e.g. chlorine, sodium, potassium). In this manner, the difference in concentration decreases, therefore, the osmotic pressure also does. In the absence of osmotic regulatory mechanisms, a hyposaline (or hypotonic) environment compared to the cell interior results in water entry through the membrane, which can lead in extreme cases to cell membrane rupture or cytolysis. On the other hand, if the environment is hypersaline (or hypertonic), water tends to leave the cell through its semi-​permeable membrane, which can cause dehydration and, in extreme cases, a type of cell death known as crenation (due to its shape) or plasmolysis. Due to the difference that exists between the internal ion balance of aquaculture organisms and the environment, fish and other aquatic organisms perform a metabolic process of ionic balance known as osmoregulation, which consists of actively regulating the ionic balance between the inside and outside of the semi-​ permeable membranes. The regulatory capacity is variable and depends on each species (Figure 4.2). Organisms that are able to survive in wide ranges of salinity are known as euryhaline, and those that can survive in narrow ranges of salinity are described as stenohaline. Salinity also directly impacts growth besides its relationship to survival. First, osmoregulation processes are costly from an energy point of view, so the further the medium is from optimal salinity, the more energy goes into regulating the ion

Figure 4.2 Osmoregulation process and differences between freshwater and marine fish.

46  Daniel Peñalosa Martinell balance, and the slower growth is. On the other hand, as mentioned above, high salinities have a lower oxygen dissolution, and therefore, lower availability of this gas, which can be associated with reductions in growth and reproduction. 4.5 pH On many occasions, aquaculture producers ignore the effect that pH has on production since it is not directly observable as a sudden change in temperature or the availability of dissolved oxygen. However, a sudden change in pH can result in reduced feeding rates, depression of the immune system –​therefore, worse performance of cultured organisms –​and in extreme cases, death. Small changes in water acidity or alkalinity can also have significant effects on most organisms. On the one hand, although the relationship between pH and oxygen solubility in water is not direct, it does affect the ability of animals to absorb and use this oxygen and, depending on water conditions, it can reduce its availability. An increase in pH can translate into greater availability of ionised hydrogen molecules, while a decrease translates into an increase in the availability of hydroxyl molecules (OH-​). These ions can react in different ways with various compounds –​ such as ammonium and calcium carbonate –​ and have significant impacts on crop performance. The optimum pH of most fish and aquatic organisms (particularly marine ones) is usually above 7, which is slightly more basic than acidic because haemolymph pH usually ranges between 7.5 to 8.5. 4.6  Dissolved particles and compounds The high densities of living organisms –​as compared to their natural environment –​combined with the application of inputs like food, treatments, minerals, vitamins, among other compounds, result in a complex medium with a large number of dissolved particles. Among them, two are of particular interest for aquaculture: nitrogenous compounds where ammonia and non-​ionised ammonia are found and calcium carbonate, which is of particular interest for the production of shell-​forming organisms like bivalve molluscs and crustaceans. 4.6.1  Nitrogen compounds

The greatest contribution of nitrogenous compounds in an aquaculture culture medium comes from the proteins found in the food of cultured organisms. In the case of animals, these proteins (along with other nutrients, such as lipids) enter into catabolic processes for subsequently obtaining glucan and other compounds that are used for energy, tissue growth, and other processes, such as the production and movement of neurotransmitters and hormones. In the case of algae, nitrogen (from various nitrogenous compounds, such as nitrites and nitrates) is used together with phosphorus as precursors for the metabolic processes responsible for obtaining energy and growth. Thus, the more food

Effects of the environment on aquaculture organisms  47 is provided and the less it is consumed, the greater the nitrogen availability in the water is, which in turn encourages algal growth (desired or unwanted). A nitrogenous compound is especially relevant in aquaculture production: ammonium ( NH +4 ), particularly the non-​ionised variant also called ammonia (NH3). In most animals, non-​ionised ammonia is a highly toxic compound. In the case of marine organisms, ammonia comes from ammonium, a compound generated after the catabolic process of proteins used for muscle development and energy production, and directly excreted into the medium through the gills. Furthermore, the decomposition of organic matter through certain bacterial metabolic mechanisms results in the expulsion of ammonia into the water column. Ionised ammonia can be considered practically harmless, but its chemical characteristics make it easy to react with water, giving rise to non-​ionised ammonia through the stoichiometric relationship. H 2 O + NH 3 ↔ NH 4+ + OH − As mentioned previously, the balance of this equation in water depends on the pH: a low pH means a higher concentration of ionised hydrogen, which favours the reaction with non-​ionised ammonium, giving rise to the less toxic form of ionised ammonium. As the pH increases, the equilibrium of the reaction shifts to the left, resulting in a higher ammonium concentration. At a temperature of 20°C, equilibrium is at a pH value slightly higher than 9. The balance of this reaction is also associated with ionic strength and temperature. Its relationship is directly proportional to the ammonia concentration in water, that is, as the temperature decreases, the equation shifts to the left, giving lower concentrations of ionised ammonium. Thus, the non-​toxic form of ammonium may appear in higher concentrations in tropical species, such as shrimp or tilapia, due to their metabolic requirements, which function optimally at higher temperatures. As a method for eliminating this compound, different approaches can be used depending on the production system and the species produced. In the case of species that support turbid waters with high concentrations of suspended particles, such as carp, tilapia, or shrimp, bacterial mixtures or bioremediants can be used, especially under Biofloc systems (in some media known as probiotics).6,7 Bioremediation metabolises ammonia to biomass and atmospheric nitrogen. In the case of species that require clear water, it is possible to opt for high exchange rates, as in trout production in meandering rivers or floating cages, which allow constant water flow. Another option is the use of biofilters, which follow the same principle as the use of bioremediation, but in a separate process from the organisms produced –​this system is particularly useful in RAS. 4.6.2  Calcium carbonate

The chemical concept that relates to mineral solution in water is known as hardness. According to this concept, water can be classified as soft if its mineral concentration

48  Daniel Peñalosa Martinell is low or hard if it is high. The compound used to estimate water hardness is calcium carbonate (CaCO3) or its equivalent amount. Calcium carbonate is an important compound for the development of various marine organisms, in particular for those that form shells, such as bivalve and gastropod molluscs, and for the formation of corals and exoskeleton of some crustaceans, such as crabs and lobsters. These organisms capture calcium carbonate from the medium for shell and exoskeleton growth. In the absence of this compound, organisms may show malformations, growth difficulties, various pathologies, and even death. Furthermore, carbonate is a significant buffer when it comes to extreme pH changes. To keep these functions optimal, producers tend to add alkalinity compounds to water, maintaining the buffering effect and minimising the consequences of water acidification. In the natural environment, the available calcium carbonate in water is related to calcium bicarbonate [Ca(CO3H)2] availability, mainly from the dissolution of limestone rocks and its hydroxylation by carbon dioxide (CO2), both atmospheric and the product of respiration of all living organisms. The chemical process involved in the passage of these compounds and their acid–​base equilibria is complex (see recommended readings: Turley et al. 2006 and Gattuso & Hansson, 2011 Chapters 1, 2 and 3 for deeper insights). However, as a summary, certainly before an increase in acidity (especially from CO2 concentration increase) a tendency to hydrolyse calcium carbonate takes place, giving rise to calcium and bicarbonate. This reaction is very important when the impact of climate change on some aquaculture organisms is evaluated, as discussed in Chapter 6. 4.7 Light As previously mentioned in the section on dissolved gases, water and its composition is not the only element in the natural environment that has a direct effect on farmed organisms. In addition to air and its responsibility in dissolving gases in the water column, light also plays a crucial role in the behaviour, growth, and development of aquaculture organisms. With respect to light it is important to remember that this concept is made up of different factors –​intensity, spectrum, photoperiod –​and each one of them can affect production performance in one way or another. Light affects living beings in different ways. It can function as an attractant/​ repellent through its relationship with photoreceptors, for example, in the larval stage of various individuals. In this sense, light directs the organisms towards the surface or depth, depending on the natural characteristics that favour their survival. This aspect can be used in crops to facilitate larval harvesting, making the process more efficient, and reducing costs and harvest times. In addition, light allows for locating prey, which is the source of energy that allows the survival of fed farm organisms.1 Light also plays a significant role in the pigmentation of fish and other aquatic animals. This aspect is not only relevant for the survival and proper development of organisms but also for their placement on the market and acceptance by consumers.

Effects of the environment on aquaculture organisms  49 The main mechanism by which light affects aquatic organisms is through a physiological concept known as circadian rhythms. Circadian rhythms are hormonal variations that plants and animals experience as a function of environmental stimuli –​mainly temperature and light-​dark cycles –​that allow regulating the behaviour of an organism and favour its survival. Living organisms depend on circadian rhythms or cycles to discern the time of year when it is most convenient to mate and when they must consolidate their hours of sleep and feeding. In some species, the variation of light and dark hours can accelerate or decelerate gonadal development, making reproductive control possible –​a key element to dominate seed production and thus species production. As previously mentioned, the presence or absence of light can be a significant element for animals to see their food and be more efficient when feeding. Thus, longer hours of light translate into better feeding rates, which translates into an increase in biomass in less time. 4.8  Effect of the presence of other organisms The physicochemical characteristics of water do not exclusively affect farmed organisms, but rather have a direct impact on all organisms living in water –​a concept dealt with in Chapter 5. In this manner, changes in water quality parameters can have a significant effect on production performance despite not affecting the critical points of reared species by promoting the growth of unwanted organisms, such as pathogenic bacteria and viruses, algae, and/​or parasites. In the case of closed systems, one of the main examples observed is lagoons or ponds. As discussed above, an inversely proportional relationship exists between temperature and dissolved oxygen. Thus, high temperatures favour the growth of microalgae (inhibited by high dissolved oxygen saturations). In addition, nitrogen compounds and phosphorus produced by farmed organisms and uneaten food provide an important source of nutrients to these microorganisms. The result is a phenomenon known as algal blooms, which is nothing other than intense reproduction of the algae present in the environment, which in extreme cases can cause system hypoxia and massive mortalities of farmed organisms. Another type of bloom corresponds to the appearance of red tides, which in the case of filter feeder production, such as bivalve molluscs, can have repercussions on human health. Algae and bivalves also represent a problem in floating cage systems, growing in the mesh and eliminating water flow efficiency. This unwanted growth is known as biofouling. The increase in temperature and reduction in water quality –​normally associated with a great dissolution of dissolved organic particles as a result of high densities –​ can favour bacterial growth and virus proliferation. In some cases, they can be pathogens for reared organisms and may result in growth reductions and, thus production inefficiency, malformations, and product quality loss, and even in massive mortalities and total loss of production cycles. Not only microorganisms and parasites can impact aquaculture production. The presence of natural predators near reared stocks can have a significant impact

50  Daniel Peñalosa Martinell on the performance of a farm. In some stages, insects are voracious predators of small organisms, such as shrimp post-​larvae reared in freshwater. In the case of freshwater tropical fish, organisms like amphibians and reptiles can be significant predators in the smolt and juvenile stages, and birds can feed on young and adult organisms of different kinds of fish and shellfish. Some mammals, like sea lions, can be a threat to large fish production, such as Chilean salmon.8 The presence of predators can be catastrophic in some cases and in different production stages. For example, they are considered a significant factor in mussel production seed loss in long lines,9 and birds can cause up to a 15% biomass loss in fish production.10 4.9  Suspended particles Unlike dissolved particles that react with water and its components, suspended particles correspond to organic or inorganic material that is suspended in water as food remains, bacterial flocs, or microplastics. Suspended particles can have a beneficial effect, such as the presence of controlled bioflocules2 that can be used as an alternative protein source in specific culture systems. They may also have negative effects such as causing gill blockages, making breathing difficult for the organisms and reducing their fitness, or the presence and intake of microplastics –​ anthropogenic pollutants significantly present in the oceans –​that have been shown to have negative effects on the physiology and behaviour of some fish.3 4.10  Meteorological phenomena Meteorological phenomena make up another aspect of the impacts that the environment has on aquaculture. Atmospheric events can have a significant impact on water quality, either through changes in salinity and pH associated with rainfall intensity or significant drought and evaporation or destruction of relevant production infrastructure caused by strong winds, hurricanes, or typhoons. It is a reality that meteorological phenomena have been increasing in number and strength over the last few years due to their relationship with climate change.11 Therefore, extreme events should be expected to increase and be a problem for aquaculture production (Chapter 6). As a solution to all environmental aspects that affect aquaculture production, one of the main production trends is to increase intensity while environmental control increases, for example, through inland recirculation systems. In addition to reducing the variability associated with environmental conditions, it is possible to maintain the productions closer to consumer markets, a factor discussed in the third unit of this book, which is very important when the profitability of an aquaculture project is assessed. The selection of the type of cultivation system has a direct relationship with water quality parameters and, in turn, is closely related to production sustainability, since the cultivation system and its infrastructure directly influence the environmental, social, and economic impacts that aquaculture production may have. The

Effects of the environment on aquaculture organisms  51 management of the facilities and control of water quality parameters to maximise the productivity of the farm can impact, for example, the type of employment that is produced, the impact it has on the environment, or the proximity to the markets. 4.11  Final remarks Understanding the reared species’ biological optimums in terms of water quality parameters is one key component in the success of an aquaculture endeavour. This will determine the site selection, the species selection, as well as the infrastructure development, the choice of genetic lines, and management strategies. Furthermore, since most aquaculture productions are carried out in the open, where the organisms are subject to changes in the weather conditions as well as the water’s physical and chemical composition, understanding and managing water quality is key for a successful aquaculture business. These changes, and the relationships that exist between all of them, will significantly affect the performance of the reared organisms. Maintaining adequate ranges for temperature, pH, salinity, oxygen, etc. will have a significant impact on the organism’s growth and survival. Also, they are associated with their tolerance to diseases and resistance to manipulation and management, aspects that will have a significant effect on production risks and, in turn, on the availability of financial products such as financial loans and insurance, an aspect that we’ll cover in Chapter 11. 4.12  Chapter review questions 1 What relationship exists between ammonia, pH, and temperature, and how does it affect aquaculture species? 2 What relationship exists between dissolved oxygen, temperature, and salinity? 3 Describe the osmotic regulation process in freshwater and marine fish. 4 How can light affect the performance of an aquaculture farm? 5 What effect does overfeeding have on water quality and how does this affect reared organisms? Recommended readings Boyd, C. E. & Tucker, C. S. (2012). Pond Aquaculture Water Quality Management. Springer. pp. 715. Boyd, C. E., & Tucker, C. S. (2014). Handbook for aquaculture water quality. Handbook for Aquaculture Water Quality, 439. USDA Agricultural Research Service. Deane, E. E., & Woo, N. (2009). Modulation of fish growth hormone levels by salinity, temperature, pollutants and aquaculture related stress: A review. Reviews in Fish Biology and Fisheries, 19(1), 97–​120. Gattuso, J. P., & Hansson, L. (Eds.). (2011). Ocean Acidification. Oxford university press. Lucas, J. S., Southgate P. C. & Tucker C. S. (2019). Aquaculture: Farming Aquatic Animals and Plants. 3rd edition. Wiley-​Blackwell, pp. 664.

52  Daniel Peñalosa Martinell Turley, C., Blackford, J., Widdicombe, S., Lowe, D., Nightingale, P. D., & Rees, A. P. (2006). Reviewing the impact of increased atmospheric CO2 on oceanic pH and the marine ecosystem. Avoiding Dangerous Climate Change, 8, 65–​70.

References 1 Langford, T. Ecological Effects of Thermal Discharges. Elsevier Science Publishing Co.: New York, 1990. 2 Dallas, H.. “Water temperature and riverine ecosystems: an overview of knowledge and approaches for assessing biotic responses, with special reference to South Africa.” Water SA 34.3 (2008): 393–​404. 3 Alfonso, S., M. Gesto, and B. Sadoul. “Temperature increase and its effects on fish stress physiology in the context of global warming.” Journal of Fish Biology 98.6 (2021): 1496–​1508. 4 Varriale, A., and G. Bernardi. “DNA methylation and body temperature in fishes.” Gene 385 (2006): 111–​121. 5 Sun, M., S. G. Hassan, and D. Li. “Models for estimating feed intake in aquaculture: a review.” Computers and Electronics in Agriculture 127 (2016): 425–​438. 6 Peñalosa-​Martinell, D., Vela-​Magaña, M., Ponce-​Díaz, G., and Padilla, M. E. A. Probiotics as environmental performance enhancers in the production of white shrimp (Penaeus vannamei) larvae. Aquaculture 514 (2020): 734491. 7 Helmy, Q., Kardena, E., and Gustiani, S. Probiotics and bioremediation. Edited by Miroslav Blumenberg, Mona Shaaban, and Abdelaziz Elgaml. In Microorganisms (pp. 153–​162). IntechOpen, London, UK, 2019. 8 Quiñones, R. A., et al. “Environmental issues in Chilean salmon farming: a review.” Reviews in Aquaculture 11.2 (2019): 375–​402. 9 South, P. M., Delorme, N. J., Skelton, B. M., Floerl, O., and Jeffs, A. G. (2022). The loss of seed mussels in longline aquaculture. Reviews in Aquaculture 14.1: 440–​455. 10 Otieno, N. E.. “Economic impact of predatory piscivorous birds on small-​scale aquaculture farms in Kenya.” Aquaculture Reports 15 (2019): 100220. 11 Bouwer, L. M. “Observed and projected impacts from extreme weather events: implications for loss and damage.” Loss and Damage from Climate Change: Concepts, Methods and Policy Options (2019): 63–​82.

5 Aquaculture’s effect on the environment Daniel Peñalosa Martinell

Aquaculture needs to keep growing to satisfy the increasing world population and its demand for seafood. As we have mentioned in previous chapters, this growth was impressive during the decades of the 1980s, 1990s, and 2000s, with double-​ digit annual growth rates; nonetheless, this growth came with a substantial environmental cost, mainly derived from a lack of knowledge on the potential impacts of the activity and the increased intensity of production. But not everything in aquaculture is a negative impact. Over the last decade, significant efforts have been made to improve the sustainability of the aquaculture industry. From new regulations to technological developments and management strategies, investments, and research have made it possible to keep growing while reducing the negative environmental impacts. Nowadays, aquaculture can be a successful production activity with some positive impacts on the environment, society, and the economy, although it is still in its infancy, there is a significant push from several of the industry’s stakeholders to grow sustainably. 5.1 Introduction Aquaculture, like most production processes, has a derived environmental impact, which should be evaluated and compared with the economic and social benefits obtained from production. Additionally, negative environmental impacts should be minimised for various reasons: 1 Environmental deterioration can have a significant effect on production due to the close relationship that exists between production and the environment (see Chapter 4). 2 Continual water, atmosphere, and land pollution can lead to climate change acceleration and, in extreme cases, produce an inhospitable planet. 3 If poorly managed, the effects of points 1 and 2 lead to an environmental trap, that is, a vicious cycle where more human intervention helps to isolate and control the environmental impacts on production. However, environmental deterioration increases, making a higher level of intervention needed to isolate DOI: 10.4324/9781003174271-7

54  Daniel Peñalosa Martinell environmental effects, increasing the environmental impact, and so on. For example, the most common way to control temperature in a shallow inland pond is to perform water exchanges. This type of control is usually done with electric or petrol motors, which are associated with greenhouse gas emissions. Their concentration is one of the most significant components of climate change, which results in an overall increase in the Earth’s temperature. Since temperature will be higher in the following cycles, the water exchange rate needs to increase, and so will the emissions of contaminant gases, accelerating climate change. The impact that aquaculture continues to have on the environment is diverse and closely linked to the production system and management strategy. In open systems, aquaculture is a classic case of an ecological trap. Unfortunately, wild populations are attracted to these systems because of certain production characteristics, such as infrastructure materials and greater food abundance. However, those same characteristics create inferior biological performance (lower reproduction, growth problems, higher disease prevalence) due to water quality deterioration around the productive areas (Figure 5.1).

Figure 5.1 Attraction and repulsion mechanisms that lead to an ecological trap. Art by Gonzalo Suinaga.

Aquaculture’s effect on the environment  55 On the other hand, productions in closed systems, such as recirculation, can control this effect by treating water and minimising effluents. Nevertheless, these treatments currently require much higher energy consumption than that observed in open productions. This result translates into greenhouse gas (GHG) emissions when fossil fuels are used as the main source of energy, resulting again in an environmental trap, as described in point 3 above. 5.2  Impacts on water quality High densities, feeding rates, and water treatments provided to maximise the productive performance of aquaculture farms are associated with an increase in particle concentration in the water column, both dissolved and suspended, as well as organic and inorganic. Depending on the infrastructure characteristics, management methods of the facilities, and current legal framework in the production area, the water used in production will be discharged to the natural environment in a greater or lesser proportion and with greater or lesser treatment. In general, open systems, whether inland or grown directly in a natural water body, have high turnover rates and do not have water treatment methods. This situation is especially true for crops grown on floating artifacts and at the mercy of water currents. In recirculation and zero discharge systems, the formation of sludge is especially important, with high concentrations of biological material that must be disposed of correctly to maximise the environmental benefits of the technology. Due to the complex relationships that exist between the different components of ecosystems affected by aquaculture, the impacts associated with water quality have direct effects on the biota, atmosphere, and land. The dissolved compounds in culture water that can have a greater impact on water quality in the natural environment can be classified as organic and inorganic particles. 5.2.1  Organic particles

Most aquaculture products (with the exception of the production of algae and filter organisms) require the external application of prepared feeds, which is especially true for high-​value species, associated mainly with carnivorous organisms (i.e. salmon, snook, shrimp, lobster). Since in no case is the food provided consumed in its entirety, this activity results in an increase of dissolved organic particles. Furthermore, excretion produced by the organisms also contributes to an increase in organic particles that can be dissolved in water. The uneaten food and excreta of the organisms transfer a large amount of nutrients to the environment surrounding the aquaculture production facilities, either by water exchange or directly through the floating cages and ponds. The impact of these discharges varies according to the quantity, concentration, and composition, which in turn depends on the scale, species, genetics, and technification of the production unit, as well as the capacity to assimilate the surplus nutrients from each zone. In addition to uneaten food and excreta, the produced organisms generate other organic compounds that can impact the environment due to the very high production

56  Daniel Peñalosa Martinell densities, particularly in open systems. For example, appendages, exuviae, and other biological components have the potential of decomposing. In the case of productions with bioflocules (also known as biofloc) that promote bacterial or algal growth, if no treatment is available in the discharges, carbon, nitrogen, and phosphorus output may be significant. The presence of these compounds can have significant effects on the proliferation of other organisms that use these compounds as nutrients for their development, such as algae. 5.2.2  Proliferation of primary organisms

As described in Chapter 4, the use of food with a high protein content results in the emission of effluents with high concentrations of nitrogen and phosphorus, both essential inputs for the metabolic processes of micro-​and macroalgae. In the case of microalgae, this process can lead to algal blooms, which is nothing more than an extreme proliferation of microalgae in a short period of time. After the proliferation and death of organisms, respiration processes and, mainly, the decomposition of organic matter result in a high rate of oxygen consumption, which can cause hypoxia and death of many organisms around the phenomenon. If this effect occurs in closed systems, it may result in massive mortality. In the case of macroalgae, growth is slower, but it can also show some difficulties. The main difficulty is the proliferation and growth around the production infrastructure, a process known as biofouling or simply fouling. This proliferation in the nets is mainly problematic in floating cage productions, since the organisms impede water flow, which increases the concentration of dissolved particles and reduces oxygenation. In addition, in systems found in the natural environment, the proliferation of algae (both micro-​ and macroscopic) is associated with that of their consumers. For example, either filter feeders, such as bivalve molluscs (also associated with fouling problems) or other organisms, in turn, can attract predators (that might have an impact on the cultivated organisms), increasing the population, reducing water quality and, again, giving rise to an ecological trap. 5.2.3  Inorganic particles

Besides the feed provided, faeces, and other organic waste associated with the maintenance of living organisms, aquaculture producers tend to use other additives to maximise yield and minimise production risks. Some of the additives used include antibiotics, disinfectants, compounds for water and soil treatment, algaecides, pesticides, and fertilisers. The most studied case with the greatest direct impact on human health is the use of antibiotics. Antibiotics are one of the most widely used compounds in aquaculture. They can come from natural or synthetic compounds, and their primary objective is to kill or inhibit bacterial growth, particularly those with pathogenic conditions. Several studies have shown that –​although the use of antibiotics can improve the productivity of a farm in the short term –​they have various associated risks and

Aquaculture’s effect on the environment  57 impacts on both human health and the environment. Antibiotics have been found to accumulate in the culture environment, sediments, and tissues of farm animals. In the case of open production systems (the majority around the world), antibiotics are dispersed in the natural environment through effluents. The presence of antibiotics in the natural environment can lead to the generation of resistance for different bacterial strains, which could lead to the creation of diseases that can prove to be extremely difficult or even impossible to treat with current methods. Despite a global reduction in antibiotics that has been observed associated with the use of technologies, such as vaccination or probiotics, their prophylactic use as a bactericidal treatment continues to be the preferred option in some countries. 5.3  Impacts on the atmosphere The main impact of aquaculture production on the atmosphere is associated with GHG emissions. Firstly, these gases come mainly from management, in particular feeding and energy consumption. Secondly, other aspects associated with some types of production such as soil removal, land use, or microorganism's metabolism can have an impact on GHG emissions. In 2017, an estimated 263 million MT of carbon equivalent were released to the environment from aquaculture (excluding algae production), of which 57% came from feeding (inputs, manufacturing, and transport), and the rest, a significant part, came from microorganism metabolism present in the pond. 5.3.1  Greenhouse gas products of energy consumption

GHGs are the main driver of climate change. As discussed in Chapter 6, these gases can be classified as anthropogenic –​produced by man –​and non-​anthropogenic –​ produced by nature –​depending on their origin. Most anthropogenic GHGs come from the combustion of fossil fuels, mainly used for power generation. The chemical reaction associated with the combustion of fossil fuels results in the production of ash and carbon dioxide or CO2. In addition, if combustion does not occur completely, other emitted gases can aggravate the greenhouse effect, mainly methane (CH4), nitrous oxide (N2O), other nitrogen oxides (NOx), sulphur dioxide (SO2), and volatile compounds other than methane. The energy dependence and amount of emissions associated with aquaculture production depend on the type of production (e.g. extensive/​intensive shrimp/​oyster farming). In general, the sector’s dependence on energy is clear –​ often coming from non-​renewable sources or directly from the burning of fossil fuels for the operation of generators in remote areas –​especially if all the energy components are considered in the production chain. For example, those associated with aquaculture range from the production/​collection of juveniles, food, farm operation, harvesting, processing, and marketing. One of the solutions that has been proposed to maintain aquaculture growth while minimising the impact on the natural environment, mainly associated with

58  Daniel Peñalosa Martinell water discharges, is to favour production in recirculation systems. These systems show an increase in rearing density, reduction in effluent emissions, impact minimisation of environmental variables, greater control over production, and as a result greater productivity per unit area. However, it is important to emphasise that these production systems are also associated with an increase in energy consumption. While the production of 1 kg of salmon in an open system has an estimated energy consumption of 1.3 kWh kg–​1, this estimate may rise to more than 80 kWh kg–​1 when produced in a recirculation system.1,2 However, some estimates establish energy consumption of 8.8 kWh for the production of smolts and an estimation from 6 to 10 kWh per kilogram produced in the grow-​out stage.1 Although the control derived from the use of RAS makes it possible to adapt production to climate change derived from GHG emissions, it can also be a relevant emission factor of using fossil fuels as the main source of energy. The impact that it has on the ocean, open productions, and, even more relevant, humanity is significant and must be considered when favouring production in recirculation systems. 5.3.2  Other greenhouse gas emissions associated with aquaculture

As mentioned earlier in this chapter, the single major component of GHG emissions from aquaculture is the use of commercial feed, which accounts for up to 57% of all emissions associated with aquaculture.6 The emissions generated by the production and sourcing of crop feed ingredients (up to 39% of the total emissions from the activity) are also included, the other 18% is attributed to sourcing of fishmeal and fish oil, as well as feed blending and transport. Another important source of GHG emissions, which is often not considered, is that generated by metabolism. This emission is either generated by the metabolism of the reared organisms or the decomposition of surplus food, which generates, in addition to CO2, significant amounts of methane (CH4), and nitrous oxide (N2O). Although uncertainty exists about the metric tonnes emitted to contextualise the relevance of this contamination source, as estimated in 2008 the aquaculture sector emitted 0.33% of the total anthropogenic N2O (0.09 MT). Thus, the projection is that by 2030 this proportion will have risen to 5.72% (0.6 MT).3 5.3.3  Estimating environmental impacts: a brief introduction to life cycle analysis

Estimating GHG emissions is not easy and requires a significant amount of assumptions and abstraction, mainly due to the difficulty in directly measuring the emissions of different kinds of gases and the efficiency of implementing existing instruments. Furthermore, different water quality components (like temperature, pH, or salinity, see Chapter 4) have an effect on the emissions generated by a pond or tank since there is high dependence on the metabolism of the organisms present in the water. That being said, some different methodologies are used to estimate the emissions of an industry or product, of which the most common one is the life cycle analysis (LCA). According to the European Committee for Standardisation, a life cycle analysis is a “method used to quantify environmental burdens based on inventory of

Aquaculture’s effect on the environment  59 environmental factorsi for a product, process or activity from the abstraction of raw materials to their final disposal”.1 With the LCA methodology, different environmental impacts generated by different activities can be standardised and estimated, including aquaculture. This methodology allows standardisation, which in turn helps decision-​makers and researchers to have a similar baseline to evaluate and compare the environmental impact of the studied activity. A complete description of the LCA methodology and its use in aquaculture is outside the scope of this book, however readers are encouraged to look into the recommended readings to deepen their understanding of the development and application of LCA.2 5.4  Impacts on land and high-​value ecosystems The impacts produced on land (or the marine mantle) are mainly associated with soil eutrophication and depletion of highly valuable ecosystems, such as mangroves or coral reefs that, in extreme situations, can have a devastating effect on coastal populations. The impacts of aquaculture on these areas largely depend on farmed organisms, the systems used, and existing regulations in the country of origin. In the case of productions in floating cages in the natural environment, like most salmon production, a significant impact has been observed on the seabed associated with faeces precipitation, uneaten food, and other organic and inorganic compounds. As a result, the areas below the floating cages lose biodiversity and, in extreme cases, make it impossible for organisms to grow –​sessile organisms are mainly affected. An important example of the deterioration and destruction of significant terrestrial ecosystems due to aquaculture practices is that of shrimp farming. Traditionally, the development of shrimp farming has been associated with loss of mangrove cover, especially in Southeast Asia. In 2001, approximately from 1 to 1.5 million ha of coastal lowlands have been converted into shrimp ponds, of which the main ecosystems affected are salt flats, mangrove areas, and marshes.4 However, this practice has been reduced by pressure from public opinion. Regardless of this practice, most of the shrimp produced by aquaculture comes from ponds built near the coastline, which has continued generating impacts on the coastal zone. In addition to the modification of the coastal zone, aquaculture alters trophic networks where uneaten food is used by fauna peripheral to the crop, modifying the structure of wild populations. It should be noted that although the discharges are few compared to the total organic discharges of anthropogenic origin, the impacts on aquaculture are localised and profound. Often, these impacts are detrimental to the activity itself since the quality of available water is reduced and the transmission of diseases between aquaculture production units and wild populations is promoted. 5.5  Impacts on wildlife Barret et al.3 proposed a series of categories to classify the impact of marine aquaculture on wildlife. The proposed categories are: abundance, diversity or richness in species, physiological changes, pollution, infection rates, and survival and

60  Daniel Peñalosa Martinell fertility. This categorisation can in turn be used to assess the impact of most aquaculture operations on biodiversity. In most cases, the impact is directly associated with a thermal change known as ecological traps. As mentioned at the beginning of this chapter, ecological traps can be defined as the attraction to a lower-​quality environment due mostly to feed and infrastructure. Surprisingly, many of these farm-​related environmental changes, such as light, noise, eutrophication, and high predator densities can be repellent to wary or functionally specialised taxa. 5.5.1 Abundance

In the cases of open-​water floating-​cage aquaculture, the effect of the feed provided means that, in most cases, the abundance of species that are found around a production area also increases. However, deterioration in water quality makes this increase in abundance a temporary effect that may have significant repercussions on the ecosystem where the production is located. In previous decades, the common practice to obtain seed from any aquaculture species consisted of capturing larvae and juveniles from the natural environment for later fattening. Then, this practice was found to have a significant effect on target species abundance, since elimination of complete wild species cohorts reduces or eliminates species recruitment, thus reducing its future reproduction possibilities. This effect is not only negative from an ecological point of view, but also socially, since it negatively impacts the fishing communities that depend on these species. This practice is still carried out, for example, in the process of catching and fattening tuna. However, restrictions and legislation that prevent capture below a certain size have been imposed, allowing the species to reproduce prior to capture. 5.5.2  Species richness (diversity)

Associated with the ecological trap concept, in most cases, aquaculture activities result in an increase in species diversity found in an area. On average the diversity increase has been estimated at 1.7 times with respect to the pre-​production status. In addition to increasing fish diversity and quantity, an increase in bird populations and diversity has been also observed. On the contrary, a decrease or negative impact on the population has been associated with species richness and diversity increase of fish and amphibian populations. Notably, studies carried out in this regard have dealt with a small number of target species, and the impacts have been observed exclusively on them. Despite species richness and abundance that have increased around the production areas, this effect may be detrimental to wild populations since water quality reduction takes place, increasing the possibility of pathogen transmission vectors. 5.5.3  Physiological changes

In the case of fish, those caught near aquaculture areas showed significant increases in size and weight compared to the same species captured in a control area. This

Aquaculture’s effect on the environment  61 result can be explained because a change in the diet of the organisms growing near aquaculture facilities allows wild organisms to feed on pellets provided by farmers for production. These dietary changes alter the fatty tissues of wild organisms due to differences in the fatty acid chains that are provided in the pelleted feed. 5.5.4  Pollution (biological)

A worldwide practice is the use of aquaculture as a source to replenish wild stocks by intentionally releasing larvae or juveniles of organisms of commercial interest. While some programmes have been successful, concerns have arisen that they may decrease genetic population variability, making them more vulnerable in the long term. Another risk is the escape of production organisms. Although they are native species in some cases, the organisms in production are often genetic lines selected for productive purposes (e.g. higher growth rate, resistance to diseases, increased tolerance to suboptimal conditions), so the transfer of these characteristics towards wild populations can significantly modify local communities. Despite the above, the clearest risk for diversity is the introduction of non-​native species, which are disease vectors attracted by the seed and reproductive trade or directly by the escapes of organisms from rearing farms. This situation can deteriorate native species and even eliminate them, when they become invasive species due to the absence of natural predators or better adaptation to the conditions of the new site. Several examples exist of exotic species that have adapted to the areas where they have been introduced, becoming invasive species with a significant impact on native ecosystems. Some of the most striking include the case of the bullfrog (Lithobates catesbeianus) brought from North America to South America, this species has become a predator of native species, and that of the red river crab (Procambarus clarkii) brought from North America to Europe, which is particularly problematic in Spain, where it has displaced various native crab species competing for food and space. On the other hand, introductions of new populations of the same species can lead to new diseases and parasites that can be lethal for native species because they have not developed defences. A very clear example is the Japanese oyster diseases introduced to North America, which have caused the reduction of native oyster stocks on the west coast of the United States. 5.5.5  Infection rates

The impact on disease and parasitism rates due to proximity to farms may be the primary concern for fish. For example, high population densities within farms create favourable conditions for disease and parasitism outbreaks, such as sea lice (Box 5.1ii). Wild fish populations can serve as reservoirs for parasites and diseases. They can also act as potent carriers of parasites and diseases as they travel between cages to take advantage of feeding opportunities.

62  Daniel Peñalosa Martinell Furthermore, the introduction of organisms of the same species imported from other ecological zones can be associated with the appearance of diseases. An example can be seen in shrimp productions, of which the most iconic case has been white spot virus. The appearance of this virus was first recorded in organisms produced in Asia. However, the wide connectivity and exchange of merchandise (such as reproducers, food, equipment, etc.) between Asian countries and the rest of the world allowed the introduction of this virus to the American continent, causing significant mortalities in countries such as Ecuador and Mexico. As discussed in Chapter 2, open facilities are characterised by discharging effluents into adjacent water bodies, which allow these vectors to escape into the environment, giving rise to the possibility of infecting wild organisms. 5.5.6  Survival and fertility

The effect of production on wild species survival is not well documented. Evidence of increases in fish population survival has been reported, as well as much higher mortality impacts for birds at some production sites. Although parasitisation and the pathogen increase observed in farms and cages are highly probable to have a negative effect on wild populations, the authors are not aware of the existence of studies that have demonstrated this effect in a conclusive way. In the same way as with survival, documentation regarding the effect of aquaculture productions on the fertility and reproduction of wild organisms is very sparse. The effect of the ecological trap is believed to be significant in this regard, increasing the presence of predators and reducing progeny survival. In addition, as mentioned in the previous chapter, water quality deterioration can have a significant effect on the reproductive capacity of many fish, mollusc, and crustacean species, so reproducers that live near farms could have a significant reduction in fertility and quality of eggs and hatchlings. 5.6  Potential ecologically beneficial outcomes from aquaculture As mentioned at the beginning of this chapter, impacts generated by aquaculture need to be observed and judged in a fair manner. Hence, this activity should also have the potential for ecologically beneficial outcomes. In this regard,4 a framework has been developed to standardise the measurement of such beneficial outcomes, separating them into 12 categories. 5.6.1  Biological control

Biological control consists in releasing a reared predator species in an area that can eliminate or reduce the presence of an invasive species or function as pest control.5 Although it can have a positive impact, its effects can be detrimental to other native species and there is a high risk of unbalancing the environmental structure.

Aquaculture’s effect on the environment  63 5.6.2  Species recovery

The strategy consists in breeding and releasing juveniles of targeted local species in danger or where natural stocks have been depleted by overfishing. The effectiveness of this activity remains controversial, particularly in finfish. The timing and methods for release have a significant effect on the probability of the restocked individual’s survival. This activity needs further research, although in some cases it has had significant social success. The release has seen significant positive impacts, particularly in closed or semi-​ closed water bodies, such as lakes or dams, where restocking of juveniles has helped maintain the fisheries sector in regions with a significant economic and social impact.6 5.6.3  Habitat restoration

With the use of reared organisms, restoring a degraded, damaged, or destroyed habitat structure and function partially or entirely is possible. To achieve this, the species produced needs to be considered an ecosystem engineeriii, it must be native to the area of production. Usually, though not exclusively, the aquaculture species that can promote this output are plants or invertebrates, of which coral restoration is one of the most significant cases of success.7 Other cases of habitat restoration are found in mangrove reforestation. Although mangrove is arguably not an aquaculture species (depending on the definition), its restoration can be coupled with classic aquaculture production, such as shrimp farming8 with the additional effect of carbon sequestration, another of the potential benefits. 5.6.4  Habitat protection

This term refers to the direct or indirect protection of a species or the structure and/​ or function of a habitat as a result of aquaculture. A good example is that the areas where aquaculture takes place can sometimes be considered as a type of marine protected area, since other activities, like fishing, in that specific area are forbidden. In this way, the species that live in the surrounding areas will be protected from direct, indirect, or bycatch from fishing activities. It is important to highlight that when a certain aquaculture activity has habitat protection characteristics, the degradation of the habitat where the activity takes place needs to be minimal. Hence, the farm needs to be careful not to have negative impacts on local species and reduce its footprint on the habitat itself. 5.6.5  Ex situ conservation

Ex situ conservation consists of rearing species outside of their natural habitat to increase control and reduce stressors or predators. This outcome is usually beneficial for a single species instead of having a positive full-​habitat effect. The objective

64  Daniel Peñalosa Martinell of this aquaculture is usually a conservation one instead of commercial, except for some cases where wild populations are lost or in danger.9 5.6.6  Wild harvest replacement

Wild harvest replacement consists in producing a species with commercial value to reduce the pressure that exists in that existing species’ natural stock. According to Tensen10 wild harvest replacement is considered a positive outcome as long as it meets a number of criteria: Products are indeed a substitute for wild products; demand is met but not increased (an increased demand would have an inverse effect, putting more pressure on wild stocks); legal production is cost-​ effective as opposed to black-​market products; there is no need to use wild stocks; and there is no transfer of products between legal and illegal markets which allow exploiting the wild stocks and laundering the illegal products. The best available examples for these outcomes come from ornamental aquaculture, especially freshwater ornamental aquaculture. In the case of marine water, production costs cannot compete with wild harvests in most cases, although new technologies and research have reduced those gaps with promising futures for species like the sea cucumber. 5.6.7  Habitat rehabilitation

Habitat rehabilitation consists in using native or non-​native species to improve a degraded ecosystem without fully recovering its original state. As opposed to habitat restoration, rehabilitation consists in the effect that aquaculture species or gear (such as ropes, nets, or others) have on a specific habitat. As mentioned previously in this chapter, this activity can result in an ecological trap, so its application and follow-​up must be studied carefully to avoid negative outcomes. Habitat rehabilitation may procure, as a side effect, an impact on habitat restoration. For example, if the produced organism has an impact on the environment, it may reduce invasive taxa biomass and increase native taxa biomass. 5.6.8  Removal of overabundant species

Removal of overabundant species is linked with capture-​based aquaculture and not with full closed-​cycle productions. This outcome consists in partially harvesting an overabundant species that does not have a market and moving them to an aquaculture facility to rear them until they have market value. For example, sea urchins can be removed to protect kelp cover and their further rearing until they have commercial value. The simple removal of species without further rearing is not considered within the scope of this classification due to its lack of an aquaculture component. 5.6.9  Coastal defence

Several natural biological structures serve as coastal defence mechanisms, reducing the strength of the waves and hence minimising the impacts on the shore and

Aquaculture’s effect on the environment  65 coastal communities. These natural structures, such as mangrove forests, coral and shellfish, or kelp mashes have been diminishing over the last decades due to deforestation, plagues, changes in water composition as a result of climate change, and other anthropogenic and non-​anthropogenic factors. Furthermore, climate change is responsible for an increased number and severity of meteorological phenomena, which can have a greater impact on the shore and coastal communities if these structures are not present. Through aquaculture, these structures can be replenished and recovered, although the methods used to do it need to be selected carefully so that the positive impacts expected do not harm the natural components currently present in the ecosystem. 5.6.10 Bioremediation

Aquaculture species, such as algae and some molluscs, can help in the water remediation process by removing excess nutrients from it. This process is particularly interesting in agricultural areas or other locations where aquaculture activities discharge water with high concentrations of nitrogen and phosphorus to the ocean. The reduction of extremely high nutrient quantities in water is a method to minimise the probability of having algal blooms that could potentially harm the local ecosystem or other aquaculture activities in the area. However, this strategy needs to be properly calculated to maintain a nutrient balance in the area. If the aquaculture project developed for bioremediation is too large, it can deplete the area of nutrients, which will have a negative effect on the surrounding environment due to a reduction of the availability of components in the base of the trophic system. 5.6.11  Assisted evolution

The rates at which many marine organisms evolve and adapt are being out-​paced by the rate at which their environment is changing11;12, these changes result in an inevitable loss and relocation of aquatic species that cannot adapt to their new surroundings. Through genetic selection and manipulation, aquaculture sciences can select the individuals of certain species of concern that have an increased capacity of surviving in their new environment. The most significant examples would be resistance to diseases or increased tolerance to environmental conditions, such as temperature increase, changes in pH, salinities, etc. 5.6.12  Climate change mitigation

Aquaculture helps to mitigate the anthropogenic components of climate change, reducing its speed and allowing more time for adaptation. The way through which aquaculture can help in climate change mitigation is through the promotion of species and techniques that contribute to a net sequestration of greenhouse gases, also known as blue carbon due to the aquatic nature of this type of carbon sequestration.

66  Daniel Peñalosa Martinell A great example of these activities is the promotion of macroalgae production since these species are very efficient in carbon sequestration and they also help mitigate other aspects associated with climate change, such as pH increase (hence reducing the effect of ocean acidification) and net oxygen production (oxygen reduction is associated with water temperature increases; Chapter 6). Although algae production looks promising, it also has some challenges, such as the production area13 To sort out the complexities related to the economic feasibility of these aquaculture activities, some interesting economic and financial tools have been developing over the last years, with the most promising being the creation of a blue carbon market that could help internalise the emission externalities and provide an extra financial incentive for production involving carbon sequestration. 5.7  Final remarks In this chapter, we have described both the negative and positive impacts of aquaculture on the environment. Although the negative impacts have been more studied and advertised, the positive effects of this activity could be significant and present great potential. Under-​regulation and lack of knowledge during the initial stages of the aquaculture industry’s growth resulted in increased pollution, mangrove deforestation, soil eutrophication, and water quality reduction. This has resulted not only in negative environmental impacts but also in social welfare reductions through the abandonment of farms, the disappearance of small farms, and the loss of jobs due to farm closure at regional levels. This opened the eyes of the industry stakeholders and led to an increase in regulation and research on improved and sustainable aquaculture production. All of the potential beneficial outcomes have a sound theoretical framework, and most of them are achievable under real-​life circumstances. As we’ve seen, some of them even have had successes, however, overall, there is little evidence of the significant ecological impact of these activities to date. The main problem behind some of these strategies lies in their economic feasibility and the self-​sustainability of the endeavour. An increased incentive to further implement these techniques at all levels of aquaculture production could be a solution to promote the adoption of these practices to a greater or lesser extent. 5.8  Chapter review questions 1 Which do you consider the most significant negative impacts of aquaculture on the environment? 2 Which is, in your opinion, the most significant potential ecological benefit of aquaculture? 3 What do you understand by life cycle analysis?

Aquaculture’s effect on the environment  67 4 How do you propose to minimise the negative environmental impacts of aquaculture? 5 Which do you think is the main constraint towards implementing environmental protection measures? Recommended readings Ahmed, N., & Turchini, G. M. (2021). Recirculating aquaculture systems (RAS): Environmental solution and climate change adaptation. Journal of Cleaner Production 297: 126604. Biermann, G., & Geist, J. (2019). “Life cycle assessment of common carp (Cyprinus carpio L.)–​A comparison of the environmental impacts of conventional and organic carp aquaculture in Germany.” Aquaculture 501: 404–​415. Bohnes, F. A. et al. (2019). “Life cycle assessments of aquaculture systems: A critical review of reported findings with recommendations for policy and system development.” Reviews in Aquaculture 11(4): 1061–​1079. Bohnes, F. A. & Laurent, A. (2019). “LCA of aquaculture systems: Methodological issues and potential improvements.” The International Journal of Life Cycle Assessment 24: 324–​337. Ciambrone, D. F. (1997). Environmental Life Cycle Analysis. CRC Press. De Silva, S. S., & Soto, D. (2009). Climate change and aquaculture: Potential impacts, adaptation and mitigation. Climate change implications for fisheries and aquaculture: Overview of current scientific knowledge. FAO Fisheries and Aquaculture Technical Paper, 530: 151–​212. Duarte, C. M., Bruhn, A., & Krause-​Jensen, D. (2022). A seaweed aquaculture imperative to meet global sustainability targets. Nature Sustainability, 5(3): 185–​193. Galappaththi, E. K., Ichien, S. T., Hyman, A. A., Aubrac, C. J., & Ford, J. D. (2020). Climate change adaptation in aquaculture. Reviews in Aquaculture, 12(4): 2160–​2176. Henriksson, P. J. G. et al. (2012) “Life cycle assessment of aquaculture systems—​A review of methodologies.” The International Journal of Life Cycle Assessment 17: 304–​313. Maulu, S., Hasimuna, O. J., Haambiya, L. H., Monde, C., Musuka, C. G., Makorwa, T. H., … & Nsekanabo, J. D. (2021). Climate change effects on aquaculture production: Sustainability implications, mitigation, and adaptations. Frontiers in Sustainable Food Systems, 5: 609097. Mizuta, D. D., Froehlich, H. E., & Wilson, J. R. (2023). The changing role and definitions of aquaculture for environmental purposes. Reviews in Aquaculture, 15(1): 130–​141. Pillay, T. V. R. (2008). Aquaculture and the Environment. John Wiley & Sons. Read, P., & Fernandes, T. (2003). Management of environmental impacts of marine aquaculture in Europe. Aquaculture, 226(1–​4): 139–​163. Sladonja, B., (2011). Aquaculture and the Environment —​A Shared Destiny. InTech, Rijeka, Croatia. Theuerkauf, S. J., Morris Jr, J. A., Waters, T. J., Wickliffe, L. C., Alleway, H. K., & Jones, R. C. (2019). A global spatial analysis reveals where marine aquaculture can benefit nature and people. PLoS One, 14(10): e0222282. Tom, A. P., Jayakumar, J. S., Biju, M., Somarajan, J., & Ibrahim, M. A. (2021). Aquaculture wastewater treatment technologies and their sustainability: A review. Energy Nexus, 4: 100022.

68  Daniel Peñalosa Martinell Box 5.1  Reducing caligidosis impact in the salmon industry: A major factor in competitiveness where only an integrated control programme is effective, a lesson for Chilean Industry Jean Paul Lhorente Caussade –​Technical and Breeding Manager Benchmark Genetics, USS (United States Ship) Sea lice is one of the most important health problems in the Chilean salmon industry producing estimated economic losses of from USD 170 to 200 M. Although they do not usually cause mortality, they cause stress, loss of appetite, skin damage, and mainly a depression of the immune system that significantly increases susceptibility to other pathogens. Chilean sea lice are Caligus rogercresseyi, a native crustacean parasite that has been found from the beginning of the salmon industry in the late 1980s. This parasite has become a problem since the industry grew in produced biomass and is found in sea farming sites. Primarily, the main control tool was using authorized chemical products by feeding or bath applications. Initially these products were effective, but their uncontrolled use in an increasingly intensive industry produced parasite resistance resulting in all chemicals losing their effectiveness. In 2007, the high sea louse abundancy recorded was >50 parasite/​fish, which shows the parasite was uncontrolled. In addition, the high occurrence of caligidosis, the main bacterial disease of salmonid rickettsial syndrome caused by P. salmonis, generated the highest mortality in salmon farming (up to 20% mortality by sea site). Within a sanitary and sector crisis, salmon production depressed from 320 to less than 150 TMT from 2007 to 2009, the national sanitary authority (SEMAPESCA) together with the Chilean salmon industry decided to implement a programme of farming management areas. This programme consisted of farming density reduction, production compartmentalisation, and farming time limitation. Furthermore, experience has shown that it is not possible to bet on just one solution, so other factors should be improved integrally, e.g. host resistance, environment, and management practices. In these different lines, several suppliers have made efforts in the area of research and development: (1) feed companies have tested different additives that confer immune response enhancers through feed; (2) pharmaceutical companies work to generate effective vaccines and new effective chemical treatments; (3) egg suppliers (genetic houses) are producing improved eggs that have their own resistance to the parasite, and (4) bath suppliers work to develop new systems and well-​boats to make baths less stressful and effective. This example was a lesson for Chilean industry on how a transversal key factor such as caligidosis must be treated in a coordinated way with the authority and neighbours. Moreover, it requires analysing and planning production considering an epidemiological view, all the factors and resources and tools available to minimise the caligidosis risk to improve the industry sustainability.

Aquaculture’s effect on the environment  69 Notes i A Life Cycle Inventory (LCZ) is an objective data-​based process of quantifying energy and raw material requirements, air emissions, water borne effluents, solid waste, and other environmental releases incurred throughout the life cycle of a product, process or activity. ii BOX 5.1: Reducing Caligidosis impact in Salmon industry; A major factor in competitiveness where only an integrated control program is effective, a lesson for Chilean Industry. (Case study). iii (species that alter the physical condition of biotic or abiotic materials to affect the availability of resources (other than themselves) to other species, and in doing so, modify, maintain, or create habitats)

References 1 Arntzen, N. A. (2020). “Current and Future Energy Use for Atlantic Salmon Farming in Recirculating Aquaculture Systems in Norway” Master’s thesis in Energy and Environmental Engineering, Norwegian University of Science and Technology. 2 Kirkpatrick, N. (1992). Life cycle analysis and eco labelling, Sections: Life cycle analysis vs. life cycle assessment, Scope and Functional units, Presentation of results. PIRA International, Randalls road, Leatherhead, Surrey, UK. 3 Barrett, L. T., S. E. Swearer, and T. Dempster. (2019). “Impacts of marine and freshwater aquaculture on wildlife: a global meta-​analysis.” Reviews in Aquaculture 11(4), 1022–​1044. 4 Overton, K., T. Dempster, S. E. Swearer, R. L. Morris, and L. T. Barrett. (2023). “Achieving conservation and restoration outcomes through ecologically beneficial aquaculture.” Conservation Biology, e14065. https://doi.org/10.1111/cobi.14065 5 Barton, J. A., C. Humphrey, D. G. Bourne, and K. S. Hutson. (2020). Biological controls to manage Acropora-​eating flatworms in coral aquaculture. Aquaculture Environment Interactions, 12, 61–​66. 6 Soto, D., P. White, T. Dempster, S. De Silva, A. Flores, Y. Karakassis, ... and R. Wiefels. (2012). Addressing aquaculture-​fisheries interactions through the implementation of the ecosystem approach to aquaculture (EAA). Farming the Waters for People and Food, 385. 7 McLeod, I. M., M. Y. Hein, R. Babcock, L. Bay, D. G. Bourne, N. Cook, ... and L. Boström-​Einarsson. (2022). Coral restoration and adaptation in Australia: the first five years. Plos one, 17(11), e0273325. 8 Ahmed, N., S. Thompson, and M. Glaser. (2018). Integrated mangrove-​shrimp cultivation: potential for blue carbon sequestration. Ambio, 47, 441–​452. 9 Juarez, L. M., P. A. Konietzko, and M. H. Schwarz. (2016). Totoaba aquaculture and conservation: hope for an endangered fish from Mexico’s Sea of Cortez. World Aquaculture, 47(4), 30–​38. 10 Tensen, L. (2016). Under what circumstances can wildlife farming benefit species conservation? Global Ecology and Conservation, 6, 286–​298. https://​doi.org/​10.1016/​ j.gecco.2016.03.007 11 Filbee-​Dexter, K., and A. Smajdor. (2019). “Ethics of assisted evolution in marine conservation.” Frontiers in Marine Science, 6, 20.

70  Daniel Peñalosa Martinell 12 Deutsch, C., et al. (2015). “Climate change tightens a metabolic constraint on marine habitats.” Science, 348(6239), 1132–​1135. 13 Costa-​Pierce, B. A., and T. Chopin. (2021). “The hype, fantasies and realities of aquaculture development globally and in its new geographies.” World Aquaculture, 52(2), 23–​35.

6 Aquaculture and climate change Francisco J. Vergara-​Solana, Fernando Aranceta Garza, and Daniel Peñalosa Martinell

Aquaculture production is intricately intertwined with the environment. Just as in agriculture, the success of production areas and farm operations hinges significantly on the prevailing climatic conditions in those regions. However, it’s important to note, as highlighted in the preceding chapter, that farms, irrespective of their size and level of intensification, also exert an environmental footprint (e.g. emission of greenhouse gases, discharge of water with concentrated nutrients). With this background, in this chapter we delve into how the climate change –​ changes in global weather patterns –​can affect aquaculture; and also how the environmental impacts of aquaculture can amplify the risks associated with climate change. Climate change is not limited to temperature increases; it is a complex phenomenon that can have various effects, including ocean acidification, more frequent red tides, and an increase in severe climate meteorological events. Some of these effects can have physical, chemical, and biological impacts, while others can increase aquaculture risks, such as power outages, damaged infrastructure, and the escape of non-​native species. It is essential to recognise that not all changes related to climate change are negative, and in many cases, they can have positive effects. This chapter describes some of the impacts of climate change on the main aquaculture species and strategies that can promote aquaculture adaptation and mitigation of the negative effects while capitalising on the positive ones. 6.1 Introduction Estimations predict that, by 2030, aquaculture production will have increased by 20 Mt to meet the future demand for food. This situation implies an immense challenge, not only because the current food production growth rate is insufficient to achieve this goal but also due to restrictions based on limited land availability and adequate water for production, added to the environmental impact of current technologies. Furthermore, it is necessary not to lose sight that it must be achieved in an uncertain climate environment. In this sense and to overcome the problems DOI: 10.4324/9781003174271-8

72  Francisco J. Vergara-Solana et al. that production growth implies in the context of climate change, evidently the sector has to minimise its impacts. The most relevant are the depletion of ecologically important areas, pollutant emission in effluents, greenhouse gas emissions associated with energy consumption, and use of wild organisms as food and seed for some species of aquaculture production, to name just a few. However, reducing the negative impacts of the aquaculture industry must be complemented with adaptation and mitigation measures of uncertainties and risks associated with climate change and, of course, those effects of climate change that may become favourable and must also be capitalised on. 6.2  Impacts of climate change on aquaculture production systems Speaking of climate change (CC) (i.e. changes in global weather patterns), almost immediately the term is associated with temperature increase. However, the effects of climate change due to the intricacies of the ocean–​atmosphere relationship are diverse and multifactorial.1 The effects could, on the one hand, be considered as those changes in the “normal” physicochemical parameters of the ocean and the atmosphere. In turn, on the other hand, the effects derive from changes in meteorological, oceanographic, and ecological patterns (e.g. increases in harmful algal blooms, changes in the distribution and abundance of fish stocks). Among the physicochemical parameters commonly associated with CC are air temperature and sea surface temperature (SST), changes in the pH of the oceans due to carbon dioxide dissolution, and dissolved oxygen availability. However, also, changes in the normal climate, meteorological, oceanographic, and ecological patterns highlight sea level rise, wind intensity, and water column stratification; modification of precipitation, upwelling patterns, and primary productivity of the ocean; formation of hypoxic zones and increase in intensity and frequency of algal blooms, storms, and hurricanes; as well as alterations in the distribution and intensity of disease and parasite outbreaks. These CC impacts are those that are commonly described, but much still needs to be learned about them. In this sense, CC and its relationship with aquaculture have implications beyond the risks associated with changes in intensity and frequency of severe storms (especially for aquaculture in tropical areas) or physiological changes in growing organisms caused by changes in temperature, which in turn modify the available areas for production. Nevertheless, we must explicitly recognise that there is, overall, much uncertainty around the potential climate change impacts. In addition to the ecological, environmental, meteorological, and geographical impacts described, social factors associated with CC can impact the aquaculture industry, such as migrations of people from the tropics to temperate climates. This situation would play a significant role in the distribution, quality, and quantity of work and wealth production in each country, radically changing the current panorama. However, studies that relate CC to society and its relationship with aquaculture production are few, which creates an information gap.

Aquaculture and climate change  73 The information gaps concerning CC impact on aquaculture are largely due to the fact that making specific predictions and recommendations is complex, and impacts vary according to the species, specific locality, and the production system.2 Taking this into account, some of the recognised impacts that CC has in the context of aquaculture by a taxonomic group are described below in general, clarifying that these impacts can be positive in specific cases. To better understand how environmental changes affect organisms in production, Chapter 4 should be considered. Along the same lines, Chapter 10 explores how CC impacts can be formally included in risk assessments to improve decision-​making in aquaculture production units. 6.2.1 Crustaceans

The bulk of crustacean aquaculture production is represented by penaeid shrimp produced in tropical and subtropical areas. Production generally takes place in semi-​intensive ponds in coastal floodplain areas. These organisms are sensitive to increases in (a) sea surface temperature; (b) sea level; (c) rainfall; (d) diseases; and € hurricanes. These organisms are euryhaline species with tropical affinity. However, when their thermal tolerance limit is exceeded, they show (a) loss of appetite and reduce their growth rate; and (b) immunosuppression with vulnerability to bacterial infections (vibriosis) or viruses, such as the white spot or Taura syndrome, all generating massive mortalities and huge financial losses. In parallel, due to their location, cultures are vulnerable to storms, hurricanes, and high rainfall, affecting them mainly due to changes in salinity, osmotic over-​regulation, and low growth; escape of organisms; eutrophication with algal blooms and anoxia by agrochemicals; and expensive damage to infrastructure, such as power lines, roads, and constructions of the shrimp farming systems. Furthermore, marine acidification has been considered to possibly affect larval development in laboratories and growth. This effect could be increased in cultures with high densities due to increases in ammonia and CO2.3,4 6.2.2  Marine fish

Marine fish aquaculture in floating cages is represented by species diversity with different thermal affinities, for example, salmon in cold zones, sea bream or capture-​based aquaculture of bluefin tuna in temperate zones, or red snapper and cobia in tropical areas. A change in sea surface temperature would translate into a change in the distribution of the potential areas to produce each of the species. Regardless of the above, the floating cage production system entails practically no control over the conditions of the culture medium (e.g. in some cases, the cages could possibly be submerged to find optimal temperatures or mitigate the impacts of severe meteorological phenomena). In general, with a thermal increase, these species may frequently show skin and gill damage, and an increase in infections and parasites. The effect of marine acidification on marine fish is not likely to have

74  Francisco J. Vergara-Solana et al. a severe impact since fin fish have an acid–​base regulation system. However, it may cause an increase in metabolism, oxygen demand, and the risk of reduced production due to an increase in the frequency of red tides.5 6.2.3  Freshwater fish

Inland aquaculture is based on fish rearing in ponds or other bodies of water, such as shallow ponds or dams. These types of cultures are particularly vulnerable to factors such as thermal increases, floods/​rainfall, hypoxia, and infections. In inland tilapia cultures, a rise in the water temperature can cause stratification of the water column, besides the formation of anoxic zones and a propensity towards states of immunosuppression and infections with low growth rates and even mortalities. These effects can be exacerbated in coastal/​floodable areas due to the fertilisation of water bodies caused by rainwater transport of agrochemicals, which can generate intoxication by algal blooms or cause osmotic stress due to seawater intrusion (due to sea level rise or severe storms) (which can also increase the risk of invasive species escapees). In addition to the above, the occurrence of hurricanes causes escapes and/​or massive mortalities of individuals, along with losses in facilities and infrastructure. On the other hand, cultures of temperate species are expected to show a contraction in the potential production areas as temperature increases with a displacement of the areas suitable for production to higher latitudes. 6.2.4  Bivalve molluscs

Global bivalve production is mainly vulnerable to marine acidification due to the dependence on their calcareous structures (i.e. shells). Some global effects that have been reported on farmed individuals include a reduction in growth, and thickness and length of their valves; larval stage abnormalities; and affectations in the reproductive process.6 This last factor impacts farmed oyster species mainly, such as the Japanese oyster (Crassostrea gigas) by reducing seed production in laboratories or survival of seedlings for stocking. In addition to acidification, the parallel thermal increase has caused episodes of massive mortalities in rearing C. gigas and infections by protozoa.7 For other aquaculture molluscs with subtropical–​temperate affinities, such as the blue abalone, Haliotis fulgens, climate warming negatively impacts their food; the laminar macroalgae (Macrocistis pyrifera and Eisenia arborea) directly affect the production line of farmed juveniles as they increase mortality and recruitment, although the growth rate can increase. Likewise, the cultured comb clams (Peneidae) have shown a predisposition to immunosuppression. In the case of geoducks, only in the settlement phase are they susceptible to high temperatures, anticipating a potential contraction in their distribution, affecting the collection of reproducers, and reducing the area available for their production. In the case of species with tropical affinity, such as the pen shell, Atrina maura, the thermal increase has caused a higher prevalence and levels of infection by Perkinsus sp. and negative changes in spawning and production of stressed oocytes, decreasing reproductive success.

Aquaculture and climate change  75 6.2.5 Macroalgae

Climate change’s impact on the production of macroalgae depends on the thermal affinity of each species in production. It is important to note that these species are usually sensitive to temperature, so a change in area distribution and potential species is expected for production.8 In addition, slight changes in pH or salinity of the production systems can translate into changes in growth (slower or faster depending on the species) or competitive exclusion by algal species more suitable to the new sea conditions; in a situation with invasive species, native species can be displaced. Furthermore, most of the production of macroalgae is performed submerged with relatively less workforce and infrastructure and they also do not require exogenous feeding. Together, these features reduce the risks of CC impacts, but in vulnerable communities, even a small impact can have profound repercussions. 6.3  Mitigation of the activity impacts and negative effects of climate change Although aquaculture can be impacted by the effects of CC in general, it can also create negative externalities (i.e. unaccounted-​for impacts) that translate into general environmental deterioration. These impacts may have implications in the context of CC (e.g. greenhouse gas emissions). Chapter 4 provides more information on the impacts that aquaculture can have on the environment. To date, there remains uncertainty about how exactly CC impacts will affect the aquaculture sector and its scope on production, and how the environmental impacts of aquaculture can exacerbate the adverse effects of CC. Regardless of this situation, the sector should also generate strategies to mitigate the possible effects of these impacts.9 The purpose of mitigation is to make this potential damage less severe. The treatment of all these factors has a direct impact on production profitability and risk reduction. If impacts are treated improperly, they can lead to insolvency, destroying the livelihoods of many people and putting food security at risk. Impact mitigation can be approached from different perspectives, mainly from the public sector, the perspective of the private initiative, or through market mechanisms. The first one seeks to encourage or discourage the impacts of the industry, mainly through the use of public policies, such as subsidies, taxes, fines, imposition of production quotas, prohibition, or permits. The private initiative can mitigate its impact through the use of new technologies and management techniques. Finally, the consumer can promote attenuating impacts through a preference for environmentally responsible products, forcing competition to improve their practices to compete in the markets. 6.3.1  Public sector strategies to mitigate impacts

The state can intervene in several ways to mitigate the impact of climate change on the aquaculture sector, as well as to reduce the negative impacts of production.

76  Francisco J. Vergara-Solana et al. 6.3.1.1  Production zoning

One of the main activities that the government can carry out to promote sustainable aquaculture is the application of spatial planning or a zoning programme. The state may give preference to certain species depending on the production area, from the perspective of the species’ climate preference. For example, the production of temperate species in climate transition zones has the risk of losses (and what it entails from the social perspective) both through the effect of the interannual temperature variability (for example, in one year) and a long-​term trend of an increase in sea surface temperatures. In this line, the government can limit the use of land for aquaculture purposes in risk areas (e.g. floods, landslides) through land use planning to try to reduce the negative impacts of severe weather events.10 6.3.1.2  Production quotas

Another possibility to reduce both aquaculture impacts and the risks associated with CC is through the establishment of production quotas. For this purpose, the effect of aquaculture production needs to be established per unit or the amount of production that can be installed in an area (carrying capacity under current and expected environmental conditions) should be defined. Furthermore, a mitigation objective should be established, i.e. a maximum production by species, only providing permits to a limited number of concessionaires without exceeding the target production based on the previously estimated quantity. However, this type of tool can have a negative impact on food safety and even on the activity’s profitability, since production would be less than what could potentially be achieved in a given area.11 6.3.1.3  Taxes, fines, and subsidies

The most used tools for regulating economic activity are the use of taxes, fines, and subsidies.12 For this purpose, the state must develop an impact analysis of the activity and set mitigation objectives –​ for example, reduce CO2 emissions –​ and establish fines and taxes that discourage excessive emissions by the industry. Various ways of applying these tools can be found, the most common is the use of Pigouvian taxes, that is, where the value of the tax is based on the pollutants emitted. On the other hand, the state can reward or encourage the use of mitigation tools, such as the use of technologies that reduce GHG emissions that also allow keeping the farm working in case of a power outage by subsidising companies that implement these types of elements. 6.4  The mitigation of impacts from the private sector Just like the public sector, private initiatives show a great variety of technologies and management techniques that can reduce the impact of production. Some examples are described below.

Aquaculture and climate change  77 6.4.1  Use of clean technologies

One of the technologies that allow the control of the variables affected by climate change effects is the recirculating aquaculture system (RAS). This method makes it possible to maximise the production yield per m2 by controlling water quality. Since production is more controlled, the emission of effluents and the effects of the surrounding environment on the production system are reduced. Additionally, water consumption is significantly reduced by reducing the water footprint of the activity. However, energy consumption grows, as it requires the continuous pumping of water, oxygen, and, in some cases, thermal regulation of water to maintain optimal growing conditions. In recent years, applied science has developed a large number of tools that allow for minimising the negative impacts of aquaculture production. The main one is the use of so-​called clean energies (photovoltaic, wind, geothermal, etc.), which allow the use of energy with minimal or no GHG emissions. Another example is the use of the so-​called “zero discharge” technologies, that is, they eliminate or significantly reduce the need for water changes.13 An example of these technologies is the use of probiotics and bio-​remediators, which allow not only maintaining a culture for a prolonged period of time without the need to use antibiotics or make water changes, significantly reducing GHG emissions, but also allowing economically competitive aquaculture farms in areas with a lower risk of CC impact (e.g., urban aquaculture facilities). 6.4.2  Multitrophic aquaculture

While the application of clean technologies is an important basis for any type of aquaculture, it is not the only solution to the environmental impacts in this field. Today, the vast majority of aquaculture production in the world is based on monospecific production, that is, the production of a single species. Multitrophic aquaculture or integrated multitrophic aquaculture is based on promoting the production of two or more species that benefit each other. For example, cage fish culture entails the emission of nutrients that can be used as food by some species of biofilter molluscs that, in turn, produce nutrients by excretion, which can be used by species of macroalgae capable of assimilating these nutrients and converting them into biomass (Figure 6.1). This type of production would entail minimum energy consumption and multiply the biomass obtained per unit of input used.14 A special variation of integrated multitrophic aquaculture is aquaponics, which is the combination of two productive techniques: aquaculture and hydroponics. Although this type of production is technically possible, it has not been proven to be economically viable on a large scale yet due to the complexity of the relationships between the organisms, technical difficulties, and the necessary investment to achieve an efficient production unit. However, proper planning and management could result in viable production. Nonetheless, this productive strategy has the potential to reduce inputs and aquaculture contamination, and

78  Francisco J. Vergara-Solana et al.

Figure 6.1 Integrated multitrophic aquaculture production scheme. The grey arrows refer to each phase inputs; the green arrows are each phase surplus; rectangles represent production units. The surplus of one phase serves as the input for the next one and is dosed by means of the current or water flux, represented by the curved blue arrow (Chopin et al., 2012).

at the same time, a more resilient production system by having more diversified production. 6.4.3  Optimisation of the operation of aquaculture production units

Finally, a tool of interest for mitigation by the private industry consists of optimising the infrastructure and available inputs. Data science and business analytics are examples of management tools that allow for minimising production impact, maximising biological and/​or economic performance, and reducing risk through proper decision-​making. These tools are based on the use of mathematical and statistical models capable of predicting production behaviour based on the information provided by the production area. Models have traditionally been used to optimise the economic performance of companies; however, they can be applied to a variety of fields, thus directing research and industrial production towards sustainable development goals. The use of bio-​econometric models can be useful for various analyses to estimate how decision-​making can affect production, job creation, environmental impact, profits, and industry competitiveness.15 Furthermore, this analysis can also be applied to assess the risk of uncertain climate scenarios, so they can be a powerful tool to design strategies and mitigate climate change adverse effects. The application of these tools can be seen in the case study in Section 6.7.

Aquaculture and climate change  79 6.5  Market strength as an incentive to reduce the impacts of the activity Finally, some market mechanisms exist that can act as an element of pressure on producers to direct them towards more responsible production with the environment; thus, the impacts of the activity on climate change are mitigated (and they could potentially work to incentivise more resilient aquaculture). Some examples of market incentives are described below. 6.5.1  Consumer power and eco-​labelling

The principle of consumer power is based on the impact that purchasing preference has on the market. To ensure that a company has a responsible production system with the environment, a production evaluation system should be certified by an independent third party that authenticates the company’s commitment to sustainable production through the use of indicators and audits –​both internal and external. Once the certificate is obtained, the products can be labelled as sustainable, giving information to the consumer regarding production practices, and positioning the product on the market as responsible for the environment. Some examples of this are the ISO 14001 certificate, Fair Trade, Best Aquaculture Practices (BAP), or the Aquaculture Stewardship Council label. More and more consumers prefer purchasing responsible products for the environment, and also from markets that condition purchases on certified products (e.g. sustainable sourcing commitments of major retailers) encouraging companies to carry out responsible production to compete in the market. 6.5.2  Establishment of carbon markets

This tool combines the influence of the state, private initiatives, and the market. Its principle is based on the free market and the establishment of a CO2 emissions target for the industry known as the emission quota. Once established, a carbon bond distribution is made. This distribution can be based on the size of the company, its production, or through an auction of emission bonds. Once the bonds have been distributed, companies can trade them based on their activity. If a certain company has a CO2 emission higher than that recorded in its bonds, it must pay a fine previously established by the state –​a fine that is destined to be used in mitigation projects (e.g. reforestation). In this way, companies have to reduce their emissions and try to maximise their profits by selling bonds to companies unable to reduce their impact.16 6.6  Adaptation mechanisms to climate change Two ways to face the global challenge posed by climate change are mitigation of the impacts that productive activity has on the environment, described in depth in the previous section, and adaptation to new climate conditions that may be experienced as a consequence of climate change.

80  Francisco J. Vergara-Solana et al.

Figure 6.2 Description of the time scale, benefits, efforts, and costs associated with the implementation of the different types of adaptation measures to climate change. The circle diameter represents the difficulty of implementing each type of adaptation. For the specific answers, the scale is usually of a productive cycle and has an associated cost reduction. In the case of planned adaptation, long-​term adaptation can span a much larger time scale, even generational (Barange et al., 2018).

In specialised literature, one can speak of different types of adaptation. For example, autonomous if the adaptation occurs spontaneously or planned if it is based on the analysis of historical series and climate projections to adapt production methods (Figure 6.2).17 Adaptation is also differentiated as a function of time. Short-​term adaptation is a quick solution to a climate change problem that will undoubtedly increase, or adaptation can be long term when its adaptation method consists of gradually adapting to a problem that will increase and the results will not be found for a period of about 10 years or more. Adaptation includes a variety of policies and actions, specific technical support, and community capacity-​building activities that address multiple sectors and may not be exclusively directed to the aquaculture sector (see Box 6.1). Having said the above, the first step towards adaptation consists of generating knowledge regarding the expected impact of climate change on the aquaculture sector; subsequently, risk must be evaluated where climate change impacts entail little risk to the species produced and could be unnecessary to carry out any adaptation method. On the other hand, if the changes associated with climate change have a significant impact on the species produced, it will be necessary to adapt to the expected changes. Once the impacts have been identified, the possible adaptation solutions should be evaluated. These solutions are shown at different scales, such as (a) individual; (b) sectoral; (c) state/​national; and (d) international. These scales are further defined in Chapter 16.

Aquaculture and climate change  81 In addition to those mentioned, many forms of adaptation to climate change exist depending on the expected effect on the species to be produced, facilities, productive areas, cohesion of the different stakeholders, and existing alliances. With this in mind, an agenda developed for adaptation to climate change in aquaculture at the national level should, as a minimum: 1 Be planned and consider the short-​, medium-​, and long-​term impacts, which include the projection of scenarios and species and impact evaluation. Society must rely on science to develop this point. 2 Take into account the different actors in the sector: suppliers, producers, communities, intermediaries, points of sale, government, and society in general. 3 Have a coherent government programme through the development of normative, legal, and executive frameworks that allow articulating the interactions of the different actors in a fair way. 6.7  An example of the possible impacts of climate change on bioeconomic indicators and its application for decision-​making under an uncertain climate context One of the main consequences of climate change (CC) is the increase in sea temperature. This phenomenon has different associated consequences that must be properly evaluated. In the case of the white shrimp Litopenaues [Penaeus] vannamei, water temperature plays a crucial role. This species has demonstrated a wide tolerance to different temperature ranges, showing a maximum lethal temperature from 35°C to 42°C and greater growth in temperatures from 22°C to 30°C. Thus, an increase in sea temperature would have a positive impact on the organism’s growth and a negative impact on its survival. In Mexico, most of the facilities are semi-​intensive or intensive cultures with stocking densities ranging from 10 to 300 post-​larvae per m2, with aeration systems and feeding using specialised feed. More than 98% of the shrimp farmed in Mexico comes from the northwestern coasts. In this area, differences can be found in SST. On the one hand, areas have shown an average temperate temperature and significant variations throughout the year. On the other hand, semi-​ tropical climates can be found with high average temperatures and small seasonal variations. With this in mind, this hypothetical exercise aims to answer the questions: What is the effect of sea temperature increase –​derived from climate change –​on white shrimp production in Mexico and what does it represent for the public sector and private initiative? For this exercise, two cultures in semi-​intensive, open systems should be added, with identical infrastructure for farming, but located in two potential productive zones within the Gulf of California. The first zone has a temperate climate with an average temperature of 24 ± 5°C. The second locality has a sub-​tropical climate, where a temperature of 26 ± 2°C can be expected.

82  Francisco J. Vergara-Solana et al. The impact that an increase in sea surface temperature may have on biomass and the economic performance of the two farms will be evaluated with scenarios of gradual increases from 0.5 to 5°C. Assuming that both farms have open production systems, covering an area of 100 hectares, for comparative purposes, production strategies and costs are the same between sites, using representative industry values. To model a complex system, such as aquaculture production, the theory proposes the possibility of studying a complex system by analysing the sub-​systems that compose it and the relationships that exist between them. Thus, the variables that affect shrimp production in this example are first identified (e.g., Biological sub-​ model; Products; Market; Income; Environmental sub-​model; Economic sub-​ model; Technological sub-​model; Costs; Performance indicators) (Figure 6.3). Once the system components have been identified, the mathematical modelling of each of the sub-​systems that compose it is performed. All model outputs are shown assuming management under the optimal harvest time (OHT) system. OHT is the point in time when maximum benefits are achieved and is dependent on facilities, production protocols, species, and environmental factors. One of the main effects of increasing sea temperatures is a reduction in OHT (Figure 6.4a). If the current temperature is maintained, production in the semi-​ tropical zone would have an OHT of 19 weeks, while production in the temperate zone would have an OHT of 20 weeks.

Figure 6.3 Conceptual representation of a shrimp aquaculture production system, where the sub-​systems or sub-​models that make up the metasystem are shown. The relationship between these subsystems is represented by arrows with a cause–​effect direction.

Aquaculture and climate change  83

Figure 6.4 Effect of sea temperature increase (°C) on different indicators of bioeconomic performance indicators: (a) optimum harvest time; (b) harvest weight; (c) survival; (d) harvested biomass; and (e) profitability.

84  Francisco J. Vergara-Solana et al. An increase of 1°C with respect to the current temperature would maintain the OHT for the semi-​tropical area but would reduce the OHT in a temperate zone. This pattern repeats as temperature increases. A reduction in OHT has a significant effect both on harvest weight at that point and on individual survival (Figures 6.4b and 6.4c). Temperature reduces survival until reaching a breaking point, where a new OHT is found, which rewards an increase in survival. The opposite effect can be observed in harvest weight. As temperature increases, harvest weight increases until reaching a new OHT, which is obtained with a lower harvest weight. These two factors define what the harvested biomass (Figure 6.4d) will be and where the same breakpoints caused by changes in OHT can be appreciated. In general, an increase in productivity derived from an increase in temperature can be observed. It can also be seen how, as the temperature increases, the production differences between the two zones narrow. Regarding economic performance, a linear increase in the benefits can be observed as the temperature increases (Figure 6.4e). In addition to the effect of temperature on growth and mortality, a rigorous analysis would be required to assess the temperature increase effect on other factors relevant to production. Since as the temperature increases, the concentration of dissolved oxygen in water decreases, the growth of pathogens is enhanced, and the feed conversion rate may be affected. 6.8  Final remarks In light of estimations, a 20 million ton increase in aquaculture production by 2030 is needed to meet imminent food demand, which by itself is a significant challenge. And yet, this challenge becomes even more complex if we consider climate change. In this context, the aquaculture sector faces the task of mitigating its negative ecological impacts and proactively managing the uncertainties and risks of climate change. The impacts of climate change on aquaculture production systems are intricate and multifaceted. While climate change is often linked to temperature increases, its effects are far more complex due to the intricate interactions between the ocean and the atmosphere. These encompass changes in physicochemical parameters, such as air temperature, sea surface temperature (SST), ocean pH, dissolved oxygen availability, and shifts in meteorological, oceanographic, and ecological patterns. These patterns include sea level rise, changes in wind intensity, water column stratification, altered precipitation, shifts in upwelling patterns, modifications in primary ocean productivity, the formation of hypoxic zones, increased power and frequency of algal blooms, storms, and hurricanes, and changes in disease and parasite outbreaks. Adapting to the challenges posed by climate change involves two key strategies: mitigation of the environmental impacts caused by productive activities

Aquaculture and climate change  85 and adaptation to the changing climate conditions. Adaptation consists of policies, technical support, and community capacity-​building efforts, extending beyond the aquaculture sector alone. The intricate balance between mitigation and adaptation, guided by science and fostering the involvement of stakeholders of different sectors and levels (from local to international solutions), will pave the way toward a more resilient and sustainable aquaculture future. 6.9  Chapter review questions 1 Describe some positive impacts that climate change may bring and how the aquaculture industry can capitalise on them. 2 How does carbon dioxide affect seawater chemistry, and how can it affect aquaculture production? 3 From the government’s perspective, how can they influence the aquaculture sector’s adaptation to climate change? 4 Mention examples of how the aquaculture sector can adapt to climate change through private initiatives. Recommended readings Cochrane, K., De Young, C., Soto, D., & Bahri, T. (2009). Climate change implications for fisheries and aquaculture. FAO Fisheries and Aquaculture Technical Paper, 530, 212. Dabbadie, L., Aguilar-​Manjarrez, J., Beveridge, M. C., Bueno, P. B., Ross, L. G., & Soto, D. (2019). Effects of climate change on aquaculture: Drivers, impacts and policies. Impacts of Climate Change on Fisheries and Aquaculture, 449. De Silva, S. S., & Soto, D. (2009). Climate change and aquaculture: Potential impacts, adaptation and mitigation. Climate change implications for fisheries and aquaculture: Overview of current scientific knowledge. FAO Fisheries and Aquaculture Technical Paper, 530, 151–​212. Galappaththi, E. K., Ichien, S. T., Hyman, A. A., Aubrac, C. J., & Ford, J. D. (2020). Climate change adaptation in aquaculture. Reviews in Aquaculture, 12(4), 2160–​2176. Mackintosh, A., Hill, G., Costello, M., Jueterbock, A., & Assis, J. (2023). Modeling Aquaculture Suitability in a Climate Change Future. Oceanography. Maulu, S., Hasimuna, O. J., Haambiya, L. H., Monde, C., Musuka, C. G., Makorwa, T. H., Munganga, B. P., Phiri, K. J. and Nsekanabo, J. D., (2021). Climate change effects on aquaculture production: Sustainability implications, mitigation, and adaptations. Frontiers in Sustainable Food Systems, 5, 609097. Reid, G. K., Gurney-​Smith, H. J., Marcogliese, D. J., Knowler, D., Benfey, T., Garber, A. F., … & De Silva, S. (2019). Climate change and aquaculture: Considering biological response and resources. Aquaculture Environment Interactions, 11, 569–​602. Soto, D., Ross, L. G., Handisyde, N., Bueno, P. B., Beveridge, M. C., Dabbadie, L., Aguilar-​ Manjarrez, J., Cai, J. and Pongthanapanich, T., (2019). Climate change and aquaculture: Vulnerability and adaptation options. Impacts of Climate Change on Fisheries and Aquaculture, 465.

86  Francisco J. Vergara-Solana et al. Box 6.1  Strengthening the adaptive capacity of aquaculture communities to climate change in Chile José Aguilar Manjarrez Aquaculture officer for FAO Latin America and the Caribbean Regional Office Climate change is a reality for the entire planet, and Chile is no exception. Chile has a high degree of vulnerability to climate change, and many productive sectors see their conditions profoundly modified with the artisanal fisheries sector and small-​scale aquaculture being the most affected. Thus, actions that support and promote the adaptation of these sectors are needed to address climate change and other related issues. To face this challenge, the pilot project “Strengthening the adaptive capacity to climate change in the fisheries and aquaculture sector of Chile” was launched in 2017. The project, which is due to end in June 2021, concentrates on reducing vulnerability to climate change in four caletas (In Chile, a “caleta” refers to an area designated for administrative purposes where small-​scale fishing activities take place) in different regions of Chile. This project, a pioneer in Chile, was executed by the Undersecretariat of Fisheries and Aquaculture (SUBPESCA) and the Ministry of the Environment implemented by the Food and Agriculture Organization of the United Nations (FAO), with funding from the Global Environment Facility (GEF). The project has strengthened public and private institutional capacities, improved the adaptive capacity of artisanal fisheries and small-​scale aquaculture, and promoted knowledge and awareness about climate change in communities. Seven Inter-​institutional Working Groups were created that brought together key actors in a common workspace; an Interoperable Information System was designed that systematises fishing, aquaculture, and climate change variables; more than 300 public officials and decision-​makers were trained in adaptation to climate change. More than 140 artisanal fishers and small-​scale aquaculture farmers were trained in adaptation to climate change, giving special emphasis to the participation of women, who exceeded 50 percent of the attendees. In addition, a participatory environmental monitoring training programme was created to promote measurements and recording practices of critical environmental variables by fishers and small-​scale farmers. A total of 26 experimental initiatives to explore new adaptation practices in the pilot caleta were conducted: (i) a novel proposal for an Identity Seal to give recognition to the efforts made by the coastal communities to adopt initiatives to adapt to climate change; (ii) identification, adaptive and sustainable exploitation, and alternative processing of bycatch; (iii) local production of value-​added fishery products post capture; (iv) development strategies for tourism to create complementary activities for fishers and small-​scale

Aquaculture and climate change  87

Figure 6.5 Women in Caleta Tongoy in their first Japanese oyster seeding. With this practice, this group of women began an activity in aquaculture carried out mainly by men in the caleta. This initiative was a success, generating products with added value through processing methods and the basis for this group of women to become a cooperative to continue developing the activity and being able to scale-​up commercially. Photo by ©FAO/​ Marcelina Novoa.

farmers; (v) and experimental small-​scale aquaculture of Chilean mussel, Choro mussel, Japanese oyster (Figure 6.5), red seaweed, and improvement of mussel seed collection to explore new productive alternatives for coastal communities. The project has implemented communication and training initiatives for more than 5000 artisanal fishers, small-​scale farmers, and the general public. A communication strategy has been instituted to include efforts that contribute to the creation of new public policies; a vast number of pedagogical and informative material has been published or in press. Small-​scale aquaculture is considered an economic activity with opportunities to grow because of its potential to strengthen and complement the work of artisanal fishers affected by the decline of some of their target and traditional resources as a consequence of climate change. The outputs of the project will increase the overall resilience of Chilean fisheries and the aquaculture sectors providing guidance to neighbouring and

88  Francisco J. Vergara-Solana et al. further afar countries. As part of the project, a sustainability strategy is being prepared and discussed among relevant institutions to provide continuity to project activities and also form the basis to replicate similar efforts for the rest of the caletas in Chile. The biggest challenge is to ensure the post-​project sustainability of the outcomes, particularly at the national and regional levels. This challenge requires a high degree of commitment and leadership from the government given the COVID-​19 emergence and new priorities, particularly with regard to engaging with national institutions, policies, and programmes to ensure systematic uptake of project recommendations, methodologies, systems, results, and best practices.

References Aguilar-​Manjarrez, J., Godoy, C., Vasquez, C. & Novoa, M. 2020. Diversification of productive activities and innovation: Keys to reducing vulnerability of artisanal fisheries to climate change in Chile. FAO Aquaculture Newsletter, 62, 20–​22. (www.fao.org/​3/​ cb155​0en/​cb155​0en.pdf) Barbieri, M. A., Aguilar-​Manjarrez, J. & Lovatelli, A. 2020. Guía básica —​Cambio climático pesca y acuicultura. Fortalecimiento de la capacidad de adaptación en el sector pesquero y acuícola chileno al cambio climático. Santiago de Chile, FAO. (www.fao.org/​3/​cb159​8es/​CB159​8ES.pdf) Barange, M., Bahri, T., Beveridge, M. C. M., Cochrane, K. L., Funge-​Smith, S. & Poulain, F. (2018) ‘Impacts of climate change on fisheries and aquaculture: synthesis of currrent knowledge, adaptation and mitigation options’, FAO Fisheries and Aquaculture Technical Paper (FAO) eng no. 627. Available at: (https://​agris.fao.org/​agris-​sea​rch/​sea​ rch.do?recor​dID=​XF201​8002​008) (Accessed: 24 May 2021). Chopin, T., Cooper, J. A., Reid, G., Cross, S. & Moore, C. (2012) ‘Open-​water integrated multi-​trophic aquaculture: environmental biomitigation and economic diversification of fed aquaculture by extractive aquaculture’, Reviews in Aquaculture, 4(4), 209–​220. DOI: (https://​doi.org/​10.1111/​j.1753-​5131.2012.01074.x) Costello, C., Cao, L., Gelcich, S., Cisneros-​Mata, M. Á., Free, C. M., Froehlich, H. E., Golden, C. D., Ishimura, G., Maier, J., Macadam-​Somer, I., Mangin, T., Melnychuk, M. C., Miyahara, M., de Moor, C. L., Naylor, R., Nøstbakken, L., Ojea, E., O’Reilly, E., Parma, A. M., Plantinga, A. J., Thilsted, S. H. & Lubchenco, J. (2020) ‘The future of food from the sea’, Nature, 588(7836), 95–​100. DOI: 10.1038/​s41586-​020-​2616-​y Crowley, E. & Aguilar-​Manjarrez, J. 2020. [OPINIÓN]. Acuicultura de pequeña escala en Chile. Revista AQUA, Acuicultura +​ Pesca. (www.aqua.cl/​colum​nas/​acui​cult​ura-​de-​ pequ​ena-​esc​ala-​en-​chile/​) FAO. 2019. Proyecto Fortalecimiento de la Capacidad de Adaptación en el Sector Pesquero y Acuícola Chileno al Cambio Climático. Folleto. Santiago, 7. (www.fao.org/​3/​ca578​ 5es/​CA578​5ES.pdf) FAO. 2021. Inter-​institutional virtual seminar on ”Strengthening the adaptive capacity to climate change in the fisheries and aquaculture sector of Chile: Project achievements

Aquaculture and climate change  89 and opportunities for its sustainability”. (www.fao.org/​chile/​notic​ias/​det​ail-​eve​nts/​es/​ c/​1390​751/​) Lovatelli, A. & Inostroza, F. 2017. Adaptation of fisheries and aquaculture to climate change in Chile. FAO Aquaculture Newsletter, 57, 29–​30. (www.fao.org/​3/​i78​51e/​i78​51e.pdf) Lovatelli, A., Godoy, C. & Contreras, J. 2019. Technological innovation in mussel seed collection: A response to climate change from fishing communities in southern Chile. FAO Aquaculture Newsletter, 60, 33–​34. (www.fao.org/​3/​ca522​3en/​ca522​3en.pdf) Maulu, S., Hasimuna, O. J., Haambiya, L. H., Monde, C., Musuka, C. G., Makorwa, T. H., Munganga, B. P., Phiri, K. J. & Nsekanabo, J. D., 2021. Climate Change Effects on Aquaculture Production: Sustainability Implications, Mitigation, and Adaptations. Frontiers in Sustainable Food Systems 5.

References 1 Cochrane, K. L., Perry, R. I., Daw, T. M., Soto, D., Barange, & M. y De Silva, S. S. (eds.) (2009). Climate change implications for fisheries and aquaculture: Overview of current scientific knowledge. FAO Fisheries and Aquaculture Technical Paper No. 530. Roma, FAO. 2 Phillips, B. F. y & Pérez-​Ramírez, M. (eds.) (2017). Climate Change Impacts on Fisheries and Aquaculture: A Global Analysis. John Wiley & Sons. 3 Jayasinghe, J. M. P. K., Gamage, D. G. N. D., & Jayasinghe, J. M. H. A. (2019). Combating climate change impacts for shrimp aquaculture through adaptations: Sri Lankan perspective. Sustainable Solutions for Food Security: Combating Climate Change by Adaptation, 287–​309. 4 Puspa, A. D., Osawa, T., & Arthana, I. W. (2018, June). Quantitative assessment of vulnerability in aquaculture: climate change impacts on whiteleg shrimp (Litopenaeus vannamei) farming in East Java Province. In IOP Conference Series: Earth and Environmental Science (Vol. 162, No. 1, p. 012027). IOP Publishing. 5 Blank, J. M., Morrissette, J. M., Farwell, C. J., Price, M., Schallert, R. J., & Block, B. A. (2007). Temperature effects on metabolic rate of juvenile Pacific bluefin tuna Thunnus orientalis. Journal of Experimental Biology, 210(23), 4254–​4261. 6 Gazeau, F., Parker, L. M., Comeau, S., Gattuso, J. P., O’Connor, W. A., Martin, S., ... & Ross, P. M. (2013). Impacts of ocean acidification on marine shelled molluscs. Marine Biology, 160, 2207–​2245. 7 Chávez-​Villalba, J., Arreola-​Lizárraga, A., Burrola-​Sánchez, S., & Hoyos-​Chairez, F. (2010). Growth, condition, and survival of the Pacific oyster Crassostrea gigas cultivated within and outside a subtropical lagoon. Aquaculture, 300(1–​4), 128–​136. 8 Koch, M., Bowes, G., Ross, C., & Zhang, X. H. (2013). Climate change and ocean acidification effects on seagrasses and marine macroalgae. Global Change Biology, 19(1), 103–​132. 9 Galappaththi, E. K., Ichien, S. T., Hyman, A. A., Aubrac, C. J., & Ford, J. D. (2020). Climate change adaptation in aquaculture. Reviews in Aquaculture, 12(4), 2160–​2176. 10 Longdill, P. C., Healy, T. R., & Black, K. P. (2008). GIS-​based models for sustainable open-​coast shellfish aquaculture management area site selection. Ocean Coast Manage, 51, 612–​624. 11 Besson, M., De Boer, I. J. M., Vandeputte, M., Van Arendonk, J. A. M., Quillet, E., Komen, H., & Aubin, J. (2017). Effect of production quotas on economic and environmental values of growth rate and feed efficiency in sea cage fish farming. PLoS One, 12(3), e0173131.

90  Francisco J. Vergara-Solana et al. 12 Conrad, K. (1993). Taxes and subsidies for pollution-​intensive industries as trade policy. Journal of Environmental Economics and Management, 25(2), 121–​135. 13 Peñalosa-​Martinell, D., Vela-​Magaña, M., Ponce-​Díaz, G., & Padilla, M. E. A. (2020). Probiotics as environmental performance enhancers in the production of white shrimp (Penaeus vannamei) larvae. Aquaculture, 514, 734491. 14 Chopin, T., Cooper, J. A., Reid, G., Cross, S., & Moore, C. (2012). Open-​water integrated multi-​trophic aquaculture: environmental biomitigation and economic diversification of fed aquaculture by extractive aquaculture. Reviews in Aquaculture, 4(4), 209–​220. 15 Peñalosa Martinell, D., Vergara-​Solana, F. J., Almendarez-​Hernández, L. C., & Araneda-​Padilla, M. E. (2020). Econometric models applied to aquaculture as tools for sustainable production. Reviews in Aquaculture, 12(3), 1344–​1359. 16 Calel, R. (2013). Carbon markets: a historical overview. Wiley Interdisciplinary Reviews: Climate Change, 4(2), 107–​119. 17 Barange, M., Bahri, T., Beveridge, M. C., Cochrane, K. L., Funge-​Smith, S., & Poulain, F. (2018). Impacts of climate change on fisheries and aquaculture. United Nations’ Food and Agriculture Organization, 12(4), 628–​635.

Part III

Aquaculture and economics

7 A brief introduction to economics and its relationship with aquaculture Daniel Peñalosa Martinell

Sustainability is composed of three spheres or pillars: the environment, the economy, and society. In this block, composed of Chapters 7–​9, we delve into the relationship that exists between aquaculture and economics. Throughout the following chapter, an overview of general economics, the dominant economic models, and alternative options to these models are presented. Understanding general economics is basic to knowing more about aquaculture innovation, technology, and policy function. To fully understand and study sustainable aquaculture it is a necessity to comprehend at least the basic concepts of economics. These aspects will help us realise, for example, why several existing technologies that could improve the environmental and social aspects of aquaculture have not yet been implemented or why some countries struggle to be competitive in a global market. 7.1 Introduction When we hear the word “economics”, many images arise that sometimes do not fit the reality of this social science. For example, we could think that economics focuses exclusively on maximising the return of capital to a series of shareholders or that its objective is always maximising financial wealth, no matter what, to whom, or how. Although part of these ideas belongs to economic thought, they are only some of its applications and connotations. Economics is usually defined as the science that studies resources, the creation of wealth, and the production, distribution, and consumption of goods and services, to satisfy human needs. Although economic sciences have this general study objective, each conceptual method, objective, and definition delimits how decisions are made. These decisions are not trivial, since they shape the behaviour of states, individuals, cooperatives, organisations, companies, industries, and all the different actors or stakeholders that make up a society. Let us remember that sustainability is composed of three pillars or spheres. In most cases, the environmental sphere is regarded as the “good guy” or the victim, while economics is seen as the “bad guy”, the aggressor, an impediment or reason why the environment is damaged. Even though this is partially accurate, it does DOI: 10.4324/9781003174271-10

94  Daniel Peñalosa Martinell not show the full picture. The economy or the economic system is not a conscious being; it does not do good or bad things but just exists. Human behaviour, rules, and social structures are those that guide the economy’s responses. Contrary to the natural environment, the economic system is an abstract social construction developed to organise, distribute, and allocate all products and services developed by society. Although not flawless due to human nature, if economics is not regulated by a political and economic system, the future of natural resources, such as the atmosphere or oceans, would be doomed. Finally, the authors want to remark that the objective of this chapter is to provide a very general view of economics and some of its mechanisms, but in no way is it intended as a full introduction or review of economic sciences. If the reader wishes to deepen their knowledge of the economic sciences or their application to aquaculture, there are several incredibly good books in the “Recommended readings” section that were written for this purpose. 7.2  Economic scales There are different levels at which management and analyses can be made. The first is on a large scale, where the system is studied as a whole and its impacts are considered in a global, national, or regional manner. This management and analysis level is known as macroeconomics and it attains to product flux (imports and exports), the contribution of industry to the economy of countries and regions, and impacts that have trans-​border consequences, such as pollution and human safety. In today’s society, the economic system is globally interconnected, which means that an effect on one sector or country might have impacts on other seemingly unconnected sectors on the other side of the world. Hence, studying the economy or economics of a sector (in this case, the food production sector or more specifically, the aquaculture industry), not to mention a single farm, has its limitations. That being said, it is virtually impossible (and in some cases unnecessary or inefficient) to include all the interactions that exist between all the different components of the economic system just to optimise individual farm performance. To overcome this difficulty, economists separate the system components into two, according to the analysis scale. As previously mentioned, the first branch of study is known as macroeconomics, which involves the analysis of the economy as a whole. As its name suggests, macroeconomics evaluates the economic system using a holistic view of a region or nation. In the case of aquaculture, this branch of study usually includes the total production, its impact on food security, job creation, and effects on development (on a country’s productivity). Moreover, also important is how the interconnections between countries and industries can impact aquaculture from the effect of war on prices to how a climactic event could have a severe effect on the aquaculture industry due to disruptions to the value chain. (Box 7.1) The second component is known as microeconomics, which considers individual behaviour in decision-​making, understanding an individual as a single person or a firm, in the case of aquaculture, a farm, or even an industry compared to

Economics and its relationship with aquaculture  95 others. Microeconomics then includes in its scope of study all decisions regarding specific farm analysis, resource allocation, process optimisation, profit maximisation, and other individual components of the economic analysis. In some cases, microeconomic tools such as the marginal approach are used to evaluate macroeconomic systems, but, in general, microeconomics is more concerned with individual decisions and their effects. This chapter provides a general perspective on how economists study the different scopes of the relationships that exist between aquaculture production and economics. For this purpose, first, one of the most important notions of economics –​the supply and demand theory –​is presented. 7.3  Supply and demand How does a natural phenomenon in Peru impact aquaculture production in Asia? Why does a war in Europe impact selling prices in America? Which are the most significant players in the aquaculture industry and why? Most of these questions can be answered using basic economic concepts, such as the law of supply and demand. In the case of macroeconomics, supply and demand are studied using aggregate values, that is, total aggregate supply vs. total aggregate demand analyses production and capital flow among countries or regions. The result of this analysis is what determines the real gross domestic product (GDP) of a country. In the case of microeconomics, the law of supply and demand states that in a perfectly competitive market, goods supply (or production) and demand set their price when equilibrium is achieved (Figure 7.1). In other words, the point where the supply curve meets the demand curve is equal to the price of the merchandise, which means that when a shock in a system impacts either supply or demand, the equilibrium shifts directly, affecting the price of that product in the short run. This analysis can be performed for a single product, a group of products, or an industry. Therefore, to answer the questions at the beginning of this section, the first thing is to understand the different components and major players within the aquaculture industry and their commercial relationships. Then, supply and demand theory can be applied to estimate the possible impact of an event. For example, how does a natural phenomenon in Peru impact the Asian aquaculture industry? First, we need to know that Peru accounts for the largest reduction fishery in the world, meaning it captures large amounts of fish destined for the production of fishmeal and fish oil. Let’s suppose a natural phenomenon such as El Niño occurs and changes the ocean’s surface temperature. In that case, the environmental characteristics of the ocean impact the amount of fish available to catch, therefore, the production of fishmeal and fish oil, in turn, affects aquafeed production since it is the primary source of oily fats and proteins in most commercial aquafeed. If we go back to the supply and demand law (Figure 7.1) notice that if the quantity of fish available is reduced and the demand stays the same, then the price of the goods will increase in a competitive market (from P1 to P2). Furthermore, the feed demand is associated with the aquaculture production increase. An increase in demand will also shift the

96  Daniel Peñalosa Martinell

Figure 7.1 A general representation of the behaviour of the supply and demand curves and an example of what happens to the price equilibrium under changes in supply. If there is an increase of production (from Q1 to Q2), then there is a shift in the supply curve from S1 to S2, if the demand remains equal, this supply shift causes the price at equilibrium to move from P1 to P2.

curve, so the reduced supply and increased demand both impact the equilibrium and surely increases the price of aquafeed, at least in the short run. If the price of aquafeed increases, then the production costs of feeding aquaculture as a whole also increase due to the large component of production costs associated with feeding, which can be up to 70% of the total variable costs. This leads to a sharp increase in costs that either increases the price of products or reduces the farmers’ revenue. In the case of aquaculture, the market is highly competitive. Perfect substitutes for all products (from fisheries, for example) exist, so most of the time, the farmers are what is known as price-​takers, meaning that they do not control much of the global supply so a change in their production shifts the curve. Thus, farmers have to take the prices set by the world markets, and it is more likely they will absorb the impact of a shock. The changes for those species where aquaculture dominates the market and the industry as a whole act like a price-​setter (meaning that their production is enough to affect the market prices if drastically changed). For example, in shrimp and salmon, when the input price increase is global, the price increase of the product would also be global and the shock might be absorbed by the final customer. In this scenario of a globally connected industry, sustainability and sustainability analyses are more important than ever since changes in one part of the world or in

Economics and its relationship with aquaculture  97 the system as a whole will surely have an impact on local aquaculture production. Furthermore, not only will the impact be due to global environmental challenges such as climate change but also to other significant issues related to society, such as wars and massive migrations or even economic shocks such as uncontrolled inflation or recessions, making economic analysis a highly complex discipline and, usually, a tough one to forecast. 7.4 Macroeconomics As previously mentioned, macroeconomics covers the analyses of countries and, in our case, the industry as a whole; although it might seem simple at first sight, the reality is that the current status of the economic system based on globalisation requires a holistic understanding of all the aquaculture components and how they interact in a globalised economic system. The macroeconomic analysis does not only deal with the financial aspects of the industry but also includes several other indicators that are not necessarily financial. Aquaculture is within the primary production industries, which means that its growth and performance can be significant even for national security, not only because of the revenue it can produce but also its impact on food security, job creation, and national development. In that respect, aquaculture can be classified into two very distinctive groups: (1) commercial aquaculture where the main objective of production is to make profits, and (2) livelihood or rural aquaculture where the objective of the production is to supplement nutrient intake for farmers through small operations with no selling intent. The differentiation provided earlier is extremely important when it comes to macroeconomic analysis and especially for the development of public policy, a component that usually concerns a branch of economics known as political economics. The macroeconomic analysis uses several different indicators depending on the subject of evaluation (welfare, growth, or even happiness)1. Nevertheless, one of the most significant ones, and the one that has guided the management of the economy over more than 60 years is the gross domestic product (GDP), obtained by the balance between aggregate supply and aggregate demand. Today, GDP (along with a battery of other indicators) estimates the growth of the economy, which is currently associated with the health of the national economy. However, the use of GDP and the notion of “infinite growth” as economic health indicators is challenged by today’s economists2, with some even proposing a “degrowth” strategy to cope with the finite resources of our planet3,4. Macroeconomics and aquaculture are heavily linked, particularly in countries that rely on aquaculture as a significant source of employment, food, and even foreign exchange. China has historically been the world’s largest producer of farmed fish and seafood. Aquaculture plays a crucial role in China’s economy, and it has a substantial impact on their GDP (around 6% of their agricultural GDP for 2020)i The aquaculture sector in China provides employment opportunities, generates export revenue, and contributes to the domestic food supply5.

98  Daniel Peñalosa Martinell Other countries with a significant impact of aquaculture on GDP include Norway and Chile, which are known for salmon farming; Vietnam, a major exporter of various fish and seafood products; Ecuador, Thailand, and Indonesia are also notable for their aquaculture industries and their contributions to the economy6. 7.5 Microeconomics As covered earlier in this chapter, microeconomics deals with the financial and economic components at a farm or industry level. Most components of microeconomic analysis and decision-​making used in aquaculture are covered in Chapter 10. Nonetheless, this chapter introduces two of the most significant components of the analysis, the production and profit functions. 7.5.1  The production function

In microeconomics, a production function is a relationship that describes the quantity of goods or services produced by a specific set of resources or inputs. Most aquaculture farms tend to focus on the production of biomass. Whether biomass is then used for food (the vast majority) or for some other industry (such as the pharmaceutical industry in the case of algae for example, or fashion in the case of crocodiles or pearls), all producers are looking forward to producing biomass, which is the total weight of living organisms in a specific volume or area, i.e., a farm. Since the objective has been established to produce biomass, the dependent variable of our production function will be biomass. Now that the output is established, the inputs needed to obtain such output should be determined. As stated before, biomass is the total weight of the individuals present on the farm at a specific moment, thus biomass is equal to the number of individuals at a certain moment multiplied by the individual weight of each of them at that same time or expressed in a simple mathematical function Bt = N tWt Where Bt corresponds to biomass in time t; N t � is the number of organisms in the ponds or tanks at that same time t; and Wt � is the average individual weight of each organism at the same time t. With that simple relation, we have developed our very first basic but powerful production function. The truth is that capturing the individual weight of each organism in the pond is nearly impossible at a commercial farm level. Furthermore, this information should be obtained on periodic bases (at least once per week), so capturing, weighing, and separating each organism is not the best way to do it. Sampling is a standard method used to minimise the efforts and maximise the output of data. This method consists in obtaining statistically significant samples of

Economics and its relationship with aquaculture  99 the farm and obtaining average values for weight or length as well as the number of individuals. Once a couple of production cycle growth data have been obtained, we can model the expected average individual weight. For this purpose, several functions and variations exist. One can model the intrinsic growth rate and from there extrapolate to individual weight or directly model weight using variations of famous functions, such as von Bertalanffy’s or Gopertz’s, as presented in Chapter 10. Once a model is selected, the curves can be fitted using their own historical data. Modelling biomass (production function) helps make better decisions regarding the farm: from the amount of feed provided (which can be around 60–​70% of the variable costs) to the best time to harvest (should I harvest smaller organisms faster or bigger ones in a longer period?). In the end, the model will be a tool to use and improve the profits of the farm by optimising processes. The models can then be further sophisticated, accounting for size heterogeneity, changes in the growth rate associated with production density (linked with partial harvests), or even accounting for water quality indicators and their influence on biomass, such as the effects of temperature, oxygen, pH, salinity, or ammonia on growth and survival. This sophistication allows for a better understanding of the system, which can help to optimise production through improved aeration methods or specific water exchange protocols. Now, remember that several components will impact this production function. Since they are living organisms, factors like feed, nutrition, environmental components, genetics, and time will have an impact on both parts of the production function. The methods for modelling and the most used growth and survival models are described in Chapter 10, but keep in mind that those are not the only existing models; one can twitch and modify the functions to include all different components of production that will impact growth and survival and hence have an effect on the production function. As observed, the production function in aquaculture only includes biological components. This function only defines the quantity of biomass produced, but the economic piece of the farm is missing. To determine how much money a farm could make in income ( I t ) from the sale of their products, the first financial aspect of the analysis should be included, the selling price of the product ( Pt ) , and obtaining the income function. I t = Bt Pt Remember that income is the amount of money that the farmers receive for their product, which is biomass produced times the price of such biomass in the market. This is where the macroeconomic aspects of aquaculture meet the microeconomic analysis; most of the time, the farmers do not have control over the selling price since this is determined by the market (the law of supply and demand). If the farmers have information regarding the behaviour of the market (how prices change) in certain seasons or under certain circumstances, that might give them an

100  Daniel Peñalosa Martinell advantage because harvesting their production will be possible whenever prices peak, maximising the farm income. 7.5.2  The profit function

Developing sound economic analyses requires a robust framework that supports the model and assumptions. In the case of microeconomics, we first need to set or assume the objective of one or all the commercial farms, which is maximising their profits, in most cases, from biomass production, and in turn from the growth and survival of fish, shellfish, or algae. Although we are now entering the realm of finance and economics, we have only looked at the income part of the equation. The success of an aquaculture farm, as in any other agribusiness, consists of its capability to produce biomass at a lower cost than its selling price. Since we have established that the goal is to maximise profits, we need to define a profit function that includes the financial components of the production along with the biological ones, showing the effect that input costs (Ct ) , as well as output price, have on a farm’s profitability.

π t = I t − Ct We now have the profit (π_​t) function, which is the base to determine how the decisions and other economic agentsii may improve or diminish performance, getting nearer or further from fulfilling the objective. Microeconomics is much more than just the profit function; it also studies the impact that the choices of the different economic agents have on the markets through the effects on consumption, production, and price. Nevertheless, the objective of this book is not to deepen into this vast branch of the Economic sciences. If the reader is interested in deepening knowledge in these aspects, such as how to determine the reaction of consumers to changes in supply or price, or even optimising the performance of a farm, we encourage them to look into the recommended readings section for specialised books that help explore these ideas. 7.6  The economy and natural resource management Since economics is the science that studies the administration, production, and consumption of resources, this definition includes both anthropogenic and natural resources, understanding them as all those elements of nature that contribute to the well-​being of humanity. Within natural resources, they can be classified into two large groups of possible exploitations from the temporal point of view. On the one hand, non-​renewable resources are found, which are those that have a finite stock and their turnover or renewability requires extremely extended periods of time, such as metals or oil. On the other hand, renewable resources, such as water or the atmosphere have a short turnover period, which means they can replenish within a reasonable period if left unexploited or well-​managed. It should

Economics and its relationship with aquaculture  101 be noted that their “renewable” characteristic does not make these resources inexhaustible but instead gives them the plasticity to replenish themselves in a short period of time if appropriately exploited. In addition to the temporality of natural resources, they can also be classified according to their ownership or property rights. In that sense, resources can either be under private property –​a single owner or group of owners of a resource and that owner or group of owners hold exclusive rights to exploit or give permission to exploit it. For example, mines or agricultural land, or through common use which means that no single owner exists and the resource belongs to a society, such as the marine environment or the atmosphere. These two classifications are of vital importance for understanding the economic management of natural resources. 7.6.1  Private vs. common resources

In the case of privately owned resources, such as an aquaculture farm, the concept of management and the economics surrounding it are similar to other industries because of the private nature of the resources. In other words, the farmers have the ability to control the number of organisms they seed, the feed used, and other production inputs to determine the optimal output of the operation. The fact that the products in hand are living organisms gives certain complexity to management due to the unpredictable or unprecise response of the farmed organisms to the farmer inputs. That is, growth is not the same for all the organisms given a certain amount of feed, or mortality might be unpredictable. However, the farmers still have ultimate control over production. Of all the natural resources, those that have characteristics of common use are the most complex to manage due to the concept of “the tragedy of the commons” described by the ecologist Garrett Hardin7. This author shows that in an open system (without regulation), common resources tend to exhaustion. If there is no regulation and individuals act in a rational self-​interest way, that is, all members in a group use common resources for their own gain, and with no regard for others, all-​natural resources would still eventually be depleted through what is known as a race for resources. Unfortunately, people try to get as much of the resource as possible for their gain before someone else takes the opportunity. The root of this problem stems from two very relevant economic concepts for the economy of natural resources: externalities and the parasite or free-​rider problem. 7.6.2  The concepts of externalities and free-​riders

An externality is defined as a situation in which the costs or benefits of production or consumption of some goods or services are not reflected in their market price. Externalities can be either positive or negative, depending on the impact generated and the focus of the analysis. On the other hand, a parasite or free-​rider is a social entity (whether individual or an enterprise) that benefits from externalities or common goods without contributing to financing this merchandise.

102  Daniel Peñalosa Martinell A classic example of these concepts is highly tied to sustainable sciences –​the emission of greenhouse gases (GHG) –​ the main cause of climate change. They are emitted into the atmosphere as a result of several natural events and anthropogenic activities. In the case of anthropogenic activities, GHG emissions are highly linked with energy generation and consumption. In the case of aquaculture, those productions that are intensive in feed and energy (such as fed aquaculture and recirculating aquaculture system) have higher GHG emissions. An example of free-​riders can be found in aquaculture parks, where several farms share a common water inlet or reservoir. All the farms from the industrial park benefit from good maintenance and water management of the water inlet pumping system. Now imagine the need for renewing the machinery of the pumping system and one farm is not willing to pay for such improvement. Since the rest of the group are aware of the benefit of doing it, they pay for the renewal. Possibly, the park as a group does not have the resources or authority to restrict water access to the farm that did not pay. Now, this farm benefits from better equipment without paying for it, which makes it a free-​rider. It is important to highlight that Hardin’s tragedy of the commons relies on two major suppositions which need to be accounted for when analysing the access to a common resource. The first is the self-​interest of the producers, meaning they always look for their benefit above all and therefore “race for resources”. This supposition can be challenged by arguing the fact that, in any community, there is regard for the neighbour. In other words, humans (social beings by nature) look for the well-​being of humanity as a whole. If this were not true, social structures would not exist as we know them, since everyone would look only after themselves. The second supposition concerns the regulatory aspects. For the tragedy of the commons to occur, no regulations whatsoever should exist towards the use of the common stock. This supposition can be heavily challenged since the creation of communities and societies comes hand in hand with the development of a set of rules and regulations to coexist. Since the beginning of human societies, there have been rules and regulations regarding the use of natural resources8, the occurrence of the tragedy of the commons relies then on the effectiveness of the rules and regulations developed. 7.7  Some relevant economic schools of thought We have covered the way economists tackle the methods to model or evaluate economic activity depending on the scale or approach (bottom-​up for microeconomics, and top-​down for macroeconomics), but trying to understand and predict the behaviour of the economy is only a part of it. The second part is how to manage it through implementing regulations and policies. In this regard, how we understand the economy, its limitations, strengths, and purpose determines how we stir it towards the desired outcome. The current dominant school of thought to manage an economy is known as market capitalism. The core of this trend sustains that markets are capable of self-​ regulation and that by letting them self-​regulate, the economy thrives thanks to the

Economics and its relationship with aquaculture  103 existence of competition. According to this school, the way in which all society benefits from increased market competition and reduced regulation is through the spillover generated by the increasing gains from corporations, also known as Okun’s “leaking bucket”9. Several economists have challenged the existence of the spillovers predicted by Okun10 as well as the efficiency of market capitalism as we know it today. Remember that economics is not a natural science or an exact science, so its development and impact depend on society, its vision, morals, culture, and the objectives it sets. The economy is guided by a series of assumptions, concepts, and models that determine “in the best possible way” how to manage assets. Thus, even if all economists had the same objective and vision of what the economy should do (for example: use resources in such a way that social welfare is maximised in an equitable and collective manner), a discrepancy in the method and the models to achieve that goal may exist. With this in mind, there is a series of currents or “countercurrents” that criticise and propose alternative methods to the current economic system. For the most part, the alternative systems that are contemplated today derive from a main concern, and that is nature. Whether due to its degradation or its “finite” quality, natural resources and nature as a whole are the central axis of discussions about the economy and its long-​term projection. On that line, three alternative schools of thought have dominated the economic discussion from a sustainability perspective: ecological economics, environmental economics, and circular economy. 7.7.1  Ecological economics

All economic agents generate externalities, however, some are more harmful than others. Although the first thing that can come to mind regarding the relationship of the economy with sustainability is environmental deterioration, it is necessary to think a little further. The economy, economic policies, public policies, and the economic school of thought to which a country or a group of countries adheres are responsible for social welfare (from how much wealth is generated, how it is distributed, and how it can even be applied to the possibility of providing social health services, pensions, or subsidies). It is for this simple reason that the economy is one of the pillars of sustainability. Deepening into this subject, we can find some concepts that are of interest to understanding the relationship of the economy with sustainability and the need to tackle it and direct it in the best possible way. The set of interdisciplinary sciences in charge of studying the sustainable economy is called ecological economics (not to be confused with the economics of natural resources or with environmental economics). In general, ecological economics maintains that the study of the economy must be done from a holistic perspective, understanding that the economy is part of society and it belongs to nature. For this reason, the economy belongs, indirectly,

104  Daniel Peñalosa Martinell to nature, so it must account for the relationship that the exploitation of resources has with the ecology of the system and the society that is included in it. Thus, ecological economics includes within its principles and models biological and social aspects together with economic principles, breaking the paradigm of egoism and the concept of homo œconomicus (that is, that the unitary entity of the economy is human, who is selfish, so he will always look first for his individual well-​being, and he is rational, that is, he will always make decisions that improve his current state) on which all neoclassical economic theory is based. The development of the theory of ecological economics could be the missing tool to accelerate the development of humanity towards a more united society, with a higher value and understanding of nature and the services it provides us, a more adequate feeling of justice and an equitable distribution of wealth, reducing problems of hunger, inequality, gender, and poverty, while attacking other harmful elements of current production such as contamination of aquifers, reduction of biodiversity, and climate change. 7.7.2  Environmental economics

The model that currently governs the global economy is the neoclassical vision of how the economy should behave. One of the principles that govern this behaviour is based on the Solow economic growth model, which proposes the following: Y = K α ( AL )

1− α

Where Y represents total production, K is capital, A is a technological constant, L is labour or human capital, and α is the coefficient of diminishing marginal returns, that is, the rate that determines the growth of Y from a marginal point of view. Although this model explains the increases and reductions in production globally, it makes an assumption that is the main criticism of the system and it is the definition it makes of capital. According to modern theory, capital as a general concept is composed of four types of capital: labour or social (KL), financial (KF), natural (KN), and institutional or intellectual (information, KI). Therefore, according to neoclassical economics, capital can be defined as: K = KL + KF + KN + KI This definition makes all types of capital perfect substitutes. Thus, theoretically, an increase in financial capital can substitute a reduction in natural capital, maintaining growth sustainably. Within the scope of sustainability, this economic theory is known as “weak sustainability”, since it states that increases in technologies and improvements in production processes associated with competition (greater financial capital and greater intellectual capital) justify the impacts on natural capital, so it is not necessary to make a change to the definition of capital.

Economics and its relationship with aquaculture  105 Contrary to this idea, environmental economics (not to be confused with natural resource economics) proposes a paradigm shift. Environmental economists take natural capital as the axis of their theory because the externalities derived from production can have a significant effect on the environment. This effect had not been taken into account and the externalities were absorbed by the ecosystem and finally by society. For this purpose, natural economists divided natural capital into different categories, with the aim of being able to carry out economic valuations (assign a monetary value to natural capital) based on its use, activity, ability to renew itself, and the speed at which it happens. This valuation (which includes all environmental components with or without a market) allows for estimating the value of the externalities incurred by the rest of the components of the economic system and developing policies to discourage environmental deterioration and/​or taking measures to reduce it. Despite this change, environmental economics can still be seen as weak sustainability. Although natural capital is “revalued” and the analysis focused on environmental externalities and how they can be mitigated, in a certain way and in some cases, direct exchanges should be performed between the different types of capital. This current proposes concepts, such as fines, subsidies, markets, labels, regulations, and production restrictions, among others, as tools to manage natural capital and maintain it over time. 7.7.3  Circular economy

The current production and consumption model follows a linear pattern, where resources or raw materials are obtained, transformed, and finally discarded after use. The circular economy is a proposal to improve this system. The circular economy is not an economic model per se, since it does not make any new proposals regarding the behaviour of the economy, but rather a new model of production and consumption that proposes to reuse waste from production processes. In this manner, new products can be added to optimise the use of available resources. In other words, a circular economy can be developed under any economic ideology, since its principle is to reduce human impact on the environment. 7.7.3.1  Relationship between production and consumption

Since the dawn of economics, the relationship between production and consumption has been studied. Thus, Adam Smith himself in his classic “The Wealth of Nations” was the first to methodologically develop why and how consumption and production are related. In a simplified way and in a perfectly competitive capitalist market, goods and services are produced based on their demand. In turn, both supply and demand are influenced by the price of goods or services. In market theory, the price and quantity of goods or services produced naturally (by market forces) find equilibrium at the point where the supply and demand curves intersect, which is known as the economic equilibrium point (Figure 7.1). Although it may be the case for some goods and services in a fragmented market,

106  Daniel Peñalosa Martinell these curves have been observed to be defined in a very varied way and depending on the product in question. The behaviour of these curves (the slope of the function) is known as elasticity. The elasticity of each curve determines the effect that a price change has on the quantities produced and demanded. For this purpose, goods or services can be categorised, according to this parameter, as elastic –​a minimum change in price has a significant impact on the equilibrium point when the demand curve is horizontal –​or inelastic –​when a price change, whatever it may be, does not affect the quantity demanded, that is, when the demand curve is vertical. By analysing these curves various conclusions can be drawn, one of the most important of which is the relationship between price and demand. A significant reduction in production costs associated with an improvement in technology will be associated with a price reduction, which means an increase in demand and, eventually, an increase in production. This increase brings with it a material and raw material consumption increase, which will have an externality on the environment and eventually on society. In accordance with weak sustainability, the loss of natural capital is offset by the increase in the rest of the capital components, and, in addition, technological improvements will not only lower the price but also reduce the consumption of raw materials. Although a reduction in raw material consumption is necessary for production associated with technological improvements, according to the Jevons paradox11 it will also be associated with a reduction in the sale price. As previously observed, it has the effect of an increase in demand and finally a greater demand for raw material. In other words, the less raw material per product exists, the greater quantity of products will give rise to greater consumption of raw material. 7.8  Economics as a tool for sustainable aquaculture production As mentioned at the beginning of this chapter, the economic system is not a conscious being, meaning that “The System” does not take any dispositions or choices. Society as a whole shapes the economic system and its responses. With that in mind, each component of the economic system (namely: the private, public, society, or consumer sectors) has different economic-​driven tools that can help shift aquaculture towards a more sustainable path. 7.8.1  Private sector economic tools

The private sector, including commercial farms, intermediaries, freezers, retailers, and all other private stakeholders involved in the value chain of the aquaculture industry, is driven mainly by profits. The main objective of the industry is to maximise profits given certain characteristics of inputs and outputs. Although the objective is pretty clear, several ways of getting there exist. The way through which aquaculture organisms are produced can have a more or less environmental or social impact even while generating the same profits.

Economics and its relationship with aquaculture  107 In the past, mainly due to ignorance of the consequences, aquaculture producers had little care for the environmental impact of their productions if that meant higher profits in the short term. This situation directly or indirectly led to a higher risk of production and overall reduced profitability in some aquaculture investments. Thus, the industry pushed to develop technologies and economic instruments that not only help maximising profits in the short run but also reduce environmental impact, ensuring farm sustainability in time. Two of the most promising private economic instruments that can help promote a sustainable aquaculture are Business Intelligence (Box 17.1) and Environmental, Social, and Corporate Governance (ESG) portfolios. 7.8.1.1  Environmental, social, and corporate governance (ESG)

Apart from management and direct optimisation by producers through the Business Intelligence strategy, other stakeholders within the private sector can use other tools to promote sustainable aquaculture, and one of these is within the financial or investment area, especially for loans, insurance, and investment in aquaculture facilities. In most commercial farms, regardless of the scale, finance is one of the main limiting factors to starting a farm and continuing production, mainly due to high infrastructure costs in the first case, and high production costs compared to other food production systems for the second situation. High production costs are more common in fed aquaculture since the protein needed in the feed increases input costs. In the past, loans and most financial products were mainly driven by profits, which means that investments were mostly allocated to the industries that promised higher returns in the fastest way possible with the minimum risk and without accounting for environmental and social impact. This kind of investment generated severe consequences and, eventually, investors figured out that it was not a sustainable way of generating capital. The interlinks that exist between the financial, social, and environmental aspects showed that investment was more sustainable when all these factors were accounted for. Thus, investments would be equally profitable when the investors look at them in the long run and would also have a positive effect on society as a whole. The result was a shift from traditional investment to Environmental, Social, and Corporate Governance (ESG) investments. ESG is not new. For hundreds of years, non-​profit organisations and social groups have invested in responsible ventures, mainly regarding the social sphere, but over the last decade, this movement has gained influence in many different areas of human development, including aquaculture. Aquaculture is a perfect area of opportunity for ESG investors, since millions of people depend on it directly or indirectly because aquaculture is a very significant area of opportunity to improve the social sphere. Furthermore, this field is a significant source of protein, which provides more than 50% of the fish and shellfish destined for human consumption, as discussed in Chapter 16. Many new ideas and interesting innovations are being developed to reduce the environmental impacts of aquaculture, opening the doors to higher production with less environmental

108  Daniel Peñalosa Martinell damage. All of these innovations and impacts need capital for development and implementation and, in some cases, promise a very interesting financial return, hitting all three spheres of sustainability. Capital investment and innovation are significant factors in modern economic models, which are the main driving factors of capitalism towards sustainability. 7.8.2  Public sector economic tools

Aquaculture is the most recent of all food production industries to develop into an industrial and highly productive activity; this situation has some disadvantages, such as a lack of information and policies aimed at reducing its environmental impact. However, it also has some advantages, such as the possibility of implementing new policies and instruments to reduce its environmental impact. Furthermore, according to some writers, aquaculture is the only means to deliver quality protein produced from seafood without depleting the world’s seas2,12. Moreover, this business generates a high rate of employment, particularly in developing Asian and Latin American nations13. As a result, the industry’s key concern is determining how to continue development more sustainably. The externalities of aquaculture vary depending on numerous aspects, such as the production system or location of the facilities. The majority of negative externalities are associated with environmental degradation, such as the release of pollutants (nitrogen and phosphorus in effluents) or greenhouse gases from energy production14, the release of antibiotics used during production15, or the depletion of environmentally rich zones16 (please refer to Chapter 5). Several mechanisms and policies encourage pollution reduction. The classic economic tools available for the public sector (or government) are the imposition of taxes aimed at discouraging certain behaviours. For example, fuel consumption or pollutant emissions and the use of economic incentives, such as fiscal reductions or subsidies, are aimed at encouraging certain behaviours that have a positive impact on the desired outcome, such as the promotion of renewable energies or the adoption of new technologies with higher environmental performance. The true challenge of public policy development toward aquaculture sustainability is finding the balance between environmental protection and production increase since this combination is the sole objective of the government as it creates jobs, improves food security, and pushes economic growth while protecting the environment, making sure that (a) the industry will be sustainable in time and (b) future generations will have at least the same opportunities as we have today, which is the final objective of sustainability. 7.8.3  Social economic tools

When it comes to the economy and its influence on us, we tend to feel a little unprotected. As consumers, we are bound to the power of the industry and the choices we have available. It is common to often feel that nothing can be done as consumers

Economics and its relationship with aquaculture  109 and that we do not have the power to change the industry and push it toward sustainability. However, it is not entirely true; apart from political options, like voting in a democracy or asking representatives to do something about a specific topic, such as aquaculture and its sustainability, some economic tools are at our disposal to push the industry toward sustainability, and the main one is by using something known as “the power of the consumer”. 7.8.3.1  The power of the consumer

The supply and demand curves (Figure 7.1) show the shifts in the quantity of a product produced depending on the behaviour of two curves, supply and demand. We have discussed what happens to the supply side of the curve when there are shocks in the value chain, and the truth is that the aquaculture industry is the one that has the power to shift this curve, but the market is also driven by the demand curve which is influenced mostly by the consumer. As consumers, we have the power of choice, and that choice can affect the way companies do business. For example, a supermarket has two options for the same seafood, one is a generic product that costs 2 USD per kg, and the second one is a brand that proves their compromise with sustainable production (with certification or a new technology that allows for more information) and costs 2.3 USD per kg. As consumers, we have the choice to prefer the certified brand over the generic one, even if there is a price premium. In this manner, we are letting the market know that there is a preference for sustainability, even if it costs a little more17. In the end, if consumers opt for sustainable aquaculture products, the farms that do not follow this lead will ultimately be pushed to either adapt to the new production methods or perish and close the business due to the lack of demand. One of the main disadvantages of this strategy and tool is the assumption that all consumers have the financial capacity to buy the brand of their choice. The reality is that, primarily in developing and under-​developed countries, consumers do not have the financial liberty of choice, and either they get the generic product or do not get anything at all, even if they have strong favouritism towards sustainable production. This situation opens the door for the existence of both products. Other economic tools are available for all the components of the value chain, but it is important to emphasise that no single tool is enough to achieve a more sustainable aquaculture. It is the combination of all tools in different chain strata that will ultimately take aquaculture closer to a sustainable path. 7.9  Final remarks Economics is one of the pillars of sustainability and is often overlooked by technology and policy developers, usually due to a lack of understanding of how all the components of the industry that concern sustainability interlink, and the necessity of all of them to flourish to attain sustainable production.

110  Daniel Peñalosa Martinell Both micro-​and macroeconomics are relevant to the sustainability of aquaculture at different levels. In the case of macroeconomics, the flux of inputs and outputs through the globe affects the overall production of the industry which, in turn, impacts the livelihoods and wellness of individuals as well as the productivity, food security, and in some cases the gross domestic product of a nation. On the other hand, microeconomics will be a useful analytical tool to determine the viability of a farm as well as the areas of opportunity. A microeconomic analysis is a powerful tool to optimise processes and improve the financial performance of a farm which, in turn, could result in the sustainability of that business, its growth, and the impact on its community. It is also important to remember that the economy is not a self-​governed law of nature but a social construct. This means that we can shape and stir it towards a desired outcome. The different objectives, restraints, and methods to achieve the proposed goals give place to the different economic schools of thought. Usually, there is no right or wrong when it comes to following a specific economic school of thought, but how it is established, the areas where the focus is set by decision-​makers, and the methods followed to get to that goal along with the current social universal values and views of the world will determine its success and sustainability. 7.10  Chapter review questions 1. How would you describe the relationship between supply and demand and how does this affect the price of a product in a perfectly competitive market? 2. How is the economy related to the environmental impacts of aquaculture? 3. If you were a decision-​maker in charge of the world aquaculture industry, which tools would you use to secure aquaculture sustainability and why? 4. How does the tragedy of the commons affect aquaculture? 5. What is the difference between environmental economics and ecological economics? Recommended readings Costanza, R., Cumberland, J. H., Daly, H., Goodland, R., Norgaard, R. B., Kubiszewski, I., & Franco, C. (2014). An Introduction to Ecological Economics. CRC Press. Dixit, A. (2014). Microeconomics: A Very Short Introduction. OUP Oxford. Engle, C. R. (2010). Aquaculture Economics and Financing: Management and Analysis. John Wiley & Sons. Geissdoerfer, M., Savaget, P., Bocken, N. M., & Hultink, E. J. (2017). The Circular Economy–​ A new sustainability paradigm?. Journal of Cleaner Production, 143, 757–​768. Hanley, N., Shogren, J., & White, B. (2019). Introduction to Environmental Economics. Oxford University Press. Jolly, C. M., & Clonts, H. A. (2020). Economics of Aquaculture. CRC Press. Pindyck, R. S., & Rubinfeld, D. L. (2014). Microeconomics. Pearson Education. Thomas, A. M. (2021). Macroeconomics: An Introduction. Cambridge University Press.

Economics and its relationship with aquaculture  111 Box 7.1  Economics of aquaculture –​a case study: The mussel in Galicia Fernando Gonzalez Laxe University of Coruña, Spain Galicia, a Spanish Atlantic region, is the leading European producer of mussels (Mytilus galloprovincialis) and the third in the world, after China and Chile. Its extractions account for 95.7% of the Spanish total aquaculture production by weight, registering a high degree of both productive and geographical specialisation. Therefore, it contributes to forming the economic base of many coastal towns and serving as an income stream for many employed in this activity. Its cultivation started in the 1950s, through the installation of floating devices (called “bateas” or rafts). Production cycles consist of 14–​18 months including the phases of seed collection, stringing (attaching the seed to the string), unfolding, fattening, and final harvest. Currently there are 3,338 rafts that employ 7,141 people. In 2019, the production amounted to a total of 255,513,987 kilograms with a total value of 111,869,417 euros. These figures represent 59% of the total aquatic production in Galicia and 16% of the income of the sector, constituting one of the economic activities of reference in the region. Despite fluctuations in production, the average extraction over the last 13 years (2007–​2019) was 231,120 tons. The different oscillations were due to the appearance of “red tides” and conflict between producer organisations. Most of the rafts are family-​owned and present a low level of concentration. However, this level of concessions hoarding varies depending on the areas. In the Ría de Arousa, where 68% of the rafts are located, the ratio is 1.45 rafts per owner, while the Ría de Ares amounts to 14.7 rafts per owner, highlighting the existence of a powerful business group. Prices have shown great stability, standing at around €0.55 kg–​1, much lower than those found in Europe (€1 kg–​1). The estimated income for each raft amounts to €100,000 year–​1, which constitutes the basic element that generates income for families located in coastal towns. The use of production is distributed between demand for fresh consumption in the markets (around 65%) and the rest (35%) destined for the canning industry (Figure 7.2). Prices show a notable difference for fresh consumption (€0.46 kg–​1) and for canning (€0.40 kg–​1). Consumption shows a slight increasing trend in both headings (Spanish consumption is 1.1 kg per capita, representing 8% of the preferences for fish demand and assuming an annual expenditure of €2.8 per capita). In recent years, the Chilean mussel (Mytilus chilensis) has entered the canning industry market thanks to notable import flows. These purchases from abroad have produced a reaction in favour of the local product and the reinforcement of the Designation of Origin role. Among the weaknesses of the mussel industry is the excessive atomisation and dispersion of the

newgenrtpdf

112  Daniel Peñalosa Martinell

Figure 7.2 An example of the mussel value chain of the fresh mussels market in Galicia, Spain.

Economics and its relationship with aquaculture  113 farms, as well as the scarce coordination between public policies and scientific recommendations. The current threats are growing international competition and internal conflict among the producers. The strengths are based on the natural conditions of the estuaries, the strong social roots of the activity in the coastal areas and the growing opening of markets as there is an increase in demand given the nutritional characteristics of the product. Hence, the opportunities are concentrated in increases in consumption, and in a greater international presence based on differentiation and traceability certifications, whose features make possible the strong multiplier effect relative and inherent to exploitation, industrialisation, distribution, and product consumption. Notes i Calculated from FAO’s value data set obtained at: www.fao.org/​fish​ery/​sta​tist​ics-​query/​ en/​aqua​cult​ure/​aquacu​ltur​e_​va​lue, and China’s reported agricultural GDP, obtained at www.stats.gov.cn/​engl​ish/​Press​Rele​ase/​202​201/​t20220​113_​1826​284.html. ii An economic agent is defined as a person, company, or organisation that has an influence on the economy by producing, buying, or selling.

References 1 Hirschauer, N., Lehberger, M., & Musshoff, O. (2015). Happiness and utility in economic thought—​Or: What can we learn from happiness research for public policy analysis and public policy making?. Social Indicators Research, 121, 647–​674. 2 Daly, H. (2013). A further critique of growth economics. Ecological Economics, 88, 20–​24. 3 Curtis, S., Shabb, K., & Libertson, F. (2021). Degrowth: Challenging infinite growth in a finite world. https://​sou​ndcl​oud.com/​iiiee​podc​ast/​degro​wth 4 Mastini, R., Kallis, G., & Hickel, J. (2021). A green new deal without growth?. Ecological Economics, 179, 106832. 5 Wang, Y., & Wang, N. (2021). Exploring the role of the fisheries sector in China’s national economy: An input–​output analysis. Fisheries Research, 243, 106055. 6 FAO (2022). The State of World Fisheries and Aquaculture (SOFIA). Series number. 2022. Publisher. FAO. 7 Hardin, G. (1968). The tragedy of the commons: the population problem has no technical solution; it requires a fundamental extension in morality. Science, 162(3859), 1243–​1248. 8 Ciriacy-​Wantrup, S. V., & Bishop, R. C. (1975). “Common property” as a concept in natural resources policy. Natural Resources Journal, 15(4), 713–​727. 9 Okun, Arthur M. (2015). Equality and Efficiency: The Big Tradeoff. Brookings Institution Press. Originally published in 1975. www.jstor.org/​sta​ble/​10.7864/​j.ctt​ 13wz​tjk 10 Stiglitz, J.. People, Power, and Profits: Progressive Capitalism for an Age of Discontent. Penguin, London, UK, 2019. 11 Alcott, B. (2005). Jevons’ paradox. Ecological Economics, 54(1), 9–​21.

114  Daniel Peñalosa Martinell 12 Béné, C., Arthur, R., Norbury, H., Allison, E. H., Beveritge, M. C. M., Bush, S., Campling, L., Leschen, W., Little, D., Squires, D., Thilsted, S. H., Troell, M., Williams, M. (2015). Contribution of Fisheries and Aquaculture to Food Security and Poverty Reduction: Assessing the Current Evidence. World Development, 79, 177–​196. 13 Neiland, A. E., Soley, N., Varley, J. B., & Whitmarsh, D. J. (2001). Shrimp aquaculture: Economic perspectives for policy development. Marine Policy, 25, 265–​279. 14 Peñalosa-​Martinell, D., et al. “Probiotics as environmental performance enhancers in the production of white shrimp (Penaeus vannamei) larvae.” Aquaculture, 514 (2020): 734491. 15 Liu, X., Caleb Steele, J., and Meng, X.-​Z. (2017). “Usage, residue, and human health risk of antibiotics in Chinese aquaculture: a review.” Environmental Pollution, 223: 161–​169. 16 Malathi, M., and Rajakumari, S. (2019). “Review of depleting coastal resource areas in GODAVARI delta upon human interventions, Andhra Pradesh.” Journal of Coastal Conservation, 23(3): 543–​551. 17 Whitmarsh, D., and Wattage, P. (2006). “Public attitudes towards the environmental impact of salmon aquaculture in Scotland.” European Environment, 16(2): 108–​121.

8 Aquaculture and fisheries Fernando Aranceta Garza

In today’s industrial landscape, no industry is disconnected from the rest of the world’s economy. Aquaculture is not an exception, but not only that, as opposed to other industries, aquaculture’s growth and sustainability are intimately linked with other production systems, especially agriculture, and fisheries. In this chapter, we will deepen the discussion into the connections that bind aquaculture’s growth and sustainability to fisheries. We will explore the strong connection between both and evaluate the avenues for future research and improvement to increase aquaculture’s self-​sustainability. Finally, a reflection on the impact of the closure of the high seas on fishing and its potential consequences for aquaculture is included in Box 8.1. 8.1 Introduction Fisheries and aquaculture are key productive and interconnected sectors contributing to global food security. They represent essential and low-​cost sources of protein and nutrition, particularly in low-​income countries (e.g., in Africa)1. As discussed in earlier chapters, the production supplied in metric tons (MT) by aquaculture has exceeded total wild marine production (with a relative share of >50%) represented in most commercial taxonomic groups, such as crustaceans, molluscs, macroalgae, and fin fishes2. This aquaculture production advantage is related to the wild production stagnation associated with maximum sustainable yield status for most fishing stocks and the increasing overexploitation due to suboptimal management schemes in some countries. As a unique solution for marine food production, marine aquaculture or mariculture presents complexities related to its dependence on the ecosystem’s health to spatial sharing with other economic activities, e.g., fisheries and tourism3,4. Mariculture operation produces externalities (i.e., every external effect caused by individual users but not included in their accounting system) to the environment, the users, and the natural populations. For these reasons, its global expansion is a cause for concern due to the uncertainty in the ecological and socioeconomic implications for the fishing sector. One of the main risks related to mariculture expansion in developing countries is the weak regulations and poor management of DOI: 10.4324/9781003174271-11

116  Fernando Aranceta Garza the activity (e.g., pollution, escapes of exotic species, disease outbreaks), resulting in ecosystem deterioration and low resilience of natural populations, threatening livelihoods and food sources in coastal populations5. Furthermore, installing mariculture facilities in traditional fishing grounds causes competition and social distress for spatial, biological, and environmental resources between sectors, which are exacerbated when there is no spatial management5. Aquaculture effects on fisheries and the ecosystem will depend on the species farmed (i.e., fed vs. unfed species), the farming methods employed (pond, cage, raft, line), level of scale and intensity of farming, location of the farm (land, shore, inshore, offshore), and also the types of fisheries in the area and the level of regulation and governance of the system. Some of the most common long-​ term additive adverse effects from aquaculture to fisheries are disease outbreaks, habitat/​water quality degradation, reduced genetic fitness, overharvesting, invasive species, and price competition6. Among the positive effects are applying stock enhancement programmes, water quality improvement, and protecting populations by generating no-​fishing zones. In several countries, public social policies aim to avoid economic damage to all resource users, such as artisanal fishers, ultimately limiting aquaculture operations to a scale below their productive potential7. In other countries, public policy focuses on internalising the costs of environmental and stock externalities from mariculture (i.e., farming of marine species in the ocean, in coastal saltwater ponds, or saltwater tanks on land) to compensate other users for any economic damage. According to the above, aquaculture and wild fisheries interactions involve ecological and socioeconomic interrelationships6,7. The former refers to any effect produced by aquaculture over the fishery target species and the ecosystem, directly impacting the population dynamics of the target fishery species (e.g., exotic species, diseases, reduction fisheries for food of cultured species); and indirectly affecting the habitat of the target fishery species diminishing their populations (e.g., alteration in physicochemical parameters of the water body, chronic deterioration of the habitat). The socio-​ecological interactions directly affect fishery activities and livelihoods, resulting in economic loss and social conflicts from the exclusion of traditional fishing grounds and market competition. 8.2  Ecological interactions Ecological interactions create positive or negative externalities over the ecosystem in a dimension of space, time, and environmental uncertainty. Factors such as the scale of marine production systems, the type of species cultivated, and the intensity of cultivation are key elements that modify the level of ecological interaction. According to Clavelle5, ecological interactions include habitat modification, inputs derived from wild fish as feed for farmed species, exotic species, and transmission of diseases and parasites. Also, other interactions arise from capture-​based aquaculture (or sea ranching) and stock enhancement programmes from the release of seedlings produced in aquaculture hatcheries (Table 8.1).

newgenrtpdf

Table 8.1 Ecologic interactions between mariculture and wild fisheries and the type of effect on the ecosystem Ecological interactions 1. Habitat modification Categories a) Habitat conversion

Type of effect (–​) (–​)

b) Creation of artificial habitats and de facto no-​fishing zones

(–​) (+​) (+​)

c) Water quality

(–​) (+​)

(–​) (+​)

(Continued)

Aquaculture and fisheries  117

(–​)

Comments Habitat modification by including mariculture structures or land-​based facilities. Mainly affects mangroves, seagrasses50, and coral reefs51. Shading of structures causes competition among wild photosynthesising organisms for space. Reduction of the traditional fishing grounds and agglomeration of fishing effort with higher pressure on the resources. Mariculture influences abundance, marine community, and species residence time, generating a similar effect of a fish aggregation device (FAD) with economic benefits associated with a lower fishing effort. Similar to a marine protected area (MPA) due to restricted access with possible benefits to fishing grounds by a spillover effect, but relative to the locality, size of operation, rate of movement of wild species, and habitat status of neighbouring fishing grounds. Alteration of the nutrient cycle is caused by water discharges with food waste, excreta, dead organisms, and even antibiotics. In extreme cases, it could also cause red tides. In some cases, the contribution of nutrients to oligotrophic environments functions as fertiliser for the photosynthetic producers, promoting biodiversity and increasing catches52. Destruction of mangrove and seagrass systems in estuarine environments causes detriment to the water quality of the system, in addition to affecting nursery sites for several important commercial species. Mass production of filter-​feeding molluscs may cause recruitment failures by direct predation on planktonic larvae or control primary productivity over local species affecting higher trophic levels53. Large-​scale mariculture of filter-​feeding molluscs reduces the eutrophication of polluted water bodies54.

newgenrtpdf

2. Wild fish inputs Categories a) Aquafeeds input

Type of effect (–​)

b) Seeding

(–​) (–​) (+​)

3. Aquaculture escapement

Type of effect (–​) (+​) (–​)

4. Disease transmission

Type of effect (–​) (–​)

Comments In addition to minor pelagic species, low-​value species are incorporated into the fishmeal diet, deteriorating fish communities and biodiversity, and affecting the entire ecological fishery system55. Capture-​based aquaculture and stock enhancement programmes can increase fishing pressure and mortalities on the fishing stocks. Non-​regulated hatchery-​based practices, including stock enhancement and recovery programmes, will result in genetic deterioration, loss of fitness, increased natural mortality, and loss of biomass for fisheries56. Captive-​bred juveniles seeding into the wild will rescue populations from deteriorated population levels. Comments In cases where similar farmed and wild species coexist, and the farmed species escape, these will compete for resources where the farmed species are more aggressive and may affect the wild species. Similar farmed species escapees will compete more aggressively for resources with natural populations. Genetically modified or transgenic species put at risk the wild population gene pool with their interbreeding and alter their survival by being a dominant competitor. Comments Introducing local or exotic diseases and parasites to the environment has a detrimental impact on wild populations, reducing commercial catches. Antibiotic discharges create locally resistant microorganisms, increasing their virulence and affecting wild populations57.

118  Fernando Aranceta Garza

Table 8.1  (Continued)

Aquaculture and fisheries  119 8.2.1  Habitat modification

Habitat modification can occur through habitat conversion, the production of new (artificial) habitats, spatial access restriction, and modification of water quality6. Mariculture can modify commercial fishing species’ distribution and density/​ abundance. Land-​based aquaculture facilities, such as fish tanks or ponds for crustaceans, including shrimp farming, can destroy coastal habitats and alter water properties by discharging wastes, nutrients, microorganisms, and antibiotics (e.g., Ecuador, Mexico, Asia)8. By zonation, the mariculture impact on the intertidal zone may include baskets or corrals to cultivate oysters or other molluscs competing for space, transmitting diseases and exotic species to local communities9. In the subtidal zone, cages, buoys, anchors, and ropes with organisms may change the local hydrodynamics, alter coral reefs, and create a shading effect affecting photosynthetic organisms such as seagrasses and other macroalgae10. On the other hand, access restrictions to some mariculture areas may produce the effect of a marine protected area (MPA), where the local population may thrive and produce a spillover effect on the fishing grounds11. 8.2.2  Aquafeeds input

Many species produced by aquaculture depend on the capture fisheries, mainly reduction fisheries, as a raw material source for fishmeal and fish oil required in aquafeeds. Both elements are essential components of compound feeds, particularly for high-​value carnivorous species, where 64% of fishmeal and fish oil used in aquafeeds can come from fisheries12. Traditionally, fish meal and oil came from discarded parts of fisheries (i.e., trimmings) or fish bycatch, representing 25–​35% of compound feeds13. But the rest is from the small pelagic fisheries (also called reduction fisheries). Several small pelagic species (e.g., sardines, anchoveta, mackerel, and blue whiting) were traditionally used for reduction14. Currently, Asian fisheries are including other fish species as reduction fisheries which are considered “trash” species because of their low market value. They are inputs for aquafeeds and fertilisers, resulting in cheaper fishmeal and causing potentially profound negative ecosystemic consequences15. Limited supplies from reduction fisheries and increasing fish meal and fish oil prices have motivated a reduction in aquaculture dependency on fish meals. Most fish meals are replaced by vegetable proteins such as soy16. Also, alternative substitute products, besides fishmeal, are being analysed to be included in aquafeed compositions using a balance of dietary amino acids17. Finally, the potential impacts of reduction fisheries on ecosystems need to be further considered and studied. Most of these fisheries continue to target low-​ trophic-​level species, some potentially critical to the large marine ecosystems on which many marine (fish, cartilaginous fish, marine mammals) and terrestrial (seabirds) species depend for survival. National policies should adopt ecosystem-​ based fisheries management to regulate small pelagics reduction fishery and

120  Fernando Aranceta Garza continued aquaculture innovation for substitute aquafeed products. Because of these implications, these ecological considerations in fisheries management are embodied in the sustainability certifications of this type of fisheries (e.g., MSC, Marin Trust). 8.2.3  Aquaculture escapements

Cultured organisms escape to the wild in two ways, the first is by direct escaping, and the other is by spawning into the environment. The main cause of the former is a technological failure in the farm infrastructure (broken tanks, nets, or cages), impact from climatic events such as storms, floods, and human error due to poor management practices. Most escapes are seldom eliminated from the ecosystem18, and they will compete with wild individuals for essential resources. The reared individuals may exhibit aggressive behaviours associated with tank crowding and food competition, increasing the natural mortality rate of the local population and affecting the biomass available for fisheries. Moreover, if they are evolutionarily close species, interbreeding could cause homogenisation and loss of genetic fitness19. This situation has already been documented in salmon species in Norway, North America, and Ireland20,21. 8.2.4  Exotic species

Introducing exotic species (i.e., species outside their natural distribution range) to a new natural environment by aquaculture handling may result either in a no-​effect event or an ecosystem invasion when the new colonisers outperform local species19. A well-​studied example is the successful invasion of the Japanese oyster (Cassosstrea gigas)22 in North America and Europe. Other invasive species can be genetically modified to enhance specific biological features, such as growth or disease resistance. These represent a hazard to natural populations by interbreeding to transgenic hybrids (i.e., production of an organism of one species into which one or more genes of another species have been incorporated), characterised as a dominant competitor over wild and cultivated non-​transgenic species, representing a potential ecological and economic risk to wild fisheries23. In some cases, genetically modified organisms are sterile triploid organisms (three sets of chromosomes) with higher growth rates. This technique is frequently applied in molluscs24. 8.2.5  Disease transmission

Diseases and parasites in cultured marine organisms can be local or exotic and represent the leading cause of massive losses in the world aquaculture industry. Their transmission to wild commercial populations can have severe ecological and economic consequences25. However, the effect at the population level is still under continuous research26. In cases where natural populations are genetically

Aquaculture and fisheries  121 compromised by inbreeding (i.e., small populations or interbreeding with aquaculture escapees), disease transmission from culture individuals can contribute to comprise population dynamics27. The introduction of non-​native diseases/​parasites by the transport of organisms around the world is very common, such as the case of disease transmission in Pacific oysters (C. gigas) between Japan and America and then with oysters of another species in the Atlantic (C. virginica)28. Another example of global disease transmission is the case of the white shrimp (Litopenaeus vannamei) and white spot disease (WSD), Taura syndrome, and yellowhead disease in Asia, America, and Europe29. In the same way, the application of antibiotics to cultured diseased fish has led to antibiotic residue accumulation in the culture areas and adjacent habitats, which enhances the proliferation of antibiotic-​resistant genes, altering the microbial communities and biogeochemical cycles, representing a risk to animal and human health. Currently, the use of antibiotics in farmed animals is banned in some developed countries. However, the indiscriminate use of antibiotics is relatively high among major producing countries such as in Asia and other developing countries30. 8.2.6  Enhanced fisheries and capture-​based aquaculture

Another interaction between commercial fisheries and mariculture occurs with capture-​based aquaculture and by enhancing wild fish stock through seedling liberation. In the first case, juvenile fish (fingerlings, fry, seedlings), bivalve molluscs (spats), or algae are captured from the environment and stocked in farm cages, where they are reared; this is also known as sea ranching31. In contrast, stock enhancement programmes depend on producing larvae from the laboratory by selecting domesticated mature individuals and seeding in the surrounding environment. The primary interaction of capture-​based aquaculture with wild fisheries is the competition for different population components of the species, similar to a sequential fishery. Both fleets’ fishing mortalities increased fishing pressure on the stock, but usually, stock assessments omit the sea ranching fleet, which may bias the evaluation results32. In the case of the stock enhancement programmes, poor genetic selection of adult organisms can cause a drop in the fitness of wild organisms. Furthermore, frequently, adult selection is biased towards enhancing profitability characteristics, i.e., higher growth or muscle quality33, not to equalise genetics with natural populations. 8.3  Socioeconomic interactions The coastal and offshore marine zone is shared by several economic actors, including artisanal fishermen, industrial fishermen, sport fishermen, mariculturists, and even tourism service providers. Mariculture can generate

122  Fernando Aranceta Garza externalities mainly by establishing exclusive spatial use rights or access limitations; and market competition when two similar or substitute products (wild vs. aquaculture) affect the supply and prices of the production at the local, regional, or global level34. Private mariculture concession creates de facto spatial zones restricted to fishing, reducing traditional fishing grounds. These zones may act as small MPAs producing spillovers to the surrounding fishing zones, but their effect is relative to the size of the concession, the type of species, and the surrounding habitat35. Furthermore, spatial restriction affects free navigation and promotes competition between farm and commercial fishers for wild catches. Similarly, land-​based aquaculture concessions (shrimp or fish) can displace traditional landing zones causing social conflicts with artisanal fishers. The market for marine products changes according to global demand and supply. As a result of the expansion of aquaculture, the demand for farmed seafood and wild-​fish food inputs has increased, resulting in a greater supply of seafood products affecting farm-​gate and ex-​vessel prices, less price volatility, and greater resilience36. Likewise, the increased demand for catches from reduction fisheries (catches aimed to feed farmed animals) can affect ecosystem trophic relations (in the case that the fishery is not properly managed) and the biomass of wild populations, impacting fishing landings. Decreasing prices will affect the least resilient or less efficient competitor, usually the fishing fleet, because of the hardship in covering their operational daily unit costs. However, market preferences serve as a regulatory factor in the demand for seafood products, playing a fundamental role in consumer selection and affecting the demand curve. For example, consumers in Canada or the European Union prefer wild, certified fresh products over cultured products, potentially being able to pay a premium for a wild fishery product37. In cases where aquaculture production is based on foreign investment, such as in Africa38, they will affect the income and profitability of wild landings. In order to compensate for the externalities caused by foreign capital farms (i.e., environmental impacts, competition for space, and imperfect market competition), a corrective tax (called Pirugvian tax) could be applied to compensate for the economic damage caused by their activities to local fishermen (Table 8.2). 8.4  Future trends for fisheries and mariculture Given the interactions mentioned above and the subsequent effects between wild fisheries and aquaculture, national agencies and governments should work towards policies that encourage holistic management of the marine production systems under an ecosystem approach based on property rights and spatial planning. Establishing property rights over common resources (i.e., commercial species or marine spatial concession) encourages stewardship, increases operation efficiency, reduces costs, and buffers against falling prices39. However, in many developing countries, the establishment of property rights is not clear or absent, causing social

newgenrtpdf

Table 8.2 Socioeconomic interactions between mariculture and wild fisheries and the type of effect on the ecosystem Socioeconomic interactions 1. Spatial exclusion Categories

2. Market competition Categories

Comments Aggregation of fishing effort in reduced areas and increased fishing pressure on resources. A no-​fishing area is similar to an MPA, where resident populations may create a spillover effect to the reduced fishing grounds.

Type of effect (+​)

Observations Market preferences for wild, fresh, and certified products on a sustainable basis lead to better management. With the expansion of aquaculture, pressure on reduction fisheries for farmed fish feed increases. An increased supply of farmed or wild substitutes decreases prices and negatively impacts fish landings.

(–​) (–​)

Aquaculture and fisheries  123

Type of effect (–​) (+​)

124  Fernando Aranceta Garza conflicts between productive sectors. Under the property rights scheme, an economic compensation system can be established to account for the damage or economic losses derived from the externalities of other activities, such as mariculture space restriction or pollution, towards fisheries46. In the case of an open-​access fishery (without any regulation or property rights), the state of overexploitation and loss of economic profitability of the fishery, together with the expansion of aquaculture (i.e., increased supply), will cause a fall in the market prices, forcing units of fishing effort out of operation, which may lead to stock recovery but under financial hardship for fishers40. On the other hand, rights-​based fisheries management of spatial marine resources, called TURF (Territorial Use Rights for Fisheries), allows the sustainable coexistence of both activities, where holistic management and continuous evaluation of ecosystem indicators will be pivotal for achieving sustainable objectives (i.e., biological, socioeconomic, ecosystemic) so that communities can make decisions on the intensity and allocation of mariculture and fisheries. Comprehensive marine spatial planning (MSP) evaluates the spatial distribution of marine users towards ecological, economic, and social objectives4, and is already applied in Europe, New Zealand, Australia, Ecuador, and Chile41. MSP is essential in managing productive activities over the seascape focusing on maximising social benefit and reducing externalities among users and ecosystems42. Likewise, spatial planning considers the allocation for aquaculture, the type of specie cultured, the diversity of farming methods, and the ecological and environmental conditions of the culture area, including alignment with other activities, such as local fisheries. In productive terrestrial systems, crop heterogeneity promotes biological diversity and reduces disease risk and crop failure. In marine systems, most large-​scale and high-​density fish farming operations are mono-​specific and highly susceptible to mortalities caused by diseases; adapting spatial planning to include heterogeneous species farming could ameliorate farming disease outbreaks, including their transmission to wild populations. 8.5  Final remarks Fisheries and aquaculture represent critical sources of food security, employment, and livelihoods for millions of persons. Their importance has increased recently as land-​based production lags due to complexities such as space restrictions, freshwater availability, pollution, climate change, and increasing urban areas. In contrast, mariculture is expanding to oceans worldwide, becoming a future primary food source. However, wild fisheries and mariculture production cannot cover the other sector’s production, so any negative interactions between them or their surrounding environment will affect future food availability. Therefore, national policies must direct efforts towards aligning mariculture and wild fisheries aiming for holistic and sustainable management, considering property rights and an ecosystemic approach, maximising their social value, and minimising the environmental cost to the wild resources (Box 8.1).

Aquaculture and fisheries  125 8.6  Chapter review questions 1 Describe the relationships that exist between wild-​caught fisheries and aquaculture. 2 What is the main bottleneck for the sustainability of fed aquaculture and how does that affect the wild fisheries sector? 3 In your opinion, is capture-​based aquaculture sustainable? What about enhanced fisheries? 4 From a market perspective, what relationship exists between fisheries and aquaculture, and how are each of these industries affected?

Recommended readings Asche, F., Dahl, R. E., & Steen, M. (2015). Price volatility in seafood markets: Farmed vs wild fish. Aquaculture Economics & Management, 19(3), 316–​335. https://​doi.org/​ 10.1080/​13657​305.2015.1057​879 Clavelle, T., Lester, S. E., Gentry, R., & Froehlich, H. E. (2019). Interactions and management for the future of marine aquaculture and capture fisheries. Fish and Fisheries, 20(2), 368–​388. Gentry, R. R., Lester, S. E., Kappel, C. V., White, C., Bell, T. W., Stevens, J., & Gaines, S. D. (2017). Offshore aquaculture: Spatial planning principles for sustainable development. Ecology and Evolution, 7(2),733–​743. https://​doi.org/​10.1002/​ece3.2637 Johansen, L.-​H., Jensen, I., Mikkelsen, H., Bjørn, P.-​A., Jansen, P. A., & Bergh, Ø. (2011). Disease interaction and pathogens exchange between wild and farmed fish populations with special reference to Norway. Aquaculture, 315(3–​4), 167–​186. https://​doi.org/​ 10.1016/​j.aqua​cult​ure.2011.02.014 Machias, A., Giannoulaki, M., Somarakis, S., Maravelias, C. D., Neofitou, C., Koutsoubas, D., & Karakassis, I. (2006). Fish farming effects on local fisheries landings in oligotrophic seas. Aquaculture, 261(2), 809–​16. https://​doi.org/​10.1016/​j.aqua​cult​ ure.2006.07.019 Natale, F., Hofherr, J., Fiore, G., & Virtanen, J. (2013). Interactions between aquaculture and fisheries. Marine Policy, 38, 205–​213. https://​doi.org/​10.1016/​j.mar​pol.2012.05.037 Olsen, R. L., & Hasan, M. R. (2012). A limited supply of fishmeal: Impact on future increases in global aquaculture production. Trends in Food Science & Technology, 27(2), 120–​128. Ottolenghi, F., Silvestri, C., Giordano, P., Lovatelli, A., & New, M. B. (2004). Capture-​ Based Aquaculture: The Fattening of Eels, Groupers, Tunas and Yellowtail. Rome, Italy: Food and Agriculture Organization of the United Nations Peñalosa Martinell, D., Cashion, T., Parker, R., & Sumaila, U. R. (2020). Closing the high seas to fisheries: Possible impacts on aquaculture. Marine Policy, 115, 103854. Shannon, L., & Waller, L. (2021). A cursory look at the fishmeal/​oil industry from an ecosystem perspective. Frontiers in Ecology and Evolution, 9, 645023. Valderrama, D., & Anderson, J. L. (2010). Market interactions between aquaculture and common-​property fisheries: Recent evidence from the Bristol Bay sockeye salmon fishery in Alaska. Journal of Environmental Economics and Management, 59(2), 115–​ 128. https://​doi.org/​10.1016/​j.jeem.2009.12.001

126  Fernando Aranceta Garza Box 8.1  How would closing the high seas to fishing impact aquaculture? Ussif Rashid Sumaila The University of British Columbia, Canada Because of anticipated increases in both global population and wealth, the consumption of seafood has been rising rapidly over the past few decades. Since wild-​capture fisheries harvests have probably peaked or nearly peaked, any considerable expansion in the supply of fish in the future is anticipated to mostly come from aquaculture.43 However, by employing fishmeal and fish oil to sustain the culture of fed species, aquaculture continues to rely on wild supplies. Recently, there have been requests for the high seasi (HS) to be off-​limits to fishing due to worries about wild fish populations. Furthermore, this closure would increase future catches while temporarily reducing current catches of marine species. In this case, we present the possible effects of banning fishing in the high seas on marine fish capture that is processed into fishmeal and fish oil and its possible impacts on global aquaculture. It is estimated that these adjustments may affect the cost of fishmeal and the profitability of the worldwide aquaculture sector. Overall, research indicates that the effect of banning fishing on the high seas on aquaculture is probably not very large.44 Most reduction fisheries activities take place within the Exclusive Economic Zoneii; nonetheless, some activity is still undertaken on the high seas, mainly in South America, Mexico, and the northwest Pacific Ocean. Since more than 90% of the catches come from the EEZ, it can be expected that the closure of the HS to fisheries would have a very small impact on the overall production of fishmeal. Even though the impact on the amount produced can be small, there is still a potential effect observed on prices due to reduced access to raw materials. This effect is somewhat similar to what is observed with an increase in aquaculture production (due to higher demand). The expected effects of the closure of HS to fishing on aquaculture profits are highly variable and depend on the species produced and the production methods. In general, high-​value species like salmonids and marine shrimps are expected to be more affected, which is unsurprising given their consumption of fishmeal. Species like tilapia and carp, which are less valuable but more relevant to global seafood security, would see no important changes in profits since they have less dependence on fishmeal and can substitute this ingredient more easily. Closure of the high seas may have potential impacts on sectors of the aquaculture industry beyond fishmeal inputs to feeds. Notably, species like tuna, which rely on wild capture of juveniles, will be affected by wild populations in the HS. According to Metian et al.,45 between 17 and 37 percent of bluefin tuna catches go to aquaculture. The closure of the HS may increase significantly the availability of tuna juveniles in the EEZ46,47, increasing

Aquaculture and fisheries  127 production capacity, as the availability of juvenile tuna is one of the production bottlenecks. Overall, the effects of closing the HS to fishing on aquaculture can be expected to be minimal. This, added to the expected positive effects on the fisheries industry48 and the environment49, suggests that the closure of the high seas to fisheries would globally have a positive effect, with more sustainable profits for fisheries without an important impact on aquaculture production, especially for those species that are relevant to achieve food security.

Notes i International waters, or the part of the seas that do not form part of the sovereignty of any country or group of countries. ii The Exclusive Economic Zones or EEZ is an area of the ocean, generally extending 200 nautical miles (230 miles) beyond a nation’s territorial sea, within which a coastal nation has jurisdiction over both living and nonliving resources.

References 1 Thilsted, S. H., Thorne-​Lyman, A., Webb, P., Bogard, J. R., Subasinghe, R., Phillips, M. J., & Allison, E. H. (2016). Sustaining healthy diets: The role of capture fisheries and aquaculture for improving nutrition in the post-​2015 era. Food Policy, 61, 126–​131. 2 FAO. 2021. FAO Yearbook. Fishery and Aquaculture Statistics 2019/​FAO annuaire. Statistiques des pêches et de l’aquaculture 2019/​FAO anuario. Estadísticas de pesca y acuicultura 2019. Rome/​Roma. 3 Zheng, W., Shi, H., Chen, S., & Zhu, M. (2009). Benefit and cost analysis of mariculture based on ecosystem services. Ecological Economics, 68(6), 1626–​1632. 4 Neori, A., Troell, M., Chopin, T., Yarish, C., Critchley, A., & Buschmann, A. H. (2007). The need for a balanced ecosystem approach to blue revolution aquaculture. Environment: Science and Policy for Sustainable Development, 49(3), 36–​43. 5 Clavelle, T., Lester, S. E., Gentry, R., & Froehlich, H. E. (2019). Interactions and management for the future of marine aquaculture and capture fisheries. Fish and Fisheries, 20(2), 368–​388. 6 Mikkelsen E. (2007). Aquaculture-​fisheries interactions. Marine Resource Economics, 22(3), 287–​303. 7 Knapp, G., & Rubino, M. C. (2016). The political economics of marine aquaculture in the United States. Reviews in Fisheries Science & Aquaculture, 24(3), 213–​229. https://​ doi.org/​10.1080/​23308​249.2015.1121​202 8 Hamilton, S. (2013). Assessing the role of commercial aquaculture in displacing mangrove forest. Bulletin of Marine Science, 89(2), 585–​601. 9 Solomon, O. O., & Ahmed, O. O. (2016). Ecological consequences of oysters culture: A review. International Journal Fisheries Aquatic Studies, 4, 1–​6. 10 Dumbauld, B. R., & McCoy, L. M. (2015). Effect of oyster aquaculture on seagrass Zostera marina at the estuarine landscape scale in Willapa Bay, Washington (USA). Aquaculture Environment Interactions, 7(1), 29–​47.

128  Fernando Aranceta Garza 11 Halpern, B. S., McLeod, K. L., Rosenberg, A. A., & Crowder, L. B. (2008). Managing for cumulative impacts in ecosystem-​ based management through ocean zoning. Ocean & Coastal Management, 51(3), 203–​211. https://​doi.org/​10.1016/​j.ocecoa​ man.2007.08.002 12 Shannon, L., & Waller, L. (2021). A cursory look at the fishmeal/​oil industry from an ecosystem perspective. Frontiers in Ecology and Evolution, 9, 645023. 13 Stevens, J. R., Newton, R. W., Tlusty, M., & Little, D. C. (2018). The rise of aquaculture by-​products: Increasing food production, value, and sustainability through strategic utilisation. Marine Policy, 90, 115–​124. 14 Cashion, T., Tyedmers, P., & Parker, R. W. (2017a). Global reduction fisheries and their products in the context of sustainable limits. Fish and Fisheries, 18(6), 1026–​1037. 15 Cashion, T., Le Manach, F., Zeller, D., & Pauly, D. (2017b). Most fish destined for fishmeal production are food-​grade fish. Fish and Fisheries, 18(5), 837–​844. 16 Olsen, R. L., & Hasan, M. R. (2012). A limited supply of fishmeal: Impact on future increases in global aquaculture production. Trends in Food Science & Technology, 27(2), 120–​128. 17 Gaylord, T. G., Sealey, W. M., Barrows, F. T., Myrick, C. A., & Fornshell, G. (2017). Evaluation of ingredient combinations from differing origins (fishmeal, terrestrial animal and plants) and two different formulated nutrient targets on rainbow trout growth and production efficiency. Aquaculture Nutrition, 23(6), 1319–​1328. https://​ doi.org/​10.1111/​anu.12507 18 Jensen, Ø., Dempster, T., Thorstad, E. B., Uglem, I., & Fredheim, A. (2010). Escapes of fishes from Norwegian sea-​cage aquaculture: Causes, consequences and prevention. Aquaculture Environment Interactions, 1(1), 71–​83. https://​doi.org/​10.3354/​aei00​008 19 Naylor, R., Hindar, K., Fleming, I. A., Goldburg, R., Williams, S., Volpe, J., ... & Mangel, M. (2005). Fugitive salmon: Assessing the risks of escaped fish from net-​pen aquaculture. BioScience, 55(5), 427–​437. https://​doi.org/​10.1641/​0006-​ 3568(2005)055[0427:FSA​TRO]2.0.CO;2 20 Bolstad, G. H., Hindar, K., Robertsen, G., Jonsson, B., Sægrov, H., Diserud, O. H., … Karlsson, S. (2017). Gene flow from domesticated escapes alters the life history of wild Atlantic salmon. Nature Ecology & Evolution, 1, 0124. https://​doi.org/​10.1038/​ s41​559-​017-​0124 21 Bolstad, G. H., Hindar, K., Robertsen, G., Jonsson, B., Sægrov, H., Diserud, O. H., … Karlsson, S. (2017). Gene flow from domesticated escapes alters the life history of wild Atlantic salmon. Nature Ecology & Evolution, 1, 0124. https://​doi.org/​10.1038/​ s41​559-​017-​0124 22 Herbert, R. J., Humphreys, J., Davies, C. J., Roberts, C., Fletcher, S., & Crowe, T. P. (2016). Ecological impacts of non-​native Pacific oysters (Crassostrea gigas) and management measures for protected areas in Europe. Biodiversity and Conservation, 25, 2835–​2865. 23 Dunham, R. A. (2009). Transgenic fish resistant to infectious diseases, their risk and prevention of escape into the environment and future candidate genes for disease transgene manipulation. Comparative Immunology, Microbiology and Infectious Diseases, 32(2), 139–​161. 24 Tan, K., Deng, L., & Zheng, H. (2021). Effects of stocking density on the aquaculture performance of diploid and triploid, Pacific oyster Crassostrea gigas and Portuguese oyster C. angulata in warm water aquaculture. Aquaculture Research, 52(12), 6268–​6279.

Aquaculture and fisheries  129 25 Lafferty, K. D., Harvell, C. D., Conrad, J. M., Friedman, C. S., Kent, M. L., Kuris, A. M., … Saksida, S. M. (2015). Infectious diseases affect marine fisheries and aquaculture economics. Annual Review of Marine Science, 7(1), 471–​496. https://​doi.org/​ 10.1146/​annu​rev-​mar​ine-​010​814-​015​646 26 Heuch, P., Jansen, P., Hansen, H., Sterud, E., MacKenzie, K., Haugen, P., & Hemmingsen, W. (2011). Parasite faunas of farmed cod and adjacent wild cod populations in Norway: A comparison. Aquaculture Environment Interactions, 2(1), 1–​13. https://​doi.org/​10.3354/​aei00​027 27 Johansen, L.-​H., Jensen, I., Mikkelsen, H., Bjørn, P.-​A., Jansen, P. A., & Bergh, Ø. (2011). Disease interaction and pathogens exchange between wild and farmed fish populations with special reference to Norway. Aquaculture, 315(3–​4), 167–​186. https://​ doi.org/​10.1016/​j.aqua​cult​ure.2011.02.014 28 Burreson, E. M., Stokes, N. A., & Friedman, C. S. (2000). Increased virulence in an introduced pathogen: Haplosporidium nelsoni (MSX) in the Eastern Oyster Crassostrea virginica. Journal of Aquatic Animal Health, 12(1), 1–​8. https://​doi.org/​10.1577/​1548-​ 8667(2000)0122.0.CO;2 29 Stentiford, G. D., & Lightner, D. V. (2011). Cases of white spot disease (WSD) in European shrimp farms. Aquaculture, 319(1–​2), 302–​306. 30 Wang, X., Lin, Y., Zheng, Y., & Meng, F. (2022). Antibiotics in mariculture systems: A review of occurrence, environmental behavior, and ecological effects. Environmental Pollution, 293, 118541. 31 Lorenzen, K., Leber, K. M., & Blankenship, H. L. (2010). Responsible approach to marine stock enhancement: An update. Reviews in Fisheries Science, 18(2), 189–​210. https://​doi.org/​10.1080/​10641​262.2010.491​564 32 Ottolenghi, F., Silvestri, C., Giordano, P., Lovatelli, A., & New, M. B. (2004). Capture-​ Based Aquaculture: The Fattening of Eels, Groupers, Tunas and Yellowtail. Rome, Italy: Food and Agriculture Organization of the United Nations. 33 Teletchea, F., & Fontaine, P. (2014). Levels of domestication in fish: Implications for the sustainable future of aquaculture. Fish and Fisheries, 15(2), 181–​195. https://​doi. org/​10.1111/​faf.12006 34 Natale, F., Hofherr, J., Fiore, G., & Virtanen, J. (2013). Interactions between aquaculture and fisheries. Marine Policy, 38, 205–​213. https://​doi.org/​10.1016/​j.mar​ pol.2012.05.037 35 Halpern, B. S., Lester, S. E., & Kellner, J. B. (2009). Spillover from marine reserves and the replenishment of fished stocks. Environmental Conservation, 36(4), 268–​276. 36 Asche, F., Dahl, R. E., & Steen, M. (2015). Price volatility in seafood markets: Farmed vs wild fish. Aquaculture Economics & Management, 19(3), 316–​335. https://​doi.org/​ 10.1080/​13657​305.2015.1057​879 37 Murray, G., Wolff, K., & Patterson, M. (2017). Why eat fish? Factors influencing seafood consumer choices in British Columbia, Canada. Ocean & Coastal Management, 144, 16–​22. https://​doi.org/​10.1016/​j.ocecoa​man.2017.04.007 38 Akpalu, W., & Bitew, W. T. (2018). Externalities and foreign capital in aquaculture production in developing countries. Environment and Development Economics, 23(2), 198–​215. DOI: https://​doi.org/​10.1017/​S13557​70X1​8000​025 39 Valderrama, D., & Anderson, J. L. (2010). Market interactions between aquaculture and common-​property fisheries: Recent evidence from the Bristol Bay sockeye salmon fishery in Alaska. Journal of Environmental Economics and Management, 59(2), 115–​ 128. https://​doi.org/​10.1016/​j.jeem.2009.12.001

130  Fernando Aranceta Garza 40 Anderson, J. L. (1985). Market interactions between aquaculture and the common-​ property commercial fishery. Marine Resource Economics, 2(1), 1–​24. https://​doi.org/​ 10.1086/​mre.2.1.42628​874 41 Sanchez-​Jerez, P., Fernandez-​Jover, D., Uglem, I., Arechavala-​Lopez, P., Dempster, T., Bayle-​Sempere, J. T., ... & Nilsen, R. (2011). Coastal fish farms as fish aggregation devices (FADs). Artificial Reefs in Fishery Management. CRC Press. Taylor & Francis Group, FL, USA, 187–​208. 42 Gentry, R. R., Lester, S. E., Kappel, C. V., White, C., Bell, T. W., Stevens, J., & Gaines, S. D. (2017). Offshore aquaculture: Spatial planning principles for sustainable development. Ecology and Evolution, 7(2),733–​743.https://​doi.org/​10.1002/​ece3.2637 43 Costello, Christopher, Ling Cao, Stefan Gelcich, Miguel Á. Cisneros-​Mata, Christopher M. Free, Halley E. Froehlich, Christopher D. Golden et al. (2020). The future of food from the sea. Nature, 588,7836, 95–​100. 44 Martinell, Daniel Peñalosa, Tim Cashion, Robert Parker, & U. Rashid Sumaila. (2020). Closing the high seas to fisheries: Possible impacts on aquaculture. Marine Policy 115, 103854. 45 Metian, M., Pouil, S., Boustany, A., & Troell, M. (2014). Farming of Bluefin tuna-​ reconsidering global estimates and sustainability concerns. Reviews in Fisheries Science and Aquaculture 22, 184–​192. DOI: 10.1080/​23308249.2014.907771. 46 White, C., & Costello, C. (2014). Close the high seas to fishing?. PLOS Biology 12,3. 47 Sala, E., Mayorga, J., Costello, C., Kroodsma, D., Palomares, M.L.D., Pauly, D., Sumaila, U.R., Zeller, D. (2018). The economics of fishing the high seas. Science Advances 4, 6. DOI: 10.1126/​sciadv.aat2504. 48 Sumaila, U.R., Lam, V.W.Y., Miller, D.D., Teh, L., Watson, R.A., Zeller, D., Cheung, W.W.L., Côté, I.M., Rogers, A.D., Roberts, C., Sala, E., & Pauly, D. (2015). Winners and losers in a world where the high seas is closed to fishing. Scientific Reports 5(8481), 1–​6. DOI: 10.1038/​srep08481. 49 Norse, E.A., Brooke, S., Cheung, W.W.L., Clark, M.R., Ekeland, I., Froese, R., Gjerde, K.M., Haedrich, R.L., Heppell, S.S., Morato, T., Morgan, L.E., Pauly, D., Sumaila, U.R., & Watson, R., (2012). Sustainability of deep-​sea fisheries. Marine Policy, 36, 307–​320. DOI:10.1016/​j.marpol.2011.06.008. 50 Herbeck, L. S., Sollich, M., Unger, D., Holmer, M., & Jennerjahn, T. C. (2014). Impact of pond aquaculture effluents on seagrass performance in NE Hainan, tropical China. Marine Pollution Bulletin, 85(1), 190–​203. 51 Saenger, P. (1993). Some environmental considerations in aquaculture planning and operation. In Proceedings of the First International Symposium on aquaculture technology and Investment opportunities (p. 53). Ministry of Agriculture and Water. 52 Machias, A., Giannoulaki, M., Somarakis, S., Maravelias, C. D., Neofitou, C., Koutsoubas, D., … Karakassis, I. (2006). Fish farming effects on local fisheries landings in oligotrophic seas. Aquaculture, 261(2), 809–​16. https://​doi.org/​10.1016/​ j.aqua​cult​ure.2006.07.019 53 Préat, N., De Troch, M., van Leeuwen, S., Taelman, S. E., De Meester, S., Allais, F., & Dewulf, J. (2018). Development of potential yield loss indicators to assess the effect of seaweed farming on fish landings. Algal Research, 35, 194–​205. https://​doi.org/​ 10.1016/​j.algal.2018.08.030 54 Gren, I.-​M., Lindahl, O., & Lindqvist, M. (2009). Values of mussel farming for combating eutrophication: An application to the Baltic Sea. Ecological Engineering, 35(5), 935–​945. https://​doi.org/​10.1016/​j.ecol​eng.2008.12.033

Aquaculture and fisheries  131 55 Funge-​Smith, S., Lindebo, E., Staples, D., & Fao, B. (2005). Asian fisheries today: The production and use of low value/​trash fish from marine fisheries in the Asia-​Pacific region. Retrieved from http://​agris.fao.org/​agris-​sea​rch/​sea​rch.do?recor​dID=​XF201​ 5012​256 56 Araki, H., & Schmid, C. (2010). Is hatchery stocking a help or harm?: Evidence, limitations and future directions in ecological and genetic surveys. Aquaculture, 308, S2–​S11. 57 Watts, J. E., Schreier, H. J., Lanska, L., & Hale, M. S. (2017). The rising tide of antimicrobial resistance in aquaculture: sources, sinks and solutions. Marine Drugs, 15(6), 158.

9 Aquaculture value chain analysis Daniel Peñalosa Martinell

When we think of aquaculture, the main thing that comes to mind is an aquatic farm or facility and its production, but the stakeholders involved in the aquaculture industry greatly surpass this initial picture. Therefore, what else composes this aquaculture network? After the farm or producer, the next thing we usually think about is the inputs needed to get that product and how the outputs are used and commercialised, so the next most common answer to the composition of the aquaculture network abovementioned tends to include the components of a supply chain, that is, the feed mills and other product manufacturers that provide the inputs needed for aquaculture production, the intermediaries and processors, and the final resellers of the product. Although these components are, indeed, part of the composition of the network that composes the aquaculture industry, they are only a portion of it. To fully understand this network, we need to think of all the different stakeholders that provide not only products, but value to the aquaculture industry. This value can be provided in the form of certifications, financial services, data management and analysis, legislation, or any other possible way in which the industry adds value, understanding the creation of value as maximising the value of a product in financial terms. The composition of all these stakeholders and their relationships is what we understand as a “value chain” (although it is more of a value net), and comprehending and analysing it is a powerful tool for public and private decision-​makers to better understand where value is created in the industry and the margins gained in each of the value-​creation steps. In this chapter, we will see in a very general way the composition and analysis of a value chain analysis. 9.1 Introduction A value chain analysis is a quantitative and qualitative analysis framework of a complex system composed of several actors and relationships among them. The objectives and applications of this type of analysis are varied, and the approaches by which a value chain is dealt with may be different. According to Bush et al.,5 three main conceptualisations have been given to value chains in aquaculture. DOI: 10.4324/9781003174271-12

Aquaculture value chain analysis  133 1 As an industrial organisation tool: This approach allows the evaluation, acquisition, and transformation of inputs into products and their distribution usage in other production or consumption sites. According to this conceptualisation, value chains are usually analysed in three non-​exclusive terms: a Structure: The emphasis is on the geographical location of the actors, the size, and degree of concentration among them, and the relationships between each chain node. b Conduct: This term refers to the actors’ behaviour in each production stage, their role in the processes, and the existing relationships among the nodes. c Performance: The process efficiency, product quality, or social, economic, and/​or environmental results are analysed. This is the ultimate quantitative term and allows for performing comparative analyses, and establishes markers and reference points. 2 Value chains can be used as global analysis tools to study the networks that govern coordination within and between transnational enterprises and other actors to facilitate production, commerce, and international consumption of goods and services. Since sea products are commercialised goods at a global scale, the value chain analysis with a global perspective can help to evaluate or assist transnational enterprises or leaders to study traded commodities, such as salmon, tilapia, oyster, shrimp, or other products with high consumption rates at the international level. When a global approach is performed, networks or chains should be considered to be influenced by “extra-​chain” actors, such as non-​governmental organisations (NGOs) or governments, and standards and regulations imposed. 3 Value chains can be used to achieve regulation objectives,1 such as poverty alleviation2 or gender equality,3 through technical support for process and ability for “improvement” in key nodes (maximising impact with less effort, that is, optimising the resources) or efforts to improve market access, and the terms of exchange or incorporation of the producer, workers, and other actors related to the value chain.   The value chain analysis in aquaculture products has gained interest in the last years because it gives rise to the processes that benefit in a great measure sea product marketing, allowing the application of policies destined to maximise redistribution of the profit obtained in fishing and aquaculture.4 The value chains of aquatic products have a wide interconnection with different industries and actors.5 For example, first, a follow-​up of reduction fishery is necessary for carnivore animal production that takes the product through a transformation process to turn it into fish meal and fish oil (see Chapter 8). Then, this product is linked to other ingredients to produce pellets that are used to feed organisms in aquaculture systems. At the same time, these aquaculture products are harvested and pass through another series of processes, such as freezing the primary transformations (eviscerating, descaling, beheading, etc.). Secondary transformation

134  Daniel Peñalosa Martinell (preparing, vacuum-​packaging, etc.) is performed before marketing and sending to distributors, who place them in retail shops for access to the final consumer. Moreover, a series of sub-​products and waste joins the supply chain of any other process, such as packaging waste, fish viscera, or crustacean exoskeleton. Jointly to the previous connections, different actors that have a significant effect on the products come into play. For example, the state oversees establishing the rules of action of the participants in the value chain, which can have an impact on financial aspects of production, for example through the payment of permits; non-​ governmental organisations that search, among other things, to keep watch over the good compliance of the regulations independently or consultancy or labelling service providers, just to mention some. The main objective of the value chain analysis is to assess the utilityi margins that move in the different chain links, which allow knowing and improving their distribution deriving from aquaculture production. Thus, if the greatest part of this value generated by one product stays in a chain minority, a strategy may likely allow the farms to absorb the responsibilities and maintain a portion of that margin or the state may develop rules to maximise that distribution. This type of analysis has been performed recently at a national level, both in developing countries such as Indonesia6 and Bangladesh7 and in developed countries such as Iceland8 and Singapore.9 Moreover, it has been also made at the local and species-​specific level, such as mapping the tilapia value chain in Ghana10 or the shrimp value chain in Vietnam.11 Finally, specific farms or communities could be analysed to improve performance and utility. 9.2  Value chain analysis method Kaplinsky and Morris4 emphasise that no “correct” form exists to perform a value chain analysis but rather an adopted approach based fundamentally on the question to be answered. However, some aspects of the value chain analysis (mapping, margin distribution, updates or improvements, and governance) are especially notable in the analysis of aquatic products. At its most basic level, a value chain analysis systematically maps the economic agents or actors that participate in the production, distribution, commercialisation, and sale of a product (or products) in particular. This mapping evaluates the characteristics of the economic agents, profit structures and costs, goods fluxes along the chain, and characteristics of usage and destination of the national and foreign sale volumes. Such details can be compiled from a combination of primary surveys, focal groups, participative rural assessments (PRA), informal interviews, and secondary data. The value chain analysis may play a key role in identifying the distribution of the benefits of the economic agents in the chain.12 In other words, analysing the margins and profits within the chain can determine who benefits from participating in the chain and what economic agents could benefit from greater support or organisation. This part is particularly important in the context of developing countries (especially rural aquaculture), given that the poorest are the most vulnerable in the

Aquaculture value chain analysis  135 globalisation process (for example, by imports of greater quantities of substitute products). This analysis can be complemented by determining the nature of the participation within the chain to understand the characteristics of the participants. The value chain analysis can be used to examine the role of updates within the chain. Updating may imply improvements in product quality and design that allow producers to obtain a greater value or by diversifying the product lines offered. The updating process includes assessing the actors’ feasibility within the chain, as well as data on the current limitations. Governance problems play a key role in defining how such updating occurs. Furthermore, the structure of the regulations, incoming barriers, commercial restrictions, and standards can shape and influence even more the surrounding in which updating can be carried out. The value chain analysis can highlight its governance role.13 Governance in a value chain refers to the structure of the coordination relationships and mechanisms that exist among the economic agents in the value chain. Governance is important from the perspective of the policies through identifying institutional arrangements that may be necessary to improve capabilities in the value chain, remediate distribution distortions, and value-​added increase in the sector. (For more detail on the governance concept, see Chapter 15.) Therefore, the methodology should start with understanding the nature of the final markets, which are increasingly the motor in many value chains, and deal with their problems. 9.2.1  Point of entrance for the value chain analysis

To select the point of entrance, the purpose of the analysis and the component to be assessed should be considered. In any case, a clear and precise starting point should be established. For this, the scope and objective of the analysis should be accounted for. Is the value chain analysis being developed for a company, a regional industry, or at a global scale? Answering this will help us determine the main stakeholders of the value chain and will be useful to better map and evaluate the margins of the industry. Furthermore, what is the reason for which the analysis is being developed? For example, supposing that producers want to assess the effect that a new fishery policy may have on aquaculture production. By clarifying the analysis objective, they know they must assess all the actors that intervene in the processes related to aquaculture and fishing. In the case of aquaculture productions that are not fed or based on primary production, it is not necessary to evaluate the map of the different feed supplies and the role they play within the productive chain. Nevertheless, for the species fed, as mentioned previously, an analysis may be needed from the food supply, where it comes from, how it was produced, the actors that have an influence on this production, their performance, etc. However, fishing and aquaculture are not the only industries related to fish oil and meal (see Chapter 8). Later in the value chain, the products interact both in transformation processes and at distribution and marketing. Thus, the impacts on sale, availability, transport, price, etc. are going to be important both for external fed and non-​fed-​based aquaculture systems.

136  Daniel Peñalosa Martinell Since different elements could affect the value chain, the best option is to start with the element that has the minor influence possible from other sectors. In this case, we may start with the catch. How will this new fishery policy affect catch? Who are the actors that will be affected by this change? It is important to remark that the creation of a value chain analysis might not be linear, meaning that while it is being developed, the analyst might need to go back and re-​evaluate the pertinence of the objectives or scales selected at the initial stages of the analysis. 9.2.2  Value chain cartography

Starting by remembering all the chain components and their relationships simply using our memory could be extremely complex. Thus, one of the handiest tools in the value chain analysis is the use of graphic or map representations that show all the different chain components, mainly three elements: actors or stakeholders, inputs and outputs, or products and value-​added flows to these components. These elements can be mapped separately and, subsequently, their relationships analysed or directly dealt with in the value chain mapping from the start.14 Different types of maps exist that can be used in these analyses; their forms and structures depend completely on the analyst and should respond to the analysis needs and the analyst’s creativity. What should be searched for is simplicity and a universal understanding of these maps in a way that their representation may help more than one analyst and discussion among the different stakeholders. If the value chain structure is completely unknown, the recommendation is to start by mapping the production chain by simply assessing the inputs and outputs of the farm and providing a follow-​up to the final product up to the point planned by the analysis. The product may be considered fresh and sold directly from the farm as the final production chain or may provide a follow-​up along its transformation up to its final consumption (Figure 9.1). A production or supply map can be as simple or complex as required by the analysis. If the objective is only to study the product flow, identifying the different processes involved in the production of such a product is sufficient. This supply map could be useful as the first draft of the aquaculture industry or product to be

Figure 9.1 A general example of an aquaculture production chain.

Aquaculture value chain analysis  137 evaluated. It may also help as a tool to make general analyses or assess possible impacts associated with a shock since any cut in the process chain can affect the product supply and what could be done to solve it. Although the general supply maps can be sufficiently useful, the power of this tool multiplies if it is supplemented with an analysis or mapping of the actors involved in this process, which is especially true when the analysis has been centred on any product, region, or particular objective (Figure 9.2). When actors are mapped, the main ones that participate in the value chain should be represented as well as their existing relationships, qualities, and influence. The actors may be persons, organisations, civil groups, enterprises, or any other entity that may influence the value chain. Once the actors are identified, they should be characterised by the function of their role in the value chain. They can be divided into: Primary actors: Primary actors are those that affect directly the generated product value (either for good or bad). Depending on the analysis, they can be individual producers, processors, freezers, and outlets (points of sale). Secondary actors: Secondary actors participate indirectly or seasonally in the value chain. Some examples of these include hired consultants to increase the value of productive processes, auditors, or labelling processes for the sale of product export. Key actors: Key actors are those links that have the capacity of deciding on the chain development, either because of their abilities, knowledge, or power. They

Figure 9.2 Example of a stakeholders’ map.

138  Daniel Peñalosa Martinell may be decision makers, either private or public, for example, government authorities that grant permits and concessions for the production or financial institutions that provide capital for the development of the evaluated process. Veto players: Veto players are actors without which the value chain process could not be performed. They can stop the value chain. All veto players are key actors, but not all key actors are veto players. A classic example of a veto player is given in export processes. The federal government of an importing country has the capacity to stop completely the incoming production (i.e., because it does not comply with the import standards), cutting the chain completely and immediately. When the actors and their roles are already identified in the value chain, the existing relationships among them should be observed. These relationships may be narrow and formal, informal, in one direction, in both directions, conflictual and damaged, interrupted, etc. No unique nomenclature exists to show the players and their relationships on a map for actors. The most important thing is to understand the map in the most visual and fastest way possible. Once the actors are named and in their place within the production and input chain, it may go in depth in the best way possible in some points and analyses of the value chain, such as: Product segments: The different spaces in the market where the product can be placed and sold, those that are already exploited and those still to be exploited, giving rise to new sale opportunities, increasing profit margins, or product exploitation. Governance and public policy: Understanding the different processes associated with value generation in the aquaculture industry allow for optimising the industry coordination, regulation, and control. Understanding the actors and their different roles in the production chain allows a better application of measurements and public policy development to reach the objectives established by the state. For example, wealth distribution should be improved, maximising production to reach food security objectives or increasing the number or quality of working positions. How do producers have access to the final markets? This question is particularly significant from the point of view of governance and social responsibility because it allows for providing fair prices to producers, eliminating the presence of voracious intermediaries. This does not mean that all intermediaries are unnecessary or should be eliminated, but getting the producer closer to the final markets maximises benefits, which is particularly interesting for rural producers that at times are in need of offering their products at a rock bottom price facing the nonexistence of any other point of sale. Relationships, links, and trust: A transparent value chain map allows trusting relationships among the parts involved, a crucial element at the time of establishing

Aquaculture value chain analysis  139 contracts, prices, and conditions that allow working in collaboration, taking advantage of the qualities of each one of the links in a way that the system develops in the best way possible. Costs and margins: From the public point of view, we have mentioned that knowing the costs and margins allows developing public policies to improve wealth distribution; however, the value chain map is not exclusive to the public sphere. In the private arena, knowing the product value chain where one works allow evaluating which the opportunity areas are to maximise the benefits of an enterprise and analyse vertically the operations or acquisitions of other enterprises to obtain economies of scale.ii To deal with these points, one can (and should) use different sources of information, such as the following:

• Scientific and grey literature that deal with the different components of the value

chain (producers, markets, products, product origin, and destination,1 statistical and historical data, including production, and sale price in different value chain links). • Structured, semi-​structured, and non-​structured applied surveys to the main actors that make up the value chain. • Fieldwork is necessary with the objective of obtaining current data and establishing the main actors involved in the analysed fishery. Based on this objective, surveys and questionnaires should be developed to allow establishing who the main actors are and the relationship that exists among them, as well as costs, margins, and its distribution through the value chain. 9.3  Examples of value chain analysis applications in aquaculture As mentioned earlier, value chain analysis (VCA) can be used with several different objectives. In most cases, these objectives are not in conflict and can be a powerful tool to find areas of opportunity to improve the efficiencies of the value chain. For example, Macfadyen et al.15 developed a simple but robust value chain analysis for the pond aquaculture industry in Egypt. The analysis encompassed different objectives, including studying (1) the employment created by the industry; (2) a deeper understanding of the costs and earning profiles, as well as, the financial performance of the different sub-​sectors of the value chain; and (3) identifying the main constraints and issues affecting the different stakeholders. This work is a very good example of a financial-​focused value chain analysis, where the authors were able to dissect the value added and the flow of the product throughout the chain in different sectors and areas of the country, besides the proportional distribution of the margins gained by the different stakeholders. This information allowed coming up with drivers and indicators that allow for improved management and structure of the sector. Furthermore, they showed the impacts of this industry at a social scale together with the effect of pond aquaculture on employment and even indirectly on food security.

140  Daniel Peñalosa Martinell An example of how value chain analysis can impact the environmental production components is presented by Bush.20 He developed a Global Value Chain (GVC) analysis to study the effect of adopting eco-​certifications in both salmon and shrimp GVCs. Bush concluded that its sub-​sectors (such as shrimp and salmon) should be treated independently due to the different structures of their GVCs not only for eco-​labelling but also for optimal governance of the aquaculture industry. Value chain analysis is a wide tool with a very robust theoretical framework that allows organising and studying the flow of materials, marginal gains, and value added to an industry. This information is valuable for different stakeholders. In the case of aquaculture, one can observe the areas where more vulnerability exists either in terms of profitability or a concentration of market power from a small number of providers of goods or services that can significantly impact production. For example, VCA can help in the development of public policies by observing the areas where the margin is smaller and providing insights on where the public funds are better allocated, improving the distribution of the gains or supporting more marginalised communities.16 VCA is relatively new to aquaculture with some published works for some regions and species. Its application is still under research and development, but it carries significant promise regarding the implementation of efficient sustainable policies. 9.4  Value chain and globalisation For some citizens of the world in developing countries, globalisation contains the promise of potentially augmenting the rate and reach of industrial growth and the improvement of its manufacturing and service activities. People understand that without sustainable economic growth in their countries, little expectations exist to deal with poverty and inequality, which are so generalised. Thus, they see the growing integration of the global economy as an opportunity to enter a new era of economic and industrial growth reflected not only in the possibility of obtaining greater income but also in the improved availability of final products with better and more differentiated quality. However, at the same time, globalisation has had its dark side –​a growing tendency toward inequality within and between countries and a progressive incidence in absolute levels of poverty, not only in poor countries.17 These attributes, both positive and negative, of globalisation are generally exposed when great shocks in the social system occur, as observed in an economic depression, war, sanitary emergency, or any other type of disruptive element. The value chain analysis is centred on the interconnections of the productive sector, especially in the form in which enterprises and countries are integrated globally, an aspect that provides more details of the interactions between economies and processes than the traditional modes of economic and social analyses. The value chain analysis goes beyond a series of important weaknesses of the traditional sectorial analysis that tends to be static and suffers the weakness of its own limited parameters. The sectorial analysis fights to cope with the dynamic

Aquaculture value chain analysis  141 bonds between the productive activities that go beyond that sector, either of an intersectoral nature or between activities of the formal and informal sectors. On the other hand, the chain analysis flows by its interconnective and dynamic inclusion of the different elements that compose its relationships. The value chain also goes beyond the specific analysis of the enterprise in a great part of the literature on innovation. When these bonds are concentrated between links, they allow for discovering the dynamic flow of the economic, organisational, and coercive activities among producers within different sectors, including at a global scale. For example, shrimp and lobster produced in Southeast Asia, Latin America, and the Caribbean are indissolubly linked to global export commerce. Usually, the producers sell their product to an intermediary who pays the prices and freezes or transforms the product to subsequently export to food markets around the world.18 Furthermore, the notion of organisational interconnections that sustain the value chain analysis makes the interrelation between formal and informal work and the production for commercialising or self-​consumption easier to analyse. It also allows for identifying the processes instead of watching them as disconnected activity spheres. Finally, the value chain analysis is also useful as an analytical tool. It helps to understand the political environment that allows efficient resource allocation within the national economy despite its main use until now, and the way in which enterprises and countries participate in a global economy.19 The value chain analysis in aquaculture products has gained interest in the last few years. This result can be explained because analyses of this type allow identifying the processes that benefit in a greater measure in the value chain, allowing the application of public policies destined to maximise redistribution of the profits obtained from the activity.20 The idea of a value chain is associated with the concept of governance explored in depth in Chapter 15, which is of key importance for aquaculture because its value chains depend crucially on the use of natural and environmental resources. The value chain framework can also be used to understand the social links and traditional norms that can be used to conclude the participation of the different social strata in the activity and the potential impact of the value chain development in food security, activity management, and reducing poverty. 9.5  Final remarks As we have seen in this chapter, there is no single way of carrying out a value chain analysis. Although the framework of the analysis is general to the industry, the approach and results will be specific to the purpose for which it was created. As opposed to supply-​chain analysis, in which the aim of the analysis is to create efficient supply-​chain structures, value chain analysis is created to observe the value creation in financial terms and the distribution of the margins of said value. This information is crucial for decision-​makers. From a private industry perspective, this analysis allows observation of the areas where the company will

142  Daniel Peñalosa Martinell maximise its investments, what the company should do to maximise its benefits, and in which key areas it should invest to capture the most significant margins of the value chain. It also allows to minimise the influence of third parties or look for areas of opportunity to create value in its own product. From a public perspective, the value chain analysis is a powerful tool to identify the areas in which more vigilance and regulation are needed as well as to develop improved policies to streamline margin distribution, balancing the influence of all value chain stakeholders and reducing inequalities. 9.6  Chapter review questions 1 What are the differences and similarities between a supply chain analysis and a value chain analysis? 2 How can a value chain analysis be used to improve the sustainability of the aquaculture industry? 3 How would you define the point of entry for a value chain analysis? Recommended readings Ababouch, L., Nguyen, K. A. T., Castro de Souza, M., & Fernandez-​Polanco, J. (2023). Value chains and market access for aquaculture products. Journal of the World Aquaculture Society, 54(2), 527–​553. Bush, S. R., Belton, B., Little, D. C., & Islam, M. S. (2019). Emerging trends in aquaculture value chain research. Aquaculture, 498, 428–​434. Dubay, K., Tokuoka, S., & Gereffi, G. (2010). A Value Chain Analysis of the Sinaloa, Mexico Shrimp Fishery. Durham Duke University, Durham. Kaplinsky, R. & Morris, M. (2001). A Handbook for Value Chain Research, International Development Research Center, Ottawa, Canada. Little, D. C., Young, J. A., Zhang, W., Newton, R. W., Al Mamun, A., & Murray, F. J. (2018). Sustainable intensification of aquaculture value chains between Asia and Europe: A framework for understanding impacts and challenges. Aquaculture, 493, 338–​354. Loc, V. T. T., Bush, S. R., & Khiem, N. T. (2010). High and low value fish chains in the Mekong Delta: Challenges for livelihoods and governance. Environment, Development and Sustainability, 12(6), 889–​908. Nasr-​Allah, A. M. (2019). Value-​Chain Analysis-​An Assessment Approach to Estimate Lake Nasser Fisheries Performance. The International Lake Environment Committee Foundation. Porras, I., Mohammed, E. Y., Ali, L., Ali, M. S., & Hossain, M. B. (2017). Power, profits and payments for ecosystem services in Hilsa fisheries in Bangladesh: a value chain analysis. Marine Policy, 84, 60–​68.

Notes i The word utility in this context refers to the satisfaction generated by moving the products in the different chain links. Remember that utility not necessarily refers to the financial benefits deriving from the activity. For example, other non-​monetary or intangible elements may be included to a utility function depending on the analysis performed, which

Aquaculture value chain analysis  143 could bring happiness to the users, triumph sensation or any aspect that generate satisfaction to the actors of the chain. ii Economies of scale are a proportionate saving in costs gained by an increased level of production.

References 1 Taglioni, D., & Winkler, D. (2016). Making global value chains work for development. Trade and Development, Washington, DC: World Bank. http://​hdl.han​dle.net/​10986/​ 24426 License: CC BY 3.0 IGO. 2 Jordaan, H., Grové, B., & Backeberg, G. R. (2014). Conceptual framework for value chain analysis for poverty alleviation among smallholder farmers. Agrekon, 53(1), 1–​25. 3 Kruijssen, F., McDougall, C. L., & Van Asseldonk, I. J. (2018). Gender and aquaculture value chains: A review of key issues and implications for research. Aquaculture, 493, 328–​337. 4 Rosales, R. M., Pomeroy, R., Calabio, I. J., Batong, M., Cedo, K., Escara, N., ... & Sobrevega, M. A. (2017). Value chain analysis and small-​scale fisheries management. Marine Policy, 83, 11–​21. 5 Bjorndal, T., Child, A., & Lem, A. (2014). Value chain dynamics and the small-​scale sector: policy recommendations for small-​scale fisheries and aquaculture trade. FAO Fisheries and Aquaculture Technical Paper, (581), I. 6 Van Duijn, A. P., Beukers, R., & Van der Pijl, W. (2012). The Indonesian seafood sector; a value chain analysis. CBI & LEI, part of Wageningen UR. 7 Hernandez, R., Belton, B., Reardon, T., Hu, C., Zhang, X., & Ahmed, A. (2018). The “quiet revolution” in the aquaculture value chain in Bangladesh. Aquaculture, 493, 456–​468. 8 Knútsson, Ö., Klemensson, Ó., & Gestsson, H. (2008). Structural changes in the Icelandic fisheries sector –​ a value chain analysis. In: Proceedings of the Fourteenth Biennial Conference of the International Institute of Fisheries Economics & Trade, July 22–​25, 2008, Nha Trang, Vietnam: Achieving a Sustainable Future: Managing Aquaculture, Fishing, Trade and Development. Compiled by Ann L. Shriver. International Institute of Fisheries Economics & Trade, Corvallis, Oregon, USA, 2008. 9 Lim, G. (2016). Value chain upgrading: Evidence from the Singaporean aquaculture industry. Marine Policy, 63, 191–​197. 10 Anane-​Taabeah, G., Quagrainie, K., & Amisah, S. (2016). Assessment of farmed tilapia value chain in Ghana. Aquaculture International, 24, 903–​919. 11 Yoshida, N. (2017). Local institutions and global value chains: Development and challenges of shrimp aquaculture export industry in Vietnam. Journal of Agribusiness in Developing and Emerging Economies, 7(3), 318–​338. 12 Guritno, A. D. (2018). Agriculture value chain as an alternative to increase better income’s distribution: The case of Indonesia. Agricultural Value Chain, 1, 59–​80. 13 Ponte, S., Kelling, I., Jespersen, K. S., & Kruijssen, F. (2014). The blue revolution in Asia: upgrading and governance in aquaculture value chains. World Development, 64, 52–​64. 14 Frederick, S. (2019). Global value chain mapping. Edited by Stefano Ponte, Gary Gereffi, and Gale Raj-​Reichert. In Handbook on global value chains, Edward Elgard publishing, Cheltenham UK and Massachusetts US, 29–​53.

144  Daniel Peñalosa Martinell 15 Macfadyen, G., Nasr-​Alla, A. M., Al-​Kenawy, D., Fathi, M., Hebicha, H., Diab, A. M., Hussein, S. M., Abou-​Zeid, R. M., and El-​Naggar, G. (2012). Value-​chain analysis—​ An assessment methodology to estimate Egyptian aquaculture sector performance. Aquaculture, 362, 18–​27. 16 Bjørndal, T., Child, A., Lem, A., & Dey, M. M. (2015). Value chain dynamics and the small-​scale sector: a summary of findings and policy recommendations for fisheries and aquaculture trade. Aquaculture Economics & Management, 19(1), 148–​173. 17 Stiglitz, J. (2019). People, power, and profits: Progressive capitalism for an age of discontent. Penguin, UK. 18 Kaplinsky, R. (2000). Globalisation and unequalisation: what can be learned from value chain analysis?. Journal of Development Studies, 37(2), 117–​146. 19 Kaplinsky, R., & Morris, M. (2008). Value chain analysis: a tool for enhancing export supply policies. International Journal of Technological Learning, Innovation and Development, 1(3), 283–​308. 20 Bush, S. R., Belton, B., Little, D. C., & Islam, M. S. (2019). Emerging trends in aquaculture value chain research. Aquaculture, 498, 428–​434.

10 Aquaculture bioeconomics A brief introduction Fernando Aranceta Garza

The concept of bioeconomy arises from the link between two scientific disciplines, biology and economics. Biology focuses on the study of living things and all associated processes, while economics is responsible for the study of how to efficiently manage and distribute resources. Both sciences deal with the prediction and explanation of observed phenomena. Aquaculture bioeconomy is based on the interaction of different disciplines and sciences, operating under a multidisciplinary approach that allows for comprehensive analysis. It is supported using mathematical models and based on the General Theory of Systems Sciences, which allows knowing, understanding, and interrelating all the aspects that influence aquaculture production management. Bioeconomic models help producers in the decision-​making process, enabling the optimal production levels of the designed systems be identified, and allowing the optimisation of management strategies. Furthermore, these models represent a good methodological approach that allows the interaction of various components of aquaculture systems to be studied, helping public sector decision-​makers to design better public policies. This chapter briefly introduces the reader to the world of bioeconomic analysis from the design of a conceptual model to the methods used to develop a bioeconomic analysis, finalising with an example of their use in oyster production in northern Mexico. 10.1 Introduction Aquaculture is the culture of organisms in aquatic environments. These environments may be composed of fresh, brackish, or marine water, which support various culture species (e.g., fish, molluscs, crustaceans, seaweed). Freshwater aquaculture uses land-​based facilities, such as ponds, pens, cages, and even rice paddies; brackish aquaculture is developed in ponds or lagoons over coastal areas; and marine aquaculture operates using cages or pens for marine fishes in the open sea or subtidal baskets for molluscs (e.g., pectinids and oysters), and/​or different types of substrates for mollusc spat and seaweeds to settle and grow, such as ropes and rafts.1 DOI: 10.4324/9781003174271-13

146  Fernando Aranceta Garza Aquaculture production systems are usually classified using three criteria: (1) type of culture structure, (2) amount of water exchange, and most frequently, (3) intensity of culture (for specific features, see Table 10.1). The intensity of the aquaculture production systems reflects the stocking density, described as extensive, semi-​intensive, and intensive. In each of these types of production systems intensity performance will vary in response to many factors (e.g., Baluyut1; Asche y Bjorndal2), as shown in Table 10.1. Another sub-​classification within the intensive production system is the hyper-​or super-​intensive production system. This system represents production factories enabled with a closed or recirculating aquaculture system (RAS), independent of the environment and consequently reaching the highest production volumes in reduced areas. Nevertheless, the trade-​off is a very high cost in technology and infrastructure, using high-​value species, e.g., shrimp and salmon, primarily in Europe, where the markets usually pay high prices for the product. The aquaculture activity serves many purposes highlighting food security and commercial trade. In developing countries, aquaculture provides a mechanism for the population to access low-​cost and highly nutritious protein food addressing household food security issues, for example, using a backyard pond system. Additionally, aquaculture can improve local livelihoods by providing employment and income.3,4 For industrial or commercial purposes, aquaculture aims to produce profits for companiesi in a local, regional, or global market.ii Buyers and aquaculture firms interact in the market, allowing buyers to trade with sellers. The behaviour of aquaculture companies depends on the market structure defined by the number of companies in the aquaculture market, the ease with which they can enter or leave the market, and the ability to differentiate their products from those of other companies. The main market structures are perfect competitioniii (many companies producing similar products, price takers, e.g., tilapia fillets), oligopolyiv (a small group of companies in a market with substantial barriers to entry, e.g., salmon aquaculture) or monopolyv (i.e., one company supplies goods with no close substitute, price giver, e.g., caviar). For aquaculture, the number of companies producing a particular product (e.g., oysters, salmon, crab, shrimp), the accessibility of companies to the specific market, and the types/​processing of product sold (e.g. fresh, frozen, smoked, alive) determines the dominant market structure. In any company, the production of certain goods will be constrained by its technology (or production process) and costs to transform inputs (or factors of production) into outputs (Table 10.2). In the case of aquaculture companies, the primary inputs are capital (facilities, areas, equipment), labour (workers), and materials, such as seed (e.g., fry or spats), food, and water quality. These inputs are transformed into outputs as harvested biomass in kilograms or tonnes (Table 10.2). Thus, the company’s production function is the relationship between the amount of input used and the maximum output that can be produced given the current company technology.5 Specifically, when biological inputs are used, the production function depends on specific features, such as the species’ biological intrinsic factors (e.g., physiology, growth rate, and survivorship of the individuals through

newgenrtpdf

Table 10.1 Aquaculture systems defined by intensity criteria and their characteristics Production yield

Production inputs

Management

1) Extensive aquaculture refers to a culture system with a modest number of fish, which depends on food items found in the culture system (in situ production) where low fish densities are kept with minimum control, cost, and profit

Low stocking densities and mixed culture; low yield (500 to 2000 t/​ha) Pond size from 1 to 5 ha

Management is minimum and survival is low

2) Semi-​intensive system: includes additional stimulation of food production through the fertilisation of ponds that are small enough to enable their natural productivity to be enhanced or directly feeding the culture

From 3 to 15/​m2 and mixed or monoculture. (from 3 to 6 t/​ha) Pond size: 1 ha

Water exchange: not essential Aeration: not needed Feed used: natural feed External fertilisation: sometimes Engineering: not needed Investment: lower Care: low Labour: low Generator and current: not needed Larvae/​fry/​adult source: wild Minimum income and production costs 1 crop/​year Water exchange: 5–​10%/​day Aeration: 2HP Feed used: natural and formulated feed External fertilisation: sometimes Engineering: essential Investment: low to high Care: needed Labour: medium Generator and current: needed Larvae/​fry/​adult source: wild/​hatchery Moderate income and production costs 2 crops/​year

Certain amount of management is needed

(Continued)

Aquaculture bioeconomics: a brief introduction  147

Aquaculture systems

newgenrtpdf

Aquaculture systems

Production yield

Production inputs

Management

3) Intensive system: corresponds to the progressive extension of human control over major physiological functions of the cultivated organisms (reproduction, feeding, gene pool, diseases). In those systems, the environment is used essentially as physical support. They can be established in large as well as small marine and freshwater bodies, although systems where the environment is highly controlled necessarily are restricted to small volumes

Higher production (from 15 to 25 ton/​ha/​year) yield and highest prices Pond size: 0.2 to 0.05 ha

Water exchange: 20–​100%/​day Aeration: 8–​12 HP to continuous Feed used: pellet food (highly nutritious feed) External fertilisation: No Engineering: essential and high quality Investment: high to very high Care: essential Labour: High or specialised Generator and current: needed Larvae/​fry/​adult source: hatchery Highest income and production costs Batch-​wise/​year

Management is the highest, although difficult management problems can arise caused by high fish stocking densities

References: Troadec9; Subasinghe et al.3.

148  Fernando Aranceta Garza

Table 10.1  (Continued)

newgenrtpdf

Table 10.2 Aquaculture firm inputs or production factors Definition

Investment

Includes the development of the initial concept, species and site selection, capital formation, design and construction of the farm, and business management of the operation Long-​lived inputs such as: land or/​and water area; buildings/​plants/​factories/​stores; hauls/​tanks/​pens; pumps, filters, and tubes; and machines or vehicles Human services, such as managers, skilled and unskilled workers Electricity is needed for pumps, filters, aeration, and heating/​cooling in the case of semi-​intense and intense culture systems Seed: initial number of individuals seeded Feeding: food delivered to the reared organisms in an established frequency Water: percentage of water exchange needed per cultivation area Energy: quantity of energy required for water pumping, aeration, and heating/​cooling tank environment Period of the rearing cycle until harvested; its units are dependent on the species-​intrinsic factors

Capital Labour Energy Materials

Time Other production factors Environment

Technological innovations Disease breaks

The environment can be composed of three subfactors: 1. Physical: When the fish farmer does not control the environment, abiotic factors affect reared species. e.g., temperature, rainfall, insolation, water quality, and quantity 2. Institutional: governmental policy (e.g., taxes or subsidies), political and economic stability 3. Social: Includes traditions, customs, and religious beliefs which affect fish consumption and social acceptability of aquaculture as an individual, group, or community activity Any new discovery that allows the firm to increase its yield and/​or produce at a lower cost Any pathogen affecting final biomass and yield

Aquaculture bioeconomics: a brief introduction  149

Production factors

150  Fernando Aranceta Garza time) under a specific cultivation technology (e.g., extensive vs. intensive cultivation systems). Thus, by establishing the production function, any aquaculture company could predict the expected level of output –​valuable biomass per harvest6 –​helping to make production or commercial decisions cost-​effectively. Other factors can change aquaculture production levels regarding output quantity (or valuable biomass) and costs (Table 10.2). Environmental changes associated with climate change or strong seasonal variations can affect individual growth rates and mortalities in open cultivation systems (i.e., extensive and semi-​intensive). They can also cause a decline in the individual immune system, triggering disease outbreaks and reducing the aquaculture company’s output. On the contrary, some factors can improve production levels, such as new production technologies (e.g. improving survivorship or growth and more nutritious –​less costly –​feeding) and government policies, such as subsidies or taxation (output regulation). The objective of any aquaculture firm is to maximise production profitsvi under a specific technology, production factors, and related costs. The maximum profit level in any production process can be achieved by maximising the difference between revenues and production costs. This level can be achieved by applying a marginal analysisvii, where the firm marginal revenuesviii equal marginal costs,ix or by maximising the net present production profit value.x In aquaculture production, time is a critical input related to biological (e.g., growth rate and mortality per unit of time) and economic (associated costs and valuable harvested biomass) performances during production. Any bias in harvesting before or after the optimal harvest time translates into economic losses for the company. For this reason, one of the key objectives in aquaculture production is to determine the optimal harvesting time for any cultivated species. This objective can be achieved using mathematical modelling involving economics and biological sciences (among others) to solve the complex problem of maximising economic performance involving biological production. 10.2  Aquaculture bioeconomics Aquaculture bioeconomics had its foundation during the development of species cultivation on an industrial scale. During the 1980s, the first challenges to be solved were biological and technical constraints to meet the high market demand for marine products. The profits obtained under these conditions were large enough to compensate for management limitations and low production scales. During the 1990s, technical improvements in the production process occurred, achieving increments in supply and lowering operating costs, proving that economic and management aspects were vital to aquaculture’s global sustainable development. The main tool of the bioeconomic analysis is the bioeconomic model, which must be represented by the interaction of its components or sub-​models (Figure 10.1), simulating the aquaculture production process. Usually, bioeconomic modelling begins by assembling the biological sub-​model. The latter is represented by the seeding of individuals per tank or pond under an initial stocking density that grows and perishes in time until harvest.

newgenrtpdf

Aquaculture bioeconomics: a brief introduction  151

Figure 10.1 Description of the components or sub-​models that make up a bioeconomic model in aquaculture.

152  Fernando Aranceta Garza The technological sub-​model comprises the culture system feeding consumption, energy requirements, water quality, and other technological innovations. The sales of the harvested biomass (output) and its production-​associated costs (USD/​ time) conform to the economic sub-​model determining the company total costs, revenues (the market sets the price), and present production profit value. For the operation performance analysis, bioeconomic indicators are employed as a reference value for managing decision-​making concerning production objectives under biological, technological, and environmental constraints. Bioeconomic modelling provides an analysis tool for the production and management process of aquaculture farms, allowing the simulation of different scenarios or action strategies, helping to solve issues such as: a Determination of optimal harvesting time; b Determination of optimal seeding/​stocking; c Assessing bioeconomic effects of size heterogeneity, feeding, density-​ dependent, selective breeding, environmental conditions/​seasonality, diets, and probiotics performance; d Comparative performance analysis of different culture systems performance; e Assessing the risks of diseases and climate change; f Assessing uncertainty and risks associated with reaching/​exceeding the limit reference points of aquaculture performance. g Determining the economic feasibility of a project, such as the optimal location for a species (Box 10.1) or the possibility of rearing new species in a specific location. Finally, deriving from all the above, aquaculture bioeconomics can be defined as a field that integrates, for a given production biotechnology, the dynamics of aquatic species production with the associated costs and biomass value to determine optimal harvesting time and net present value, considering local environmental uncertainties and associated risks. 10.2.1  Bioeconomic indicators in aquaculture production

Aquaculture indicators are variables that measure the state of an aquaculture system and can assume discrete values. An indicator is defined as a variable, a pointer, an index of a complex phenomenon. Its fluctuations reveal the variations in components of the ecosystem, the resource, or the sector. When consider[sic] together, the position and trend of the indicator in relation to the criteria indicate the present state and dynamics of the system.6 In this manner, an aquaculture indicator is a variable derived from monitoring an aquaculture system, whose values show essential information about the state of aquaculture production believed to be relevant in achieving higher production efficiency (e.g., lowering costs/​obtaining higher profits). Reference points are discrete

Aquaculture bioeconomics: a brief introduction  153 values of aquaculture indicators, representing special cases that need management action to ensure the sustainability of the production process. Usually, there are two types of reference points: the limited reference points (LRPs) represent discrete values of critical biological, ecological, and economic indicators that the decision-​ maker, or aquaculture farmer, wishes to avoid reaching or exceeding. In contrast, target reference points (TRPs) are the desired or target discrete values where manager decision-​makers expect to locate the company’s production. The literature already presents a bioeconomic indicator framework applied in aquaculture systems composed of three subsystems (Table 10.3): (1) biological or living resource to be produced; (2) production technology; and (3) cost and revenues.7 For aquaculture rearing systems, and mostly in semi-​ intense and intense systems, identifying their biological, ecological, and economic indicators (sometimes including the environmental ones) is critical for monitoring their production process per cultured species. Each of TRP and LRP values for each indicator should be previously defined by managers (decision-​makers) with the aid of specialists in producing such aquatic species. 10.3  Bioeconomic model A bioeconomic model can be described using the general system theory, which establishes that a system or model comprises interrelated components or subsystems with pre-​determined boundaries, where inputs are transformed into outputs. The bioeconomic aquaculture model represents an abstraction of the production process in transforming inputs (seedlings, feeding, energy, etc.) into outputs (valuable biomass). A basic bioeconomic aquaculture model (Figure 10.1) comprises three sub-​models, as described below: biological, technological, and economical. Additionally, the bioeconomic model complexity can be increased by including others, e.g., an environmental sub-​model. 10.3.1  Biological sub-​model

The biological sub-​ model involves dynamic modelling of biological factors affecting the cultured species, meaning their change in time units. The time units can be established as day, week, month, and year depending on the inherent species characteristics and culture objectives. For example, the growth rate is species-​ specific and very variable. Molluscs, such as oysters, present a high growth rate and can reach harvestable biomass in 6 months, while some marine fishes present a lower growth rate and may reach harvestable biomass in several years. Moreover, some aquaculture companies may not need to reach an adult harvestable biomass, and they maximise profit by offering a particular product size, such as the case of the culturing of juvenile octopus for sale as “baby octopus” or red snapper plate size. The biological modelling process is usually based on the growth rate, measurement in weight, and survival of the individuals related to a specific density ( D0 )

newgenrtpdf

Aquaculture subsystems Biological subsystem

Indicators Larval and post-​larval production Juvenile and adult production Growth rate of juveniles and adults Biomass production

Technological subsystem

Reproduction laboratory Larval production laboratory Postlarvae and juvenile production facilities Adult production facilities Food production facility Harvesting technology Water quality

Economic subsystem

Operating costs of the reproduction laboratory Feeding and harvesting costs of juveniles and adults Price of species Harvest revenues Net revenues External costs of production

Survivors per larval stage (%/​larval period) Survivors at juvenile and adult stages (%/​juvenile period) The individual growth rate of juveniles The individual growth rate of adults Current over-​target production biomass (Bt/​B∞) Current over initial number of individuals in the grow-​out system (Nt/​N0) Days per year in operation Current over full production capacity ratio in the different facilities Days closed for disease control Annual harvest per hectare (ha) Biomass density of survivors at harvest time Nitrates and dissolved oxygen. Other critical water quality parameters (e.g. phosphates, ammonia, etc.) Variable costs over harvest value Feeding costs over total production costs Profits per cultivated unit of area Present value of profits (NPV) Internal rate of return (IRR) Negative externalities

154  Fernando Aranceta Garza

Table 10.3 Indicators for aquaculture production systems (from Seijo8)

Aquaculture bioeconomics: a brief introduction  155 until harvest in a specific period or culture period. Aquaculture modelling starts from an initial number of organisms seeded ( N 0 ) with a specific density, analysing their biological performance until harvest ( NT ) . Also, some models may include an environmental sub-​model relating biological performance with culture abiotic factors (e.g. temperature, salinity, pH, dissolved oxygen) to assess growth with seasonal fluctuations to optimise harvesting. 10.3.1.1 Growth

Growth refers to a change in weight/​length of an individual in time as a response to intrinsic (i.e. specific biological characteristics) and extrinsic factors (i.e. density of stocking, feeding rate, and quality, and environmental conditions of the culture).  dw  The instantaneous growth rate   establishes the weight change per unit  dt  of time for the total culture period until harvest. Integrating these observed values using a growth model results in a dynamic weight trajectory (Wt ) for the species. An important subsequent step is evaluating the growth model that best fits the trajectory for the biological aquaculture component –​ the von Bertalanffy growth model is the most commonly applied in aquaculture, where: dw = α w2 / 3 − β w dt

(10.1)

This equation represents the change in body weight given by the difference between the amount of anabolism represented as α w2 / 3 and the catabolism � βw , where α and β are constants. The solution of equation (10.1) for weight at time or age t (Wt )� is: Wt = A (1 − B ⋅ e −(k ⋅t ) ) ≈ Wt = W∞ (1 − e −(k ⋅t ) ) 3

3



(10.2, 10.3)

where A = α / β =​ mature weight; B� =​ integration constant; k = β / 3 =​rate of maturing, or curvature parameter; cubic exponential refers to isometric growth; and W∞ is the maximum weight reported of the species. Additionally, the von Bertalanffy growth formula can calculate the individuals’ length-​at-​age using the formula: Lt = L∞ (1 − e − k ⋅(t − t0 ) )



(10.4)

where L∞ is the maximum length of the species; k is the curvature parameter; and t0 is the adjustment parameter of the growth function.

156  Fernando Aranceta Garza From equations (10.3) and (10.4), age-​specific weight can be estimated by the following length–​weight relationship, where α and β are constants:

wt = α ⋅ Lt β

(10.5)

Besides the von Bertalanffy growth model, other growth models used to assess culture growth performance are: Gompertz

dw = α w − βw (lnw) dt

(10.6)

Chapman

dw = α wδ − β w 2 dt

(10.7)

Putter

dw = α wδ − β w γ dt

(10.8)

Logistic

dw = α w − β w2 dt

(10.9)

These model equations may show up to four free parameters for the model fitting process ( α, β, γ , δ ). As previously mentioned, the integration of any of the above equations (10.6–​10.9) results in the mathematical description of growth in weigh trajectory per unit of time: t

  dw Wt = W0 + ∫  = f ( w) dt � dt   0

(10.10)

The differential equation (10.10) cannot be solved by analytical methods. Instead, numerical methods approximate the solution of the differential equation, highlighting Euler as the most common mathematical method of numerical integration solving incrementally step by step per unit of time ( dt =​1), then:  dw  Wt = Wt −1 + h ⋅    dt 

(10.11)

Aquaculture bioeconomics: a brief introduction  157 dw is the observed growth dt rate from equations (10.6)–​(10.9) during period h . Equation (10.11) describes the dynamic weight trajectory of the bioeconomic aquaculture model. where Wt � is weight in time; h is culture period; and

10.3.1.2  Natural mortality

As mentioned earlier, each cultivation cycle starts with an initial number of individuals seeded ( N 0 ) with a specific density ( D0 ). The seeded individuals can be fingerlings (fish), spats (mollusc), or post-​larvae (crustaceans), which are reared and monitored until harvest. However, some individuals may die during the cultivation process because of natural mortality factors, such as low-​quality water, diseases, or cannibalism, during the total culture period. At the end of the period, the survivors will be harvested at a particular age, generating the company revenues. In this manner, natural mortality decreases during the rearing period, which is crucial for the economic solvency of the company. The calculation of the number of surviving individuals in time ( N t ) during a culture period is estimated using the exponential extinction model8: N t = N 0 * exp( − M *t )



(10.12)

where M represents a constant instantaneous mortality rate in the culture period. 10.3.1.3 Biomass

Biomass ( Bt ) refers to the average weight of each individual by a given area, which is the physical space of a rearing tank or marine cage. Biomass changes continuously in time because each individual gains biomass by incorporating food through their metabolism; its common trend or trajectory is a biomass increment at early ages until reaching a maximum peak. Then, biomass decreases steadily, caused by a decrement in growth rate and high natural mortality rates. Biomass-​at-​age or time ( Bt ) during a cultivation cycle can be calculated according to the equation: Bt = wt ⋅ N t � � � � �

(10.13)

where wt is average weight and N t � is the number of organisms in time t . 10.3.2  Technological sub-​model

The technological sub-​ model in a bioeconomic aquaculture model represents the culture system’s technological level and allows calculating numerically the

158  Fernando Aranceta Garza efficient quantity of feed and energy required to support growth per individual per aquaculture unit (e.g., a tank). One of the most important technological factors is the amount of feeding needed per individual, which is described further below. Additionally, in semi-​ intensive and intensive culture systems, other factors to consider are the energy requirements (Kw day–​1): (a) water pumping and recirculation are essential to avoid oxygen depletion, accumulation of metabolic wastes, such as ammonia, and concentrations of bacteria and other pathogenic microorganisms that could result in higher mortalities of the cultivated organisms; (b) aeration or oxygen added to the culture is vital to sustaining metabolism based on the amount of oxygen needed in a culture concerning the species density stocking and requirements; minimum dissolved oxygen concentration; and other gas concentrations, such as nitrogen, hydrogen, sulphide, and carbon dioxide; (c) water heating and cooling are essential for closed-​system cultures that avoid natural temperature fluctuations (e.g., seasonal fluctuations), achieving longer periods at the optimum growth temperature. The technological sub-​model allows calculating numerically the efficient quantity of feed and energy required (for water pumping, aeration, and heating/​cooling system) per individual size in weight. Other biotechnological advances to optimise the production process use the genetic engineering of individuals, where they can tolerate higher ranges of abiotic factors and/​or suppress their reproductive phase to allocate the individual energy and achieve higher growth performances. Other biotechnological advances use genetic engineering to optimise production, for example, higher growth rates in triploid organisms, less sensibility to abiotic factors or diseases, sex change, or reproductive disruption. 10.3.2.1  Feed consumption per individual

Aquaculture companies aim to grow organisms in the shortest possible time at the lowest possible cost. To achieve this, the farmer should provide the best possible feed to the cultured organisms to obtain a higher growth rate performance, reducing the time to harvest and trade. However, the feed represents one of the highest variable costs for the company. A key element in feed is the feed conversion ratio, which represents the amount consumed per individual to gain one unit of weight over time. Typically, FCR values range from 1 to >2.0. For example, cultured fish and shrimp using commercial feeds and intensive production methods can obtain an FCR ranging from 1.0 to 2.4. Lower FCR values, such as 1.0–​1.5, represent higher metabolic efficiency. FCR values from 1.6–​2.0 are acceptable but not as efficient, and values >2.0 represent a state of continuous or unrestrained feeding or ad libitum. However, the ad libitum level may result in production inefficiency due to the very high costs of feeding. Feeding over time ( Ft ) is calculated by multiplying the feed conversion ratio ( FCR ) by the expected change in weight of individuals in the following time interval:

Aquaculture bioeconomics: a brief introduction  159 Ft = N t * ( wt +1 − wt ) * FCR



(10.14)

where N t is the number of individuals in time � t ; ( wt +1 − wt ) is the expected change in weight for the following interval t� and when multiplied by N t � results in biomass in time ( Bt ) . Feeding costs depend directly on FCR efficiency, meaning any innovation in nutritional quality or probiotics that reduces FCR will generate lower feeding costs and higher overall profits. Additionally, FCR can be significantly influenced (metabolism and growth performance) by environmental factors, such as temperature, dissolved oxygen, and salinity, among others, especially when these values deviate from the species’ physiological optimum. The parameterisation of FCR can be calculated as: FCR =

FCt ( wT − w0 )

(10.15)

where FCt � is the total amount of food consumed in units of weight (e.g. g or kg) in relation to the difference between the initial ( w0 ) and final weight ( wT ) during the cultivation period T . In the case of bivalve aquaculture, most of the feeding comes from the ecosystem productivity where the farm is located, thus, feed costs are negligible. However, the trade-​off is that these bivalve farms are exposed to predators and parasites, harmful algal blooms, eutrophication associated with low oxygen periods, and more intense water temperatures, which certainly affect the commercialisation and survival of the cultured organisms. 10.3.3  Economic sub-​model

The economic sub-​model comprises estimating the farm total costs (i.e., variable and fixed costs) and revenues over a cultivation period or cycle, whose subtraction results in the company profits or utilities that, when applied a rate of discount, will generate the present value in time. 10.3.3.1  Costs and revenues

Costs are estimated considering the duration of the period analysed by applying either a short-​or long-​term analysis. The main differences between these analyses are that costs in the short term separate the variable and fixed costs of the company. In the long-​term analysis, all costs are variable. On average, most aquaculture production firms use short-​term cost analysis due to the dependence of the production process on growth and mortality per unit of time. Total costs are the sum of fixed and variable costs. Fixed costs are expenditures that do not change regardless of the output production or biomass level, e.g., lease

160  Fernando Aranceta Garza of an area or office, aquaculture permit, administration costs, and depreciation of the aquaculture infrastructure and equipment. Alternatively, the variable costs change with the level of biomass or output production, of which the feeding costs are highlighted as the most important. Other variable costs are associated with the daily operation of the aquaculture firm, e.g., wages for labour, maintenance costs, and energy expenses for aeration, filtration, and water pumping systems. Moreover, other costs are incurred only once on the culture, e.g., seedling and harvesting costs; the latter may include the unit cost of harvest management, marketing and sales, and other miscellaneous costs. The aquaculture company cost function C ( wt )� considers the daily operative costs of the production system, which includes the sum of fixed and variable costs obtained with the weight ( w ) gained per unit of time, calculated as: C ( wt ) = ( cf ⋅ Ft ) + OVCt + FCt + ( hc ⋅ N t )



(10.16)

where ( cf ⋅ Ft ) is the unit cost of feeding per total feeding over time (see eq. 10.14) of cultured individuals; (OVCt ) is the other variable cost in time ( t ), such as labour, the energy of water pumping, aeration, and water heating/​cooling system, and maintenance costs; ( FCt )� is the fixed costs; and ( hc ⋅ N t )� is the harvesting cost per individual. Revenues represent the product of the harvested valuable biomass (in kilograms or tonnes) multiplied by market price per kilogram or tonne. If the price varies within the individual biomass-​at-​age, it can be calculated as follows: Pt = Pmax (1 − exp( − rp*wt ) )



(10.17)

where Pmax is the maximum price obtained by the species; rp is the parameter that indicates the velocity at which price increases in relation to individual weight ( wt ) of species over time/​age. 10.3.3.2  Profits and present value

Profits or utilities ( π t ) are the difference between total revenues and cost function per unit of time ( t ): T

π t = N t ⋅ Pt ⋅ wt − ∑C ( wt )

(10.18)

t =0

where the revenues are the product of the survivors ( N t ) times their weight ( wt ) times the price ( Pt ).

Aquaculture bioeconomics: a brief introduction  161 The aquaculture analysis is dynamic (meaning it changes over time) because of the species’ individual growth and natural mortality (i.e., species’ intrinsic characteristics), which includes the accumulative costs until harvest time. Thus, the present value allows analysing of the flow of discounted profits using an annual t discount rate (1+ r ) . The present value of profit per year ( PV π t ) is calculated as follows: PV π t =

πt

(1 + r )t

(10.19)

�

Once the bioeconomic aquaculture model is built, the modellers can calculate the optimal harvesting period of the resource based on obtaining the time ( t ) where the net present value ( PV π t ) is maximum. This PV π t maximum can be calculated numerically in a datasheet or analytically with the following formula: t

PV π t = e − rt  p ( wt ) wt N t  − ∫e − rt C ( wt ) N t dt

(10.20)

0

where PV π t represents the maximum discounted profit in time t ; wt represents the size in weight in time t , r is the discount rate; and p ( w (t )) is the sale price. Another alternative for estimating the optimal time to harvest is applying a marginal analysis, referring to the economic cost or gain of producing an additional unit. According to microeconomic theory, the point that maximises a firm utility is where marginal cost equals marginal revenue over time (MR =​ MC). This point indicates the optimal time to harvest and corresponds to the optimal time derived from equation (10.21). For further information on the subject, we recommend reviewing the subject in specialised books on microeconomics (some book examples are included in the references). In a competitive market structure, marginal revenue is equal to the market price in equilibrium. The marginal cost and marginal revenues can be calculated as follows: MR =

changein total revenue ( Rt +1 − Rt ) = changein time (t + 1 − t )

(10.21)

MC =

change in total cost (TCt +1 − TCt ) = change in time (t + 1 − t )

(10.22)

162  Fernando Aranceta Garza 10.4  Final remarks Aquaculture represents a productive activity that involves the cultivation of aquatic organisms. The performance of an aquaculture firm under a semi-​intensive production system will depend on production factors such as investment, capital, labour, materials, environmental conditions, and time. At the same time, the firm’s production will be restricted by the level of technology, characteristics of the cultivable species, and production costs over time. The above is carried out to achieve the objective pursued by aquaculture companies, i.e., to maximise profits under a particular set of production factors. Bioeconomic modelling provides a framework for developing microeconomic analysis of the production factors, leading to recommendations to improve aquaculture production systems. It will also allow the analytical solving of fundamental questions in aquaculture production related to which species to cultivate, the optimal culture system, the optimal seeding and harvesting time, optimal harvesting size, profit maximisation level, and optimal crop density, and also can estimate the level of risk under different production strategies. 10.5  Chapter review questions 1 What is a bioeconomic model and what is its purpose? 2 What is understood as optimal harvest in bioeconomics and how do you estimate it? 3 Can you think of two bioeconomic indicators and what are they used for? Recommended readings Allen, P, Botsford, L, Schuur, A, Johnston, W (1984). Bioeconomics of Aquaculture, Developments in Aquaculture and Fisheries Science. Elsevier, New York. Asche, F., Pincinato, R. B. M., & Tveteras, R. (2022). Productivity in Global Aquaculture. In Handbook of Production Economics. Singapore: Springer Nature Singapore, pp. 1525–​1561. Cacho, O. J. (1997). Systems modelling and bioeconomic modelling in aquaculture. Aquaculture Economics & Management, 1(1-​2), 45–​64. Dorantes-​de-​la-​O, J. C. R., Maeda-​Martínez, A. N., Espinosa-​Chaurand, L. D., & Garza-​ Torres, R. (2023). Bioeconomic Modelling in Tilapia Aquaculture: A review. Reviews in Aquaculture. Kazmierczak Jr, R. F., & Caffey, R. H. (1996). The Bioeconomics of Recirculating Aquaculture Systems (No. 1083-​2016-​87310). Llorente, I., & Luna, L. (2016). Bioeconomic modelling in aquaculture: An overview of the literature. Aquaculture International, 24, 931–​948. Peñalosa Martinell, D., Vergara-​Solana, F. J., Almendarez-​Hernández, L. C., & Araneda-​ Padilla, M. E. (2020). Econometric models applied to aquaculture as tools for sustainable production. Reviews in Aquaculture, 12(3), 1344–​1359.

Aquaculture bioeconomics: a brief introduction  163 Box 10.1  Evaluating the impact of technology appropriation on economic profitability in aquaculture: the case study of the freshwater crayfish Cherax quadricarinatus (redclaw) Humberto Villarreal Colmenares President of the World Aquaculture Society Senior Researcher at CIBNOR, La Paz, BCS, Mexico Freshwater species dominate annual worldwide aquaculture production with over 55 million tons. Among freshwater crustaceans, the culture in China of the American crawfish, Procambarus clarkii, has resulted in a significant volume increase over the last 15 years with over 2 million tons produced in 2020, followed by the USA reaching 75,000 ton. Crayfish production in other countries is somewhat limited. The Australian Cherax crayfish is the next group in terms of production, with Australia (100 ton) and Malaysia (83 ton) numbering 3 and 4 on the list of producing countries. Production is extensive or semi-​intensive. In China, 48% of the area generates 62% of production using the Crayfish-​Rice Integrated System of Production (CRISP) developed in the 80s. The fishery–​rice system, with annular ditches around the rice field, generates 38% of production. Yields range from 1.5–​2.5 ton/​ha per year. However, there are significant constraints for resources (land and water) and some regions are having to limit farm growth. In the United States, 95% of production comes from Louisiana mainly using monoculture (rice and crayfish) or rotation (alternate crops) systems. Yields range from 0.7–​2.5 ton/​ha per year. In Australia, production of different Cherax sp. comes from WA, VIC, SA, and QLD using semi-​intensive clay ponds. Sizes vary from 40 to more than 100 g, and yields vary from 1.5–​3 ton/​ha/​yr. Commercial technologies used for crayfish production have not varied significantly since their inception in different countries. In China, adaptation of the species to traditional fish production systems allowed for a rapid increase in volume as the international markets in Europe and United States absorbed the initial output. From 2007, the dramatic increase in Chinese middle-​ class consumption of crayfish supported the rapid production increase in the country, with a current unmet demand of around 300,000 ton/​year strengthening the price to as high as US$12/​kg for 40 g crayfish. In Australia, the semi-​intensive technologies used for the different species have also not varied importantly in 35 years. Thus, yields and total volumes have remained at the same level, with prices around AUD$25/​kg for 60–​100 g organisms. Available literature shows that there are more efficient technologies available for commercial production. In this case study we use published information from my R&D group at CIBNOR for Cherax quadricarintus to make an economic comparison of the impact of commercial implementation of these technologies on farm profitability. I was part of the first commercial trials with the species in southern Queensland in 1984–​85, based on production systems originally developed

164  Fernando Aranceta Garza for marron, Cherax tenuimanus, in Western Australia. One cycle per year from stocking density 5–​10 g juveniles resulted in yields of around 1.5 ton/​ ha. An opportunity to evaluate production in earthen ponds in Tamaulipas, Mexico, occurred in 1994–​1997, using ponds previously used for tilapia, with aeration and 5% water exchange. One cycle production yielded 2.5 ton/​ ha. In 1997–​1999, I managed the largest Redclaw farm in the world (50 ha) in Ecuador, where we implemented a set of innovations, including in-​farm juvenile production, a nursery phase, and mono-​sex grow out of preadults on photo heterotrophic gravel-​lined ponds with continuous aeration and 5% water exchange/​day, to attain a 60–​100-​gram commercial size and 10.5 ton/​ ha/​year in three grow-​out cycles. From 2003–​2015 I managed a commercial farm and an Innovation and Technology Park in La Paz, BCS, Mexico, where we optimised the photo heterotrophic technology in HPDE-​lined ponds without water exchange, no discharges, and water reutilisation for several production cycles. Initial trials showed that 3.5 ton/​ha/​cycle (10.5 ton/​yr) could be achieved without water exchange. Improvements to the management of the photo heterotrophic system allowed for yields for 2.5–​3 grow-​out cycles per year to reach 4.8 ton/​ha/​cycle or 12–​14.4 ton/​ha. More recently, from 2015 to 2021, we developed a genetic nucleus with a wide pool to enhance production. Results showed a 43% increase in juvenile production and a 14% improvement on growth rate compared to the parental group. A comparison between the earthen, gravel-​lined, and HPDE-​lined systems is presented. Cost and income data were generated for different three-​phase 20 ha modules. Production costs were updated to 2022. Fixed costs included maintenance, pond preparation, personnel, chemicals and additives, and harvest. Variable costs included the number of juveniles or preadults (25 g), feed, energy for water exchange, and energy for aeration. A consulting fee was included for years 1–​3 and a sale price of US$15.4/​kg was used for the analysis. The intensive photoheterotrophic zero-​water exchange technology is highly effective. With proper management of mono-​sex grows out, females grow at a good rate and reach commercial size (> 40 g). The reported difference in revenue with male ponds is less than 13%. This would prevent a common practice at some farms that discard or sell females at small sizes (30–​40 g), improving the efficiency of juveniles and reducing costs. Benefit/​cost increases 40% at the most efficient commercial photo heterotrophic technology evaluated, compared with traditional earthen pond production. However, the analysis shows that increasing CAPEX must result in an increase in sales to maintain the desired B/​ C, as shown when HPDE-​lined ponds yield 3.5 ton/​ha/​cycle. This technology is highly biosecure, environmentally friendly, sustainable, and economically attractive. Preliminary trials using the wide-​pool genetic nucleus stock show that B/​C is over 2. The knowledge-​based data supporting this technology provide certainty for investing in a commercial venture. With a growing demand for crayfish worldwide (18%/​yr), the redclaw crayfish (Cherax quadricarinatus) could become the next successfully mass-​produced crustacean.

newgenrtpdf

Earth Gravel HDPE3.5 HDPE4.8

CAPEX

Yield

Sales

Cost

Cost

Income

Income

IRR

NPV

($)

kg/​yr

($)

Yr 1-​3

Yr 4-​10

Yr 1-​3

Yr 4-​10

(%)

($)

3,094,236 3,214,236 4,752,204 4,752,204

88,133 123,386 123,386 169,214

1,321,125 1,849,574 1,849,574 2,536,559

742,930 833,150 833,150 950,498

692,930 783,150 783,150 900,498

578,194 1,016,424 1,016,424 1,586,061

628,194 1,066,424 1,066,424 1,636,061

14.54 29.91 17.60 31.63

299,205 2,402,865 1,029,679 3,903,408

B/​C

Cost $/​kg

1.30 1.70 1.45 1.82

7.9 6.4 6.4 5.3

Aquaculture bioeconomics: a brief introduction  165

System

166  Fernando Aranceta Garza Appendix Constructing an aquaculture bioeconomic model To represent the construction of a bioeconomic aquaculture model, we will use an example of a penaeid shrimp farm whose previously estimated parameters for each sub-​model are in Table 10.4 (taken from Seijo 2004). These parameters must be estimated each time a culture cycle is modelled under new species and technological conditions. The farm is a semi-​intensive system where balanced feed is added to the juveniles until they reach harvest size. The water in the ponds is renewed naturally with each tide cycle. One primary research question is: What would the optimal harvest time be for the shrimp farm? To answer the question, we will develop an evaluation using a deterministic and dynamic bioeconomic model for a farm with an effective culture area of 100 ha, seeding 75 million individuals ( N t =0 ) , giving a density of 75 individuals/​m2. To avoid complicating the exercise, we will assume that the environment is stable and the growth rate of the seeded batch is homogeneous. The mathematical development of the previous section equations using the Table 10.4 parameters for each sub-​model that comprises the bioeconomic aquaculture model was elaborated using Microsoft Excel. The results are shown below. A.1  Constructing the biological sub-​model With the data obtained from Table 10.4, we can start constructing the biological sub-​model. For this exercise, we are assuming that the best model that explained shrimp growth was the von Bertalanffy growth model. We are calculating a cultivation period (t) of 24 months ( tmax =� 24) for demonstration purposes, but usually, the duration of a shrimp culture could vary from 4 to 8 months. Thus, we start calculating growth, survival, and biomass: For growth, we use equations (10.4) and (10.5). The number of individuals surviving the aquaculture production system is calculated by equation (10.12). Equation

Equation with values from Table 10.4

( 4) Lt = L∞ (1 − e − k ⋅(t − t ) ) (5)� wt = α ⋅ Lt β (12) Nt = N 0 * exp(− M *t ) 0

Lt = 23(1 − e −0.26⋅(t − 0) ) wt = 0.0037 * Lt 3 N t = 75, 000, 000 * exp (−0.11*t )

t� =​time interval in months, from 1 to 25. Lt � =​length at the month t . The dynamic biomass of the production system per month ( t ) in tonnes is estimated with equation (10.13): Bt =

wt ⋅ N t 1, 000, 000 g

newgenrtpdf

Table 10.4 Bioeconomic parameters for a shrimp production semi-​intensive system divided in biological, technological, and economical sub-​model Biological sub-​model Symbol

Value

Units

Post-​larvae introduced in the production system in t = 0 Age-​specific natural mortality Curvature parameter of growth equation Adjustment parameter Maximum length of species Parameter of length weight function Parameter of isometric growth

N0 M k t0 L∞ α β

75,000,000 0.11 0.26 0 23 0.0037 3

individuals month–​1 month–​1 month–​1 cm kg/​cm –​

Technological sub-​model Parameters Food conversion rate

Symbol

Value 1.7

Units ratio

Symbol

Value 0.6 0.0025 0.0015 55000 5000 21.6 0.053 0.008

Units USD/​kg USD/​ind USD/​ind USD/​month USD/​month US/​kg USD/​g month–​1

Symbol

Value 0.1

Units month–​1

Economic sub-​model Parameters Unit cost of food Unit cost of harvest Unit cost of removing head Other variable costs Fixed cost Price of species Curvature parameter of price function Rate of discount Environmental sub-​model Parameter Risk factor e.g. disease

FCR

cf hc hoc OVC (labor, energy and maintenance costs) FC Pmax rp d

rf

Note: We can deal with other aquaculture production complexities, such as: continuous production systems (i.e. seasonality (Tian et al. 1993; Cacho et al. 1990), alternative aeration and water circulation systems (Martinez & Seijo 2001; Huguenun and Colt 2002; Peñalosa Martinell et al. 2021) or varying production intensities (Villanueva et al., 2013). Appropriate dynamic bioeconomic models should be used to represent such relevant factors of the farm production process. For long-​run investment analysis see Hanson et al. (1985), Hatch & Kinnucan (1993) and Martínez et al. (1994).

Aquaculture bioeconomics: a brief introduction  167

Parameters

168  Fernando Aranceta Garza A.1.1  Results of the biological sub-​model

Figure 10.2 shows the results of dynamic growth, natural mortality, and biomass. The classic cohort survival trajectory can be observed shaped as a negative exponential due to applying constant natural mortality ( M ). Figure 10.2 (top) shows that at the initial phase or t� =​0, the culture cycle began with 75 million post-​larvae, where at the following months ( t > 0 ), the individuals were subjected to a constant 10.4% of mortality for each month or unit of time, until t = 24 months, resulting in survival of 5.3 million individuals at the end of the period. Dynamic growth in length and weight are shown in Figure 10.2 (middle). The weight trajectory curvature showed the highest growth rates at t =​4, followed by a decline and stabilisation of the growth rate to 0 as juveniles approach their maximum weight value. The product of the survivors with the weight at each month interval resulted in the dynamic biomass curve in Figure 10.2 (bottom). The biomass trajectory showed a maximum peak of 938 t in t =​ 8 under the assumed technology and species intrinsic characteristics. After the peak, biomass decreases due to the drop in growth rate and natural mortality of individuals. A.2  Constructing the technological sub-​model The technology sub-​model was based on the food conversion rate, and the feeding over time is calculated in tons from Equation (10.14) as follows: Ft =

N t * ( wt +1 − wt ) *FCR 1, 000, 000 g

A.2.1  Results of the technological model

The results for the technological model are shown in Figure 10.3, where the maximum food consumption was reached at t = 3 showing the relationship with the expected weight change ( ∆w ) and the total individual survival for that month ( N t ). The feed conversion rate (FCR) was 1.7 (an acceptable value but not so efficient in cost terms), which is the amount of feed needed to be consumed by individuals to gain a unit of weight or 1 gram of bodyweight. A.3  Economic sub-​model For determining the firm present value ( PV π t ) , first, the revenues and cost functions must be estimated to obtain the profits in time, represented by equations (10.16), (10.17), and (10.18).

Aquaculture bioeconomics: a brief introduction  169

Figure 10.2 (A, B, C) Biological performance of a shrimp production semi-​intensive system from top to bottom: individual survival in time; individual length and growth in time; and biomass in time.

170  Fernando Aranceta Garza

Figure 10.3 Technological performance in a shrimp production semi-​intensive system from top to bottom: feeding over time is the product of the feed conversion rate (FCR) and the expected change in weight (∆w); expected change in weight per individual in time.

C ( wt ) = ( cf ⋅ Ft ) + OVCt + FCt + ( hc ⋅ N t ) Pt = Pmax (1 − exp( − rp*wt ) ) T

π t = N t ⋅ Pt ⋅ wt − ∑C ( wt ) t =0

Aquaculture bioeconomics: a brief introduction  171

Figure 10.4 Total costs, total revenues, and profits in the shrimp production process.

Subsequently, the discounting of the profits by the rate of discount per month resulted in the present value per monthly interval as follows: PV π t =

πt

(1 + r )t

Once the monthly present values are estimated, the research question about establishing the optimal harvest time can be answered under the criterion of the maximum PV value (equation 10.20). Another complementary alternative addressed is applying the marginal analysis criterion (equations 10.22 and 10.23). A.3.1  Results of the economic model

The total cost and revenues per unit of time (month) are shown in Figure 10.4. The initial cultivation phase shows some economic losses in production, which have derived from the fixed costs and post-​larva purchase (seedlings) with no revenue generation. As these post-​larva grow in time, their potential economic value in revenue increases concerning individual weight gain and survivorship. The dynamic profits peaked in month 9 and decreased until reaching negative values in month 22. This negative trend is caused by a decrease in shrimp biomass (revenues) concerning lower growth, constant mortalities, and relatively higher cost over time. Figure 10.5 shows the optimal harvest timing was nine months with a total production of 926 t/​100 ha of biomass of age nine individuals, representing a maximum PV of ~US$ 132,000/​ha. This result was also supported under the marginal analysis (Figure 10.5), showing the maximal-​present value under the condition MC� = MR .

172  Fernando Aranceta Garza

Figure 10.5 Determination of the optimal time of harvest using the complementary methods of marginal analyses and the maximum present value of profits (PVπ). Arrow denotes that when MC =​MR =​(PVπ).

As another possible extension of this exercise, incorporate a disease risk factor ( rf ) in the equation (10.20) as: PV π t =

πt

(1 + r + rf )t

Now repeat the exercise and estimate the optimum harvest time under a disease risk, compare your results with the first exercise, and try to explain the new harvesting decision as a shrimp production manager. A.4  Applied examples using the aquaculture bioeconomic model The following are literature references that use the bioeconomic aquaculture-​based model developed in this chapter with other scopes, species, and scientific questions. References 1. Martínez, J. A., & Seijo, J. C. (2001). Alternative cycling strategies for shrimp farming in arid zones of Mexico: Dealing with risk and uncertainty. Marine Resource Economics, 16(1), 51–​63. 2. Martínez, J. A., & Seijo, J. C. (2001). Economics of risk and uncertainty of alternative water exchange and aeration rates in semi-​intensive shrimp culture systems. Aquaculture Economics & Management, 5(3-​4), 129–​145.

Aquaculture bioeconomics: a brief introduction  173 3. Seijo, J. C. (2004). Risk of exceeding bioeconomic limit reference points in shrimp aquaculture systems. Aquaculture Economics & Management, 8(3-​4), 201–​212. 4. Duarte, J. A., Villanueva, R., Seijo, J. C., & Vela, M. A. (2022). Ocean acidification effects on aquaculture of a high resilient calcifier species: A bioeconomic approach. Aquaculture, 559, 738426. 5. Kim, P. B., Klanian, M. G., & Seijo, J. C. (2020). Effect of size heterogeneity of Nile tilapia (Oreochromis niloticus) on the optimal harvest time: a bioeconomics approach. Latin Merican Journal of Aquatic Research, 48(1), 65–​73. 6. Villanueva, R. R., Araneda, M. E., Vela, M., & Seijo, J. C. (2013). Selecting stocking density in different climatic seasons: A decision theory approach to intensive aquaculture. Aquaculture, 384, 25–​34. 7. Araneda, M. E., Hernández, J. M., Gasca-​Leyva, E., & Vela, M. A. (2013). Growth modelling including size heterogeneity: Application to the intensive culture of white shrimp (P. vannamei) in freshwater. Aquacultural Engineering, 56, 1–​12. 8. Seijo, J. C., Villanueva-​Poot, R., & Charles, A. (2016). Bioeconomics of ocean acidification effects on fisheries targeting calcifier species: A decision theory approach. Fisheries Research, 176, 1–​14. 9. Araneda, M., Hernández, J., Domínguez-​May, R., Vela, M. A., & Gasca-​Leyva, E. (2018). Harvest time optimization considering the stocking density and heterogeneity of sizes in the culture of white shrimp in freshwater. Aquaculture Economics & Management, 22(4), 431–​457. 10. Vela, M. A., Villarreal, H., Araneda, M., & Espinosa-​Faller, F. J. (2019). Growth and survival of juvenile red drum, Sciaenops ocellatus, acclimated to freshwater at three different stocking densities in a partial recirculation system. Journal of the World Aquaculture Society, 50(1), 87–​103. 11. Peñalosa-​Martinell, D., Araneda-​Padilla, M., Dumas, S., Martinez-​Díaz, S., & Vela-​ Magaña, M. (2021). The use of probiotics in larval whiteleg shrimp (Litopenaeus vannamei) production: A marginal analysis of bioeconomic feasibility. Aquaculture Research, 52(3), 943–​951. 12. Musa, B. O., Hernández-​Flores, A., Adeogun, O. A., Duarte, J. A., & Villanueva-​Poot, R. (2022). Stochastic bioeconomic analysis of intensive African Catfish cultivation with three sources of uncertainty. Aquaculture International, 30(6), 2919–​2935.

Notes i

Firm: an organisation or enterprise that combines inputs of labour, capital, land, and raw or finished component materials to produce outputs; in aquaculture the output is tonnes of biomass. ii Global market: interaction between potential buyers and sellers across national borders occurring in a combination of demand and supply. iii Perfecto competition: a market structure composed of many business competitors that sell identical products. iv Oligopoly: a market structure composed of few large firms that have all or most of the sales in an industry. v Monopoly: a market structure composed of one firm producing all the output in a market. vi Profits: total revenues —​total cost.

174  Fernando Aranceta Garza vii Marginal analysis: examination of decisions at the margin, meaning a little more or a little less from the status quo. viii Marginal revenues: the additional revenue gained from selling one more unit. ix Marginal costs: the additional cost of producing one unit. x Marginal costs: the additional cost of producing one unit.

References 1 2 3 4 5 6 7 8

9

Baluyut, E. A. (1989). Aquaculture systems and practices: a selected review. United Nations Development Programme and Food and Agriculture Organization of the United Nations, Rome. FAO ADCP Report 89/​43 Asche, F., & Bjorndal, T. (2011). The economics of salmon aquaculture. John Wiley & Sons, Oxford, UK. Subasinghe, R., Soto, D., & Jia, J. (2009). Global aquaculture and its role in sustainable development. Reviews in Aquaculture, 1(1), 2–​9. doi:10.1111/​j.1753-​5131.2008.01002. Karim, M., Leemans, K., Akester, M., & Phillips, M. (2020). Performance of emergent aquaculture technologies in Myanmar; challenges and opportunities. Aquaculture, 519, 734875. Anderson, L. (2004). The Economics of Fisheries Management. The Blackburn Press, USA. García, S. M. (1996) Indicators for sustainable development in fisheries. Paper presented at the 2nd World Fisheries Congress. Workshop on Fisheries Sustainability Indicators. Brisbane, Australia, August 1996. Seijo, J. C. (2004). Risk of exceeding bioeconomic limit reference points in shrimp aquaculture systems. Aquaculture Economics & Management, 8(3–​4), 201–​212. Beverton, R. J. H. and S. J. Holt (1959). A review of the lifespans and mortality rates of fish in nature, and their relation to growth and other physiological characteristics. p. 142–​180. In G.E.W. Wolstenholme and M. O’Connor (eds.) CIBA Foundation Colloquia on Ageing: The Lifespan of Animals. Vol. 5. J & A Churchill Ltd, London. Troadec, J. P. (1991). Extensive aquaculture: a future opportunity for increasing fish production and a new field for fishery investigations. In ICES Marine Science Symposia (Vol. 192, pp. 2–​5).

11 Aquaculture Uncertainty sources and risk quantification techniques Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell Decision-​making in aquaculture is regularly made under the assumption of certainty, especially through their own experiences or those of other producers, even when producers are aware of the probable occurrence of undesirable events. This situation has caused some of the productive proposals to fail because the stochasticity variable has not been considered, only deterministic scenarios. Furthermore, this perception of risk and how it is managed has pushed away several financial stakeholders, since they don’t understand the industry and are not willing to assume unknown risks. This situation reduces the capacity of the industry as a whole to invest in new technologies and keep growing. As a result, investment in sustainable technologies is reduced and business as usual is maintained, creating a negative cycle. One of the alternatives to improve this condition has been the application of risk and uncertainty analysis. This approach –​through decision theory and business analytics –​allows estimating and evaluating the consequences of exposure to a hazard or a source of uncertainty. Thus, the purpose of this analysis is to be able to quantify “uncertainty” and then use it in the calculation of probabilities to achieve the desired objective and/​or not incur undesirable events. Therefore, this chapter reviews and discusses the importance of risk and uncertainty in decision-​making in aquaculture production, presenting the main sources of uncertainty in aquaculture activities. Additionally, the different methods for estimating risk and uncertainty in aquaculture are explored and recent studies where these methods are applied are also presented. Finally, the benefits of incorporating these types of studies into aquaculture activities are discussed, in addition to reviewing recent studies where risk management has begun to be strengthened through the application of machine learning and artificial intelligence techniques. The chapter ends with a basic proposal for risk and uncertainty quantification. 11.1 Introduction As mentioned at the beginning of this book, aquaculture is the fastest-​growing food production centre in the world. This activity –​through different production DOI: 10.4324/9781003174271-14

176  Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell methods –​has contributed not only to greater economic development and employment generation but also to food security in many developing countries. Despite this remarkable growth and aquaculture potential, production could still be greater since it has been carried out with an incomplete knowledge of variables and productive factors that if known and managed could further increase the productive yield of the species in culture under the technological conditions in which they are produced.1 In this sense, aquaculture production yields are affected by changes in the environment, intrinsic biological factors of the species, and surrounding economies. These changes affect production decisions and many of them are characterised by being unexpected. In the salmon hatchery, for example, unexpected events, such as microalgal blooms, have led to production shutdowns. In shrimp farming, the movement of larvae, juveniles, and broodstock between different locations or countries has generated the introduction and spread of a series of diseases, causing a negative scenario for production that was neither foreseen nor sufficiently regulated at the beginning. At the economic level, unforeseen changes in prices, and decreased supply and demand for inputs have also caused inadequate planning and negative profits at the financial level in many hatcheries. A better understanding of the sources of these changes could help in being better prepared to cope with these hitherto stochastic processes. Although aquaculture producers are aware of the likely undesirable events, they often do not have quantitative tools to assess potential risks given the large number of variables and sources of uncertainty. Thus, they continue making decisions trying to incorporate as best as possible their previous experience or that of other producers. This situation has caused several of the current productive proposals to have a high possibility of failure or not reaching their full potential because they have not considered the likely future scenarios. Likewise, many other proposals –​in the middle of the project study process –​are evaluated in a deterministic manner, i.e., all the inputs that influence the activity (biological, technological, and economic) are considered to be stable without any variation. The use of quantitative tools that increase the probability of making better decisions is an important objective in optimising production processes by incorporating the main sources of change in the production performance variables. A fundamental piece to meet such objectives has been the implementation of techniques to quantify risk in aquaculture. These methods are part of the operation research branch2 and in recent years grouped in the business analytics approach.3 These techniques have been essential for evaluating productive and economic processes applied to renewable natural resources, such as fisheries and forestry. Much of the decision-​making associated with the management of these resources, such as harvest rate and optimal harvest, depends on a wide range of sources of uncertainty. In aquaculture, these tools have been used to estimate the risks that this sector generates for society and the environment. However, in recent years they have been used to assess the risks that affect the success and sustainability of the industry. In particular, financial risk assessment and its application to optimal technical-​economic management aims to measure the risks associated with uncertainty in production decisions.

Aquaculture: uncertainty sources and risk quantification methods  177 Therefore, the objective of this chapter is to show the importance of a risk and uncertainty analysis on production decisions in aquaculture, how to evaluate them, and what the possible scopes of their application are. To this end, (a) concepts of risk and uncertainty in aquaculture are defined; (b) sources of uncertainty that affect production decisions are classified; (c) different techniques to estimate risks are explored, discussing the scopes in aquaculture research where they have been applied; (d) beneficial effects of incorporating this type of studies are discussed; and (e) basic steps to be taken into account are identified to implement risk quantification in aquaculture activity. 11.2  Risk and uncertainty in aquaculture Uncertainty is understood as the “imperfect knowledge of the state or processes of nature” definition reached by the Technical Consultation on the Precautionary Approach to Capture Fisheries. According to Caddy and Mahon, “Risk should be understood as the probability that something will go wrong”.4 Both concepts are inherent to aquaculture processes where lack of certainty is a common condition with respect to future events since many of the processes occur under conditions of incomplete knowledge of the state of nature (e.g. exogenous, biological, ecological, and economic variables), over which the producer has no control. The probability of these events occurring and causing undesirable or unfavourable situations is, in general, what generates the risk, whether biological (suboptimal yield) or financial (low return on investment). Quantitatively estimating this level of risk is a challenge. Even when dealing with the same species, the sources of uncertainty and levels of risk can be diametrically opposed. For example, risks in Chile in salmon farming are substantially different from those in Norway due to various factors, such as the timing of disease occurrence, input costs, and harvesting times. Life cycles between species also have a different disposition to risk. Their effects can be simple or complex, depending on the stage of production. In salmon farms, the pre-​spawning stage in freshwater presents very different risks compared to growth in sea cages. Despite these difficulties, a large number of factors –​common among species and productions –​intervene in the processes. These factors are characterised by one of the following features: variable but predictable or openly random behaviour. Thus, an initial phase of risk and uncertainty analysis consists of identifying the main sources of uncertainty and then determining their predictability. 11.2.1  Uncertainty sources in aquaculture

Several authors have made important contributions to identifying sources of uncertainty in productive biological environments, mainly in fishery resources (see the “Recommended readings” section at the end of this chapter). Aquaculture also presents different sources of uncertainty. Their identification is an essential step not only to determine the probability of a negative uncertainty event occurring and make it somewhat predictable but also to evaluate the possible

178  Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell consequences that could be caused by the uncertainty variables if they were to occur. Although no detailed description of such “sources of uncertainty” exists in aquaculture literature, different reports have specified those that commonly occur, regardless of the species’ geographical location and type of culture. 11.2.2  Uncertainty in environmental variables

Part of aquaculture’s productive and economic success depends on the environmental conditions in which it develops, for example, temperature, luminosity, inorganic nutrient content, salinity, water column stability, and others that are still under investigation. In general, these conditions are characterised by high variations, which often have a significant effect on production (see Chapter 4). However, their magnitude depends on the type of production. Obviously, aquaculture systems in the sea and lakes are much more exposed to environmental components and oceanographic phenomena than those developed inland with ponds and closed systems. Open aquaculture systems have a special relevance that may seem unexpected, such as microalgal upwelling and blooming. The occurrence of these phenomena depends on several environmental factors. In fish, their appearance has surprised many producers by the mass appearance of fish affected by sudden death, mainly in the early morning and for no apparent reason: healthy, well fed, with no infections or diseases in sight. In molluscs, these phenomena have caused the restriction of market sales, especially due to the high accumulation and concentration of biotoxins. Additionally, the low heterogeneity of growth, population, and survival are also due to the discontinuous levels of upwelling that induce a decrease in food availability. 11.2.3  Uncertainty in operational and technological variables

Uncertainties in operational and technological variables are those threats that appear due to a management action and have an impact on the species being farmed. Due to improvements in the production processes of most species, the competition among aquaculture producers is increasing. This situation has led them to increase culture densities, introduce exogenous species with better performance, and change traditional production methods. These measures at the commercial level are often not without dangers. The decisions make the presence of a number of harmful biological factors possible, such as pathogens and predators that incur diseases and parasites. In most cases, these disturbances cause death, injury, and stress to the organisms, as well as damage to production systems and structures. A large number of aquaculture companies have seen their profitability decrease due to accidents or disturbances in production, which often originate fortuitously, mainly due to failures in the mechanical equipment that controls water quality parameters. Unlike traditional systems, recirculating aquaculture systems (RAS) are much more prone to failures due to the series of devices that compose them. For example, problems in degassing equipment lead to increased carbon dioxide concentrations and decreased oxygen. The result of this situation is not only less

Aquaculture: uncertainty sources and risk quantification methods  179 oxygen but also reduced ability of organisms to use the available oxygen, causing harmful effects on the health of the population and their survival, resulting in large economic losses. 11.2.4  Uncertainty in biological behaviour

Unlike the category described above, cases exist where variability is not manifested by environmental changes that modify expression but by purely biological variation. Generally, production growth models are deterministic and the organisms in a cohort are represented by an average size. This situation does not occur, and the importance of individual variability in growth lies in the fact that size dispersion can significantly affect the economic performance of a company, especially in species that are marketed by size (as in shrimp). In addition, organisms are susceptible to being harvested not only once, but through a partial harvest strategy. Thus, the risk study could include the individual heterogeneity of the phenomenon more efficiently by using the coefficient of variation or growth rate variation. Studies combining deterministic models –​structured to size and stochasticity in growth rates –​could be a good alternative since individuals of the same size reach different growth rates that could be described by the fits of a likelihood function. 11.2.5  Uncertainty associated with the market and financial institutions

In aquaculture, this type of uncertainty is particularly expressed through variations in price, cost (product and inputs), and financial capacity. Commonly, reduced demand or competition contributes to a decrease in price for the industry, resulting in low sales revenue. For a producer, the increase in input costs (food, energy, seed equipment, among others) produces a decrease in economic benefits. Likewise, a limited supply of inputs increases financial risks. A particular case in this regard occurred in Hawaii with the Hawaiian moi (Polydactylus sexfilis) hatchery. This activity has high risks due to the incompatibility between the supply of fry and the production levels needed to be profitable. One solution to these difficulties has been “vertical integration” through the development of hatchery production.5 This procedure seeks new alternatives for the industry, which are not exempt from causing risks. This helps producers make new investments (capital, operation, feed, and equipment) and it is feasible for companies to get into debt, which depending on interest rates, capital structure, inflation, and other economic aspects, may cause new financial losses. 11.2.6  Uncertainty associated with institutional aspects

Other sources of uncertainty that have a strong impact on aquaculture development are social and political conditions. At the socioeconomic level, its implementation and stability may be affected by society’s attitudes or behaviour towards the activity. Commonly, innovation and transfer in aquaculture are not a task that

180  Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell ensures the success of the activity. In many cases, when technology is transferred, mainly in rural areas, the possibility of failure is due to a lack of understanding and identification of the basic needs of the “target population”, which complicates the adoption of the new activity. Another important element is its expansion. Normally, this activity requires a series of resources for its development, mainly space. This expansion is slowed down by the constant competition from other equally important industries, which even can be a priority for the state and also antagonistic to aquaculture (i.e. recreational tourism and maritime traffic). Finally, at the political level, its development can be slowed down by a series of economic policies reflected in new interest rate applications for producers, imposition of tax incentives, trade restrictions, and environmental policies. If poorly implemented, these policies can contribute to risk as they can be increasingly demanding, costly in terms of time, and subject to change. 11.2.7  Uncertainty of undetermined origin

This type of uncertainty is especially dangerous because of the processes or factors that may exist. This uncertainty is not only difficult to control but can also be absolutely ignored. These sources constitute “surprises” that if an ongoing production system is considered, it can have negative and disastrous effects on the fulfilment of the expected objectives at the end of the production process. Previously reached commitments are implied and may not be fulfilled, especially in key performance indicators defined by the decision-​makers themselves. The unpredictable nature of these factors highlights the importance of planning, constant monitoring, and implementing sound management practices in aquaculture. The following are some examples of the uncertainty of undetermined origin in aquaculture production. a Climate conditions and changes: Changes in climate can affect water temperature, rainfall patterns, and water quality, which in turn can influence aquatic organisms’ health and growth. Extreme weather events, such as storms, floods, or droughts can have a significant impact on aquaculture production b Diseases and pests: Diseases and pests are a constant challenge in aquaculture production. The presence of infectious diseases or pests in aquaculture crops can cause a decline in organisms’ health and growth and even massive population loss. c Water quality: Water quality is a crucial factor in aquaculture production. The presence of contaminants, such as chemicals or excess nutrients, can negatively affect aquatic organisms’ health. In addition, changes in water parameters, such as pH, salinity, or dissolved oxygen concentration can have detrimental impacts on production. d Price fluctuations: Prices of aquaculture products can be affected by unpredictable economic factors, such as changes in supply and demand, variations in production costs, trade policies, or geopolitical situations. These fluctuations can generate uncertainty in the profitability of aquaculture production.

Aquaculture: uncertainty sources and risk quantification methods  181 e Government regulations and policies: Changes in government regulations and policies can influence aquaculture production. For example, the imposition of new environmental or sanitary restrictions, modification of production limits, or the implementation of trade tariffs can have a significant impact on the viability and profitability of aquaculture operations. 11.2.8  Uncertainty in bioeconomic models for projection purposes

The sources of uncertainty in a bio-​mathematical model that is used for production control purposes, and evaluation of key performance indicators (KPIs), such as production and economics, may vary depending on the context and the specific elements of the model. However, some common sources of uncertainty can be identified. Among them, the following points are highlighted:

• Incomplete or inaccurate data: Uncertainty in the input data used in a

bioeconomic model can come from inaccurate measurements, rough estimates, or missing data. These limitations can affect the accuracy and reliability of model results. • Approximations and simplifications: Bioeconomic models often require simplifications to make the problem tractable and feasible. These simplifications can introduce uncertainty due to the lack of full representation of the complexity of the real system. In addition, the numerical approximations used in the calculations can also generate uncertainty. For example, in this area, three important elements can be identified to take into account: a Generalisations: Predictive models often rely on assumptions and generalisations to simplify and represent the target system. However, these assumptions may not be fully accurate or applicable in all situations, which introduces uncertainty in the model results. b Parameters and coefficients: Mathematical models involve the selection of parameters and coefficients that quantify the relationships between model variables. These values may not be known with certainty and may require estimates based on limited data or assumptions. The choice of these parameters introduces uncertainty into the projections of the bioeconomic model. c Human behaviour: If a model incorporates human behaviour, as in economic or decision-​making models, uncertainty may arise from variability in people’s choices and actions. Accurate prediction of human behaviour can be difficult due to the complexity and uncertainty inherent in individual and collective decisions. d Future conditions and unpredictable events: Mathematical models project outcomes based on conditions and events known at the time they are constructed. However, future conditions and unpredictable events can generate uncertainty in model results, including changes in the environment, governmental policies, economic fluctuations, or other unforeseen external factors.

182  Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell It is important to recognise that uncertainty is inherent in bioeconomic models and not all uncertain aspects can be controlled or quantified. Understanding the sources of uncertainty and performing sensitivity and robustness analyses can help assess the impact of uncertainty on model results. 11.3  Techniques for quantifying risk in aquaculture Quantification of risk and uncertainty in aquaculture involves assessing and measuring the probability and impact of future events or conditions that could affect the production and economic performance of aquaculture operations. To do so, it is essential to identify, estimate, quantify, and evaluate uncertainty and the consequences of its occurrence.6 Regularly, the result is shown by means of a technical solution where a level of risk occurrence quantifying a situation is considered unacceptable given the uncertainty of the environment or an acceptable situation. Thus, risk analysis aims to quantify the “uncertainty” for use in calculating the probability of achieving the desired objective and/​or incurring undesirable events. One of the most widely used approaches to meet these objectives has been through decision theory. Decisions are compared between possible different states of nature that would affect the system. That is, a situation where the outcome (performance) of an individual decision depends on the action of another agent (state of nature or source of uncertainty) over which one has no control. Currently, different methods are involved in these principles, which include sensitivity analysis, stochastic modelling, scenario analysis, and the Bayesian method, among others. The following is a detailed description of each of these methods. 11.3.1  Sensitivity analysis

The sensitivity analysis is an important tool for assessing the risks associated with aquaculture and understanding their impact on financial and operational results. This type of analysis is a technique for evaluating how changes in certain variables or parameters may influence the results of an aquaculture project activity or proposal. In the case of aquaculture, these variables may include (i) product prices; (ii) production costs; (iii) production volumes; (iv) mortality rates of cultured organisms; and (v) other relevant factors. First, the sensitivity analysis helps to identify the key variables that have a significant impact on the results of the indicators defined as targets by the decision-​maker. By running different scenarios and variations of these key variables, estimates of the possible ranges of outcomes may be obtained, allowing a better understanding of the level of risk and uncertainty associated with the targets. Thus, assessing the robustness of the activity in the face of different conditions is possible. Another important point is that by generating key changes identified as uncertainty, it is important to know which aspects of the productive activity may be more sensitive to fluctuations in the environment and, therefore, require greater attention and planning to reduce their negative impact. For example, if the analysis shows that salmon production in a particular climatic season is very sensitive to variations in

Aquaculture: uncertainty sources and risk quantification methods  183 sale prices, the adoption of diversification strategies or implementing long-​term contracts can be considered to mitigate the risk of price volatility. This technique also provides a solid basis for the design of risk management strategies in aquaculture. By understanding how certain events or changes in key variables can affect outcomes, more effective risk mitigation strategies can be developed. For example, if variability in the mortality rate of cultured organisms is identified as a major source of risk, more rigorous management practices can be implemented, such as improvements in water quality, disease control, and ongoing monitoring of organism health. In terms of strategic decision-​making in aquaculture, this approach allows different scenarios to be explored and their impact on objective outcomes to be evaluated. Decision-​makers can also evaluate the feasibility of different alternatives and optimise resource allocation, which is especially relevant when considering capital investments, expansion of production, or the introduction of new species. 11.3.2  Stochastic models: Monte Carlo simulation

Proper management of risk and uncertainty is essential in aquaculture to ensure long-​term profitability and sustainability. By considering the random nature of events and variables that influence aquaculture, stochastic analysis has become a powerful tool for assessing and quantifying these risks and uncertainties. Stochastic modelling uses random variables to model and analyse uncertain phenomena, as in aquaculture to simulate various scenarios based on changes of key variables, such as product prices and volumes, organism growth rates, and environmental factors. Monte Carlo simulation models are one of the main applications of stochastic analysis in aquaculture. These models produce numerous random scenarios, assigning probability distributions to the main or key aquaculture variables. By performing several simulation iterations, a wide range of possible outcomes can be obtained, allowing the probability of occurrence of various events to be assessed and the risks associated with them to be quantified. They are also used to calculate measures of performance and risk, such as expected value, standard deviation, and confidence intervals. These measures provide a quantitative view of risk and uncertainty in aquaculture and help decision-​makers evaluate different strategies and scenarios. In addition, the stochastic analysis allows the sensitivity of the results to be evaluated through stochastic sensitivity analysis. In this approach, the probability of distributions assigned to key variables is different to assessing how these variations affect outcomes and risk exposure, which helps to identify the most influential variables and develop more effective risk mitigation strategies. 11.3.3  Scenario analysis

Scenario analysis is a technique for examining and evaluating different hypothetical situations or scenarios that may occur in an economic activity. In the context of aquaculture, it involves the construction of scenarios that represent different combinations of key variables, including product prices, environmental changes,

184  Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell variations in market demand, and other relevant factors. The application of scenario analysis to quantify risk and uncertainty in aquaculture involves the following steps: 1 Identification of key variables: The identification of key variables or uncertainty variables is a relevant step in the application of scenario analysis because they will have an important effect and relative importance on the results, for example, of the profitability or viability of a particular aquaculture activity. Among the relevant variables are sales prices, production costs, climatic conditions, government regulations, and changes in market demand, among others. 2 Scenario building: A second step is the definition of hypothetical scenarios that represent unique combinations of values for the identified variables, considering scenarios related to sales prices of the target aquaculture product, growth rates of the organisms, changes in water quality, etc. Each scenario should be credible and representative of a likely future situation. 3 Evaluation of the effects: Each proposed scenario should be analysed to know the effect on the economic performance, productivity, or viability of an aquaculture project. For example, the target values for revenues, costs, profitability, and other relevant indicators should be assessed in each scenario to understand how changes in key variables may influence economic performance and the associated risks. 4 Identification of risks and opportunities: When the different scenarios are analysed, the risks and opportunities associated with each should be identified. For example, some scenarios may present increased risks due to unfavourable changes in sales prices or adverse environmental conditions. Other scenarios may represent opportunities for improved profitability due to favourable changes in market demand or production efficiency, to name a few. 5 Developing risk management strategies: Using the results of the scenario analysis makes it possible to develop more effective risk management strategies. For example, if high-​risk scenarios are identified, mitigation measures can be considered, such as diversifying the products grown, implementing more robust management practices, or securing long-​term sales contracts, to name a few. Similarly, favourable scenarios that were previously identified can be leveraged to take advantage of growth opportunities and maximise profitability. 11.3.4  Bayesian method

The Bayesian method quantifies and manages uncertainty by incorporating new information and updating estimates as additional data become available. This statistical approach relies on Bayes’ theorem to update initial estimates as new relevant information becomes available. In the context of aquaculture, the Bayesian method is used to quantify uncertainty and assess risks by combining observed data with prior knowledge or initial assumptions. The essential steps in carrying out the application of this approach are as follows:

Aquaculture: uncertainty sources and risk quantification methods  185

• Definition of initial distributions: Initial probability distributions should be

•

•

•

•

defined for the variables of interest, such as crop yields, sales prices, production costs, etc. These distributions can be based on historical data, expert knowledge, or reasonable assumptions. Data collection: Obtaining data is an important action. Data can be collected directly or obtained by designing studies to collect relevant information on the variables of interest or uncertainty. This information may include data on crop yields, market prices, environmental conditions, and economic information, among others. Updating distributions using Bayes’ theorem: As new data become available, it is necessary to update the initial distributions using Bayes’ theorem. This update combines the initial distributions with the likelihood function of the observed data to obtain a posterior distribution that better reflects the updated knowledge. Sensitivity and scenario analysis: Once the a posteriori distributions have been obtained, it is necessary to perform a sensitivity and scenario analyses with them to evaluate how the different combinations of values in the variables of interest affect the results and decision-​making. Risk assessment and decision-​making: Having solved the above where the posterior distributions and the results of the sensitivity analysis were incorporated, the risks associated with different decisions or strategies may be assessed. This step not only allows one to make informed decisions but also designs more effective risk management strategies.

11.4  Risk and uncertainty studies in aquaculture In recent years, the quantification of risk and uncertainty in aquaculture has become an important milestone to address, especially when informed decision-​making is required to help the activity’s sustainability, improving and optimising its processes. So far, a series of studies applied to the aquaculture activity have been carried out, which include different species of commercial interest and techniques to quantify risk and uncertainty. The following is a description of some case studies where the different methods previously described are addressed. When we refer to sensitivity studies, they are generally associated or reinforced with a stochastic model. This is the case of the study proposed by Ruiz-​Velazco et al.,7 which investigated the profitability, uncertainty, and economic risk associated with different partial harvesting strategies in semi-​intensive commercial production of white shrimp, Litopenaeus vannamei. The authors recognise that uncertainty and risk are important factors to consider when making decisions in commercial aquaculture. Therefore, the study used sensitivity analysis and stochastic modelling as tools to quantify and evaluate the impact of uncertainty on profitability and economic risk of partial harvesting strategies. The application of these methods to address risk first helped to identify and evaluate how economic outcomes vary in response to changes in key parameters and input variables.

186  Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell The main variables identified as sources of uncertainty were shrimp selling price, production costs, shrimp growth rate, and feed conversion rate. The sensitivity analysis determined that the shrimp sales price and production costs had a significant impact on the profitability and economic risk of the activity. In molluscs, for example, Theodorou and Tzovenis8 provided a practical tool for assessing and managing the risks associated with mollusc aquaculture in coastal Greece. These authors determined that this aquaculture activity is exposed to a number of risks and uncertainties, which have a significant impact on the production and profitability of operations. The study addresses the problem by implementing a systematic approach to identify, assess, and mitigate these risks. This risk approach was based on a combination of qualitative and quantitative risk assessment. Sensitivity analysis tools, through the study of historical data, were used. This method was strengthened by including the identification of hazards and vulnerabilities, estimation of probabilities of adverse events, and impact and consequences analysis. The data collected corresponded to environmental conditions, cultivation practices, and markets, which were among the most important. The main risks associated with mussel farming were also identified and their potential impacts in terms of production and profitability were assessed. Finally, this risk quantification provided a comprehensive view of the risks and uncertainties facing mussel aquaculture in the Mediterranean region of Greece, allowing producers and decision-​makers to implement more effective risk management strategies and take measures to reduce vulnerability and improve the resilience of the industry. On investment issues associated with aquaculture production, Landazuri-​ Tveteraas et al.9 examined the determinants of investment behaviour in salmon aquaculture in Norway, including how risk and uncertainty are quantified. This study used a quantitative approach to analyse the determinants of investment decisions in salmon aquaculture. To quantify risk and uncertainty, the authors applied sensitivity analysis and econometric modelling. The sensitivity analysis was used to assess the impact of various variables on investment decisions, which involved identifying key factors affecting profitability and risk in salmon aquaculture, such as market prices, production costs, resource availability, and regulatory changes. Econometric models were used to analyse the relationship between these factors and investment decisions. These models considered the relationship between economic and financial variables, and how they influence the profitability and risk of salmon aquaculture investment. In addition, a scenario analysis was conducted to assess the impact of possible future changes in key variables, such as market prices or production costs. These results helped industry stakeholders to better understand the implications of different scenarios and make informed decisions. Regarding the use of stochastic models, it is interesting to mention that they are the most employed methods to address risk or their combination with other methodological approaches. Moor et al.10 addressed the issue of the financial viability of shellfish aquaculture through the use of stochastic models. According to the authors, shellfish aquaculture faces numerous challenges, including variability in product prices, production costs, and environmental factors. These uncertain factors can have a significant impact on the profitability and sustainability of

Aquaculture: uncertainty sources and risk quantification methods  187 aquaculture operations. To address the problem, the researchers used a stochastic modelling approach, which allowed them to capture variability and uncertainty in the different economic and environmental parameters related to mollusc aquaculture. The authors used advanced statistical techniques (Monte Carlo modelling) to simulate multiple scenarios and analyse financial outcomes as a function of different variables and assumptions. The results of the study provided important information on the risks and uncertainty associated with shellfish aquaculture and allowed industry stakeholders to make more informed and strategic decisions Considering the effect of climate change, Sheng et al.11 evaluated the profitability of freshwater aquaculture in China. The study focused on quantifying the risk and uncertainty associated with these impacts. To quantify risk and uncertainty, the authors used an approach based on economic and stochastic simulation models. First, they developed an economic model to assess the profitability of freshwater aquaculture under different climate scenarios. This model considered key economic variables, such as production costs, selling prices of aquaculture products, and market demand. They also used simulation techniques to generate multiple climate scenarios and evaluate the impact of these scenarios on aquaculture profitability. These climate scenarios considered different relevant climatic variables, such as water temperature, precipitation patterns, and availability of natural resources. The results of this research allowed identifying the most vulnerable geographical areas and time periods, as well as estimating the potential economic losses in freshwater aquaculture in China. Considering the open sea, Jin et al.12 present an approach based on an investment and production model at the enterprise level to quantify risk and uncertainty. This study focuses on the risk analysis associated with open-​water aquaculture investment, considering both economic and biological factors. To quantify risk and uncertainty, the authors used a bioeconomic modelling approach that integrates several variables and scenarios. As economic variables, they considered investment costs, operating costs, sales prices of aquaculture products, and interest rates. Among the biological variables, the main sources of uncertainty were the growth rate of cultured species, mortality, reproduction, and feed availability. These biological factors are inherently uncertain and vary in different scenarios, which adds another dimension of uncertainty to the risk analysis. The final model estimates the financial and biological risks associated with investing in open-​water aquaculture. The model also simulates different scenarios and calculates risk measures, such as the probability of underperforming or suffering economic losses in open-​water aquaculture. The uncertainty associated with diseases and their economic effect on the activity is another important milestone in the application of the risk approach. Hernandez-​ Llamas et al.13 present an approach to quantify risk and uncertainty in intensive aquaculture of Litopenaeus vannamei. These authors address the economic risk associated with white spot disease, as well as stochastic variability in economic, zootechnical, and water quality parameters, affecting intensive white shrimp production. To quantify risk and uncertainty, the authors used an approach that combines economic analysis and stochastic modelling. First, an economic analysis

188  Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell was conducted to evaluate the costs and benefits associated with intensive white shrimp production, considering factors, such as production costs, selling prices, growth rates, and mortality. These economic factors were then used to estimate the profitability and financial risk of shrimp aquaculture. In addition, stochastic variability in zootechnical and water quality parameters influencing production was incorporated. Uncertainty in growth rate, mortality rate, and dissolved oxygen levels in the water were also considered. These parameters were modelled using probability distributions to reflect their random nature. Using stochastic simulation techniques, the authors generated multiple scenarios that allowed the calculation of risk measures, such as the probability of economic loss or failure to meet production targets. This provided a better understanding of potential risks that allow producers to make informed decisions for optimal shrimp aquaculture management considering the presence of the disease. Risk analysis has also been used to compare technologies for production use. Engle and Sapkota14 conducted a comparative analysis of economic risk in the production of striped bass hybrid fingerlings in ponds and indoor tanks. To quantify risk and uncertainty, the authors used the Monte Carlo simulation approach. This method is based on the generation of multiple random scenarios to represent variability and uncertainty in key study variables, such as production costs, selling prices, and fry growth rate. For each of the scenarios, the economic performance of striped bass hybrid fry production was estimated considering the technology with ponds and indoor tanks. To strengthen the results, the authors also considered other indicators of economic risk, such as volatility and sensitivity of the results to changes in key variables, which provided a more complete picture of the risks associated with fingerling production. In the same area, Seijo15 addresses the risk of exceeding bioeconomic limits in shrimp aquaculture systems. To quantify risk and uncertainty, this author uses an approach based on the theory of decision-​making under uncertainty. In particular, the concept of “bioeconomic reference points” is used to assess the risk of exceeding certain critical limits that could have negative impacts on the sustainability and profitability of shrimp aquaculture systems. The method used involved the construction of a bioeconomic model that relates key variables such as sales prices, production costs, shrimp growth rate, and the carrying capacity of the system. From this model, bioeconomic reference points were established that represent critical thresholds to which attention should be paid to avoid significant risks. Using this information, a stochastic-​sensitivity analysis was performed and different sources of uncertainty were introduced into the model, such as market price, production costs, and environmental conditions. By simulating scenarios and generating multiple random realisations of these variables, the risk of exceeding the bioeconomic benchmarks was evaluated. Through the simulation of the results, the probability of shrimp aquaculture systems exceeding the established critical limits can be determined. This simulation provides valuable information for decision-​ making in shrimp aquaculture, identifying appropriate management strategies and policies to mitigate risk and ensuring the economic sustainability of the systems.

Aquaculture: uncertainty sources and risk quantification methods  189 Regarding the application of scenario analysis, Yakabu et al.16 use scenario analysis and land use change modelling to assess the opportunities and challenges of sustainable aquaculture expansion in Nigeria. This study recognises the importance of considering multiple factors, such as the availability of suitable land, production capacity, and socioeconomic aspects, when assessing the potential for aquaculture expansion in Nigeria. Through the scenario analysis, different possible future conditions were explored, and the expected impacts in terms of aquaculture production and land use change were assessed. Land use change modelling simulated and predicted aquaculture expansion patterns under different scenarios. With these results, the most suitable areas could be identified for the location of aquaculture farms and to evaluate possible land use conflicts and associated environmental impacts. Another case was conducted by Couture et al.,17 where this type of approach was used; these authors present a study using scenario analysis as a tool to guide aquaculture planning and achieve sustainable production objectives. The authors demonstrated that multiple factors should be considered, such as the availability of suitable marine areas, environmental impacts, market demand, and regulatory policies to plan for future growth of marine aquaculture. Using the scenario analysis, they explored different combinations of factors and evaluated the expected outcomes in terms of aquaculture production and sustainability. This approach made it possible to examine a wide range of future possibilities and assess how different decisions and conditions might influence the achievement of sustainable production goals. In addition, they identified barriers and opportunities associated with each scenario, which provided valuable informed decision-​making, especially for marine resource managers and stakeholders involved in the aquaculture industry as decision-​ makers. Regarding the Bayesian approach, Hadley et al. provide a Bayesian approach to quantify and address uncertainty in a macroalga-​based integrated multi-​trophic aquaculture model. The authors identified as sources of uncertainty model parameters and variability in the observed data. These two sources were treated using the Bayesian approach by combining prior information and observed data to obtain accurate and probabilistic estimates of model parameters and predictions. The application of this approach finally facilitated the sensitivity analysis to evaluate the relative influence of different sources of uncertainty on model predictions. This analysis provided valuable information to understand which variables and parameters have the greatest impact on the results and how they can be most effectively managed. Furthermore, the ability of managers and decision-​makers to assess the risks and viability of production systems improved. Randall et al.18 also used the Bayesian method, combining this approach along with mining data to assess risk and uncertainty in rice and shrimp aquaculture in Vietnam. The authors developed a mathematical model to analyse the relationship between various variables and estimate the probability of occurrence to discover hidden patterns and relationships in the data, which contributed to a better understanding of the factors influencing yield and production in rice and shrimp aquaculture in Vietnam.

190  Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell 11.5  New techniques for risk management in aquaculture: machine learning and artificial intelligence (AI) In recent years, the use of machine learning and AI techniques in aquaculture risk management has gained popularity because of their ability to analyse large data sets, identify patterns, and make predictions. These techniques can help quantify risk and uncertainty by providing more accurate and sophisticated analyses. According to Aziz and Dowling19 the process of using machine learning and AI to quantify risk involves the following steps:

• Data collection: Relevant aquaculture-​related data are collected, such as pro• • • • •

•

duction, environmental, and market data, besides other factors that may affect the performance and profitability of aquaculture systems. Data preparation: Collected data are processed and prepared for analysis, which involves data cleaning, removal of outliers, and data normalisation if necessary. Feature selection: The most relevant features or variables to be used for analysis are selected, which may include variables related to water quality, temperature, production costs, market prices, among others. Model building: A machine learning or AI model is built using appropriate algorithms. These algorithms analyse the data and learn patterns and relationships between variables to make predictions and decisions. Model training and validation: The model is trained using historical data and validated using separate data sets to assess its accuracy and performance. Prediction and risk assessment: Once the model has been trained and validated, it can be used to make predictions and assess risk, which involves using current data to predict possible scenarios and risks associated with aquaculture, such as disease probability, crop yields, and production costs, among others. Risk management: Based on model results and predictions, informed decisions can be made to mitigate risk in aquaculture, which may include adjustments in management practices, implementation of biosecurity measures, optimisation of resources, and strategic planning.

Among the recent studies applying machine learning and AI is Yang et al.20. This study addresses the importance of machine learning tools in the context of risk assessment and safety in aquaculture operations. In the aquaculture industry, appropriate operational limits should be established to ensure the safety of systems and minimise the risks associated with operations. These operational limits are defined based on a variety of factors, such as environmental conditions, the health of cultured organisms, and the availability of resources, among others. The research highlights that machine learning tools play a key role in determining these operational limits, since they can analyse large volumes of data and extract relevant information for decision-​making. Machine learning can identify complex patterns and relationships in the data collected from aquaculture operations, which helps to better understand the potential risks and

Aquaculture: uncertainty sources and risk quantification methods  191 critical areas that require attention. According to the authors, the main advantage of applying this approach is that it allows for a more accurate and objective assessment of risks by taking into account multiple interrelated variables and factors. In addition, early signs of potential problems or adverse events can be identified, providing a faster and more effective response to mitigate risks. Another highlight of this work is the ability of machine learning to continuously improve risk and safety models in aquaculture. As more information is collected and data are updated, machine learning algorithms can adapt and improve their predictive capability, contributing to more efficient and accurate risk management In the same field, Gladju et al.21 present a comprehensive review of the applications of data mining and machine learning framework in aquaculture and fisheries. According to the authors, in the field of aquaculture and fisheries, the use of data mining and machine learning has become increasingly important due to its ability to analyse large volumes of data and extract valuable information. This statement is in line with the previously described work, which also highlights that these technologies can improve efficiency, productivity, and sustainability in these sectors. Likewise, the techniques demonstrate their capacity in the detection and prediction of diseases and pests in cultivated organisms, where identifying patterns and early signs of diseases are also possible, allowing a rapid and precise response to control their spread and minimise losses. Another highlight is the application in feed and nutrition optimisation processes in aquaculture. These techniques can analyse data related to water quality, feed composition, and organism growth to develop customised feeding models that maximise feed efficiency and reduce costs. Finally, the techniques can be applied in supply chain management and marketing of aquaculture and fishery products. Moreover, they can analyse market data, consumer preferences, and economic factors to improve decision-​making in product marketing and promotion. 11.5.1  Facing uncertainty, a sustainable perspective

The risk analysis not only has an estimation of reaching a certain probability of success or failure in culture, but when well-​applied, it is a powerful tool to focus on future efforts to prevent risk and reduce the sources of uncertainty. In effect, as a product of resampling the interest variables have a variance, which may be explained in different percentages for each one of the uncertainty sources. For example, a variance of 100% w% can be explained for natural mortality, x% probability of appearance of catastrophic diseases, y% variability in growth, z% environmental variability, and so on. In this scheme, if the variables that are sources of uncertainty follow a hierarchical order from those that most contribute to the final variance (which is the risk likelihood), they may be developed, and some policies directed to reduce them may be applied. Thus, the priority selection of inversion (i.e., in technology or future studies that limit the uncertainty in such variables) contributes to the financial success of aquaculture. This priority selection may, in turn, have a significant

192  Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell impact on the performance of aquaculture activities, not only from an economic point of view but also environmental and social. As an example, the use of risk analysis applying a sustainable vision can be seen in the work of Peñalosa Martinell.22 The author developed a risk analysis from the point of view of sustainability adding a series of environmental and social characteristics to the classical economic parameters to evaluate the performance of white shrimp larval production with and without the use of new technologies. In turn, the author evaluated the impact that the application of the current public policies in Mexico has associated with aquaculture production and its implication on greenhouse gas emissions. For this purpose, an indicator was selected for each one of the sustainability spheres (CO2 emission for the environment; benefits per cycle for the economy; and a point of social equilibrium for society). Then, a risk analysis was used jointly to evaluate the probabilities to reach a series of goals. The author concluded that when the existent subsidy was currently transferred from the energy application to implement eco-​friendly technologies (such as the use of probiotics in shrimp larva production), the risk of not reaching the point of social equilibrium is reduced significantly. 11.6  Final remarks Risk analysis is a technique that originated in the world of finance, and its application has developed towards risk reduction to maximise financial returns. However, efforts and tools have been initiated to find solutions to improve the performance of the industry not only from an economic but also sustainable point of view. Due to the number of variables and parameters involved, aquaculture systems are highly complex, which makes the productive dynamics and success or failure of the activity difficult to predict in terms of both sustainability and economics. In addition to the above, these systems are subjected to high intrinsic biological variability of the species, environmental and technological, among others. This situation frequently leads to unforeseen events for which adequate and effective responses are not always available. All this variability means that decision-​making based solely on empirical experience only introduces new sources of uncertainty in the success of the activity. All of the above makes aquaculture a high-​risk activity. Bioeconomic systems modelling has emerged as an effective platform to address the need for decision-​making when cognitive resources are limited. These models analyse the complexity of aquaculture systems, evaluate different scenarios and strategies, and make informed decisions to promote sustainable and profitable production in aquaculture. These tools use a systemic approach to understand and interrelate all aspects that influence aquaculture production (biological-​ecological, technological, management methods, and economic, such as market characteristics, profitability, or investment decisions). However, the need to identify the main sources of uncertainty in aquaculture is essential in this process. The description and knowledge of the main sources of uncertainty in aquaculture, presented in this chapter, are essential for a correct analysis and quantification of risk because they are an important guide for both producers and bioeconomists. In the case of producers, the main sources of uncertainty not only help to avoid making decisions under

Aquaculture: uncertainty sources and risk quantification methods  193 assumptions of certainty or based solely on previous experience, but also recognise the likely effects on production decision-​making. For economists, incorporating these elements into quantitative formulations helps them to incorporate stochastic scenarios into aquaculture programmes (optimisation and simulation), incorporate reference points (targets and limits), and determine the probabilities of success or failure in aquaculture projects or alternative harvesting and production techniques. To quantify risk and uncertainty in aquaculture, sensitivity analysis methods, stochastic models, scenario analysis, and Bayesian methods have become fundamental tools. These methodologies help to evaluate the impact of different variables and scenarios, identify the main sources of risk, and make informed decisions to effectively manage the risks associated with the activity. The sensitivity analysis is particularly relevant, since it helps to understand how the model results change when key or uncertainty inputs are varied, which allows identifying the most influential and sensitive variables and focusing management and control efforts to minimise risk. Stochastic models and scenario analysis help to incorporate the inherent uncertainty in aquaculture and evaluate possible outcomes under different conditions. These tools improve the understanding of the variability and limits of the production systems, which is crucial for making informed and adaptive decisions. On the other hand, the Bayesian method combines previous information and new evidence to update risk estimates and make decisions based on probabilities. This approach allows for more rigorous risk assessment by using updated information to improve decision-​making. As a means to strengthen the previous techniques and the bioeconomic models where these techniques are applied, we have currently used and implemented new information technologies such as machine learning and artificial intelligence. These methods are revolutionising risk assessment and management in aquaculture. These technologies make it possible to analyse large volumes of data, identify patterns and trends, and make more accurate predictions about the behaviour of aquaculture systems. They definitely help to anticipate and mitigate risks, optimise operations, and improve the profitability and sustainability of aquaculture. To address and apply the above, a logical sequence of steps should be established to correctly address risk assessment in aquaculture. The following is a basic outline that aims to provide a general and simplified overview of the process for analysing risk and uncertainty in aquaculture (Figure 11.1). In practice, more detailed and specific approaches may be required depending on the particular situation, however, this basis could guide and enhance this analysis itself. 1 Risk identification: • Identify potential adverse events that could affect aquaculture production. • Consider biological, environmental, economic, social, and regulatory risks. 2 Uncertainty analysis: • Identify sources of uncertainty in aquaculture, such as price fluctuations, changes in environmental conditions, etc. • Assess the magnitude and extent of uncertainty associated with each source.

194  Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell

Figure 11.1 Basics steps of the risk analysis and uncertainty in aquaculture.

3 Risk assessment:

• Assess the probability of occurrence of identified adverse events. • Evaluate the potential impact of the events on aquaculture production and operations.

4 Risk mitigation:

• Develop strategies and measures to reduce the probability of occurrence of adverse events.

• Implement appropriate management practices, such as sanitary protocols, early warning systems, species diversification, etc.

5 Continuous monitoring and review:

• Regularly monitor relevant conditions and variables. • Evaluate the effectiveness of implemented risk mitigation strategies. • Make adjustments and improvements to management strategies based on changes and lessons learned.

6 Communication and decision-​making:

• Communicate the results of the risk and uncertainty analysis to stakeholders. • Use the information obtained to make informed and strategic decisions in aquaculture management.

Aquaculture: uncertainty sources and risk quantification methods  195 11.7  Chapter review questions 1 2 3 4

What is a risk and how can we manage it? Can risk be managed without historical data? Which are the most common types of risk? Can we use risk analysis and management to improve the sustainability of the aquaculture industry?

Recommended readings Bondad-​Reantaso, M. G., Arthur, J. R., & Subasinghe, R. P. eds. (2008). Understanding and Applying Risk Analysis in Aquaculture. Rome: Food and Agriculture Organization of the United Nations. Engle, C. R. (2010). Aquaculture Economics and Financing: Management and Analysis. John Wiley & Sons. Ezondu, E. S., & Anyanwu, P. E. (2005). Potential hazards and risks associated with the aquaculture industry. African Journal of Biotechnology, 4(13). Kam, L. E., & Leung, P. (2008). Financial risk analysis in aquaculture. Understanding and Applying Risk Analysis in Aquaculture, 153. Rahman, M. T., Nielsen, R., Khan, M. A., & Ahsan, D. (2021). Perceived risk and risk management strategies in pond aquaculture. Marine Resource Economics, 36(1), 43–​69. Rausand, M., & Haugen, S. (2020). Risk Assessment: Theory, Methods, and Applications. Wiley. Rico, A., & Van den Brink, P. J. (2014). Probabilistic risk assessment of veterinary medicines applied to four major aquaculture species produced in Asia. Science of the Total Environment, 468, 630–​641.

References 1 Bondad-​Reantaso, M. G., Arthur, J. R., Rohana, P. Subasinghe, eds. Understanding and Applying Risk Analysis in Aquaculture. Italy: Food and Agriculture Organization of the United Nations, 2008. 2 Taha, H. A. Investigación de operaciones. Novena edición. México: PEARSON EDUCACIÓN, 2012. ISBN: 978-​607-​32-​0796-​6 3 Albright, S. C., Winston, W. L. 2016. Business Analytics: Data Analysis & Decision Making –​Standalone book 6th edition. Boston, MA: Cengage Learning. 4 Caddy, J. F., Mahon, R. Reference points for fisheries management. FAO Fisheries Technical Paper. No. 347. Rome, FAO. 1995. 83p. 5 Kam, L. E., Leung, P. S., Ostrowski, A. C., Molnar, A. 2002. Size economies of a Pacific threadfin Polydactylus sexfilis hatchery in Hawaii. Journal of World Aquaculture Society, 33, 410–​424. 6 Luna, M., Llorente, I., Luna, L. 2023. A conceptual framework for risk management in aquaculture. Marine Policy, 147, 105377. 7 Ruiz-​Velazco, J. M., González-​Romero, M. A., Estrada-​Perez, N. 2021. Evaluating partial harvesting strategies for whiteleg shrimp Litopenaeus (Penaeus) vannamei semi-​intensive commercial production: Profitability, uncertainty, and economic risk. Aquaculture International, 29, 1317–​1329 .https://​doi.org/​10.1007/​s10​ 499-​021-​00695-​5

196  Marcelo E. Araneda Padilla and Daniel Peñalosa Martinell 8 Theodorou, J. A., Tzovenis, I., 2023. A framework for risk analysis of the shellfish aquaculture: The case of the Mediterranean mussel farming in Greece. Aquaculture and Fisheries, 8, 375–​384. https://​doi.org/​10.1016/​j.aaf.2021.04.002 9 Landazuri-​Tveteraas, U., Misund, B., Tveterås, R., Zhang, D. 2023. Determinants of investment behavior in Norwegian salmon aquaculture. Aquaculture Economics & Management, 6, 1–​19. doi: 10.1080/​13657305.2023.2208541 10 Moor, J., Ropicki, A., Anderson, J. L., Asche, F. (2022). Stochastic modeling and financial viability of mollusk aquaculture. Aquaculture, 552, 737963. 11 Sheng, L., Yang, Z., Nadolnyak, D., Zhang, Y., Luo, Y. 2014. Economic impacts of climate change: Profitability of freshwater aquaculture in China. Aquaculture Research, 47, 1537–​1548. 12 Jin, D., Kite-​Powell, H., Hoagland, P. 2005. Risk assessment in open-​ocean aquaculture: A firm-​level investment-​production model. Aquaculture Economics & Management, 9(3), 369–​387. doi:10.1080/​13657300500242261. 13 Hernandez-​Llamas, A., Ruiz-​Velazco, J. M. J., Gomez-​Muñoz, V. M. 2013. Economic risk associated with white spot disease and stochastic variability in economic, zootechnical and water quality parameters for intensive production of Litopenaeus vannamei. Aquaculture Research, 5, 121–​131. 14 Engle, C., Sapkota, P., 2012. A Comparative analysis of the economic risk of hybrid striped bass fingerling production in ponds and indoor tanks. North American Journal of Aquaculture, 74, 477–​484. 15 Seijo, J.C. 2004. Risk of exceeding bioeconomic limit reference points in shrimp aquaculture systems. Aquaculture Economics & Management, 8(3–​4), 201–​212. doi:10.1080/​13657300409380363 16 Yakabu, S., Falconer, L., Telfer, T. 2022. Scenario analysis and land use change modelling reveal opportunities and challenges for sustainable expansion of aquaculture in Nigeria. Aquaculture Reports, 23, 101071 17 Jessica L. C. and others. (2021) Scenario analysis can guide aquaculture planning to meet sustainable future production goals. ICES Journal of Marine Science, 78(3), 821–​ 831. https://​doi.org/​10.1093/​ices​jms/​fsab​012 18 Randall, M., Lewis, A., Stewart-​Koster, B., Anh, N. D., Burford, M., Condon, J. 2022. A Bayesian belief data mining approach applied to rice and shrimp aquaculture. PLoS ONE, 17(2), e0262402. https://​doi.org/​10.1371/​jour​nal.pone.0262​402 19 Aziz, S., Dowling, M. (2019). Machine learning and AI for risk management. In: Lynn, T., Mooney, J., Rosati, P., Cummins, M. (eds) Disrupting Finance. Palgrave Studies in Digital Business & Enabling Technologies. Cham: Palgrave Pivot. https://​doi.org/​ 10.1007/​978-​3-​030-​02330-​0_​3 20 Yang, X., Ramezani, R., Utne, I. B., Mosleh, A., Lader, P. F. 2020. Operational limits for aquaculture operations from a risk and safety perspective. Reliability Engineering & System Safety, 107208, ISSN 0951-​8320. https://​doi.org/​10.1016/​j.ress.2020.107​208 21 Gladju, J., Kamalam, B. S., Kanagaraj, A. (2022). Applications of data mining and machine learning framework in aquaculture and fisheries: A review. Smart Agricultural Technology, 2, 100061, ISSN 2772-​3755,. https://​doi.org/​10.1016/​j.atech.2022.100​061 22 Peñalosa Martinell, D. (2020). Análisis bioeconómico del uso de probióticos en la producción de larvas de camarón blanco (Penaeus vannamei, Boone, 1931): un enfoque sostenible (Doctoral dissertation, Instituto Politécnico Nacional. Centro Interdisciplinario de Ciencias Marinas).

Part IV

Aquaculture and society

12 Aquaculture and food security Fernando Aranceta Garza

Aquaculture allows the constant production of quality protein at affordable prices, and there are success stories where social programmes have been implemented to fill some of the social deficiencies of marginalised communities. Despite the above, there are specific criticisms and challenges that the industry must overcome to become a more widespread solution to strengthen food security and the sovereignty of vulnerable communities. Aquaculture cannot (and shall not) be considered entirely as an alternative to fishing due to its dependence on inputs from the sea that can be fed directly or used in other food production systems. Furthermore, a significant part of global aquaculture production is concentrated in the few profitable species that compete in global markets, so only a fraction of the production strengthens the food security of communities, especially in developing countries. Bearing these factors in mind, the current panorama of the relationship between aquaculture and food security is presented, as well as specific case studies. 12.1 Introduction The 2030 Agenda for Sustainable Development and Sustainable Development Goals (SDGs) requested transformative solutions, integrated approaches, and innovative pathways to attain sustainable development. The fundamental role of sustainable agriculture, forestry, and fisheries was also emphasised in connecting people, the planet, and prosperity to achieve its global goals of ending hunger and poverty through sustainable management and utilisation of natural resources. As shown in the following sections, marine production, both in the fishery and aquaculture sectors, contributes to global food security and nutrition, especially in developing regions, while the livelihoods of millions of people around the globe are also supported. The SDGs comprise 17 global goals where SDG 2, “No Hunger”, directly attends to the needs for food security, improved nutrition, and promoting sustainable agriculture around the globe, especially in undernourished countries such as some in Africa (the region with the highest number of low-​income food-​deficit countries), along with Asia and some countries in Latin America, including the Caribbean. The DOI: 10.4324/9781003174271-16

200  Fernando Aranceta Garza main SDG 2 goal is to end all forms of hunger and malnutrition by promoting sustainable agricultural practices, supporting small-​scale farmers, and providing equal access to land, technology, and markets. At the same time, searching for global cooperation should continue to ensure investment in infrastructure and technology to improve agricultural productivity. This goal also applies to other food production systems, such as the marine and aquaculture sectors, to ensure sustainable practices, ecosystem health, and enhance food production. For the marine systems, SGD 14, “Life below water”, aims to conserve and use the oceans, seas, and marine resources for sustainable development, protect marine and coastal ecosystems from pollution, and strengthen their resilience to climate change, e.g., ocean acidification. Marine and coastal zones contribute largely and could be further enhanced to provide greater food security and nutrition. They cover three-​quarters of the Earth’s surface, where more than 3 billion people (half of the world’s human population) depend on marine and coastal biodiversity for their livelihoods (including food security). 12.2  Matching food security with human population growth The human population is 7.9 billion, and is increasing at a growth rate of 1.05% per year to reach ~9 billion by the 2030s. Globally, the countries with the highest relative populations are China (18.5%) and India (17.7%), followed by the United States (4.2%) (see Figure 12.1).

Figure 12.1 Populations of the 20 most populated countries. Sources: United States Census Bureau –​ International Database 2022 and UN World Population Prospects 2019.

Aquaculture and food security  201 Human population growth (including distribution, composition, and consumption patterns) is impacting the Earth in two major ways: (1) by the consumption of resources such as land, food, water, air, fossil fuels, and minerals and (2) by the production and accumulation of associated waste products, such as air and water pollutants, toxic materials, and greenhouse gases. Moreover, human impact on the Earth has been so significant that it has created a new geologic era, the Anthropocene. Historically, providing food (e.g., hunting, agriculture) and housing to humankind have unavoidably altered the Earth’s ecosystems. The terrestrial environments provide most human dietary energy, comprising ~98% of global calorie production,1 highlighting the relative importance of cereals, followed in descending order of relative importance by oils and fats, roots, tubers and pulses, sugars, meats, fishes, and seafood.2 The increase in demand for resources (e.g., food, fodder, fuel, and raw materials) related to the increase in human population has enhanced land-​use changes and degradation, reducing the amount of productive land available and jeopardising global food security. Currently, farming uses half of all habitable land on Earth and this agricultural intensification has not proven sustainable.1 Reducing the human impact on land to provide global food security can be achieved by increasing sustainable production in aquatic ecosystems, particularly fisheries and aquaculture. Aquaculture has proven to be the world’s fastest-​growing food-​production industry and currently provides half of all the planetary seafood (2018: 82 million tonnes [MT]). Moreover, aquaculture has higher nutritional benefits than land-​based animal production systems3 and lower environmental externalities. For example, aquaculture contributes less per unit weight to global nitrogen and phosphorus emissions, has higher feed conversion ratios, and uses less water.4 Furthermore, promoting recirculating aquaculture system production technologies could increase water use efficiency, enhance biomass production, and reduce wastage and pollution to the minimum. Additionally, aquaculture can help reduce environmental impacts on the aquatic ecosystem, e.g., the cultivation of filter-​feeding bivalve molluscs (i.e., oysters, clams, scallops, and mussels) promotes the filtration of pollutants from the environment. However, as with other food systems, the high demand and productive intensification of aquaculture production also generates environmental externalities. The most common of these are focal eutrophication, acidification, energy demand, climate change, coastal land occupation, and biotic depletion, which vary production among species and technology, with the highest impacts observed in China and Asia (major aquaculture producers). 12.2.1  What is food security?

Food security is defined as a situation that exists when all people, at all times, have physical, social, and economic access to sufficient, safe, and nutritious food that meets their dietary needs and food preferences for an active and healthy life.5

202  Fernando Aranceta Garza Nutrition security is defined as the access to an appropriately nutritious diet coupled with a sanitary environment, adequate health services, and care to ensure a healthy and active life for all household members.6 Four food security dimensions are identified based on the food security definition: availability, access, utilisation, and stability (see Figure 12.2). Availability addresses whether food is actually or potentially physically present, including aspects of production, food reserves, markets and transportation, and wild foods. Once the food is available, access refers to whether households and individuals have sufficient physical and economic access to that food. Utilisation means whether households are maximising adequate nutrition and energy consumption and good feeding practices concerning intra-​household food distribution, clean water, sanitation, and healthcare, which determine the nutritional status of individuals. Finally, if the other three dimensions are met, stability is the condition in which the whole system is stable, thus ensuring that households are food secure. However, instability drivers, such as climatic, economic, social, and political factors can be frequent and variable. The four traditional food security dimensions are measured by the specific indicators shown in Table 12.1. The concept of food security is currently evolving to recognise other dimensions, such as the centrality of agency and sustainability. Agency refers to the capacity of individuals or groups to make their own decisions about what foods they eat and/​or produce; how that food is produced, processed, and distributed within food systems; and their ability to engage in processes that shape food system policies and governance. Sustainability is defined as the long-​term ability of food systems to provide food security and nutrition that does not compromise the economic, social, and environmental bases that generate food security and nutrition for future generations.

Figure 12.2 Traditional food security dimensions. Source: Defined by FAO et al. (2021).

Aquaculture and food security  203 Table 12.1 Food security indicators by dimension Food security indicators

Dimension

Average dietary energy supply adequacy Average food production value Share of dietary energy supply derived from cereals, roots, and tubers Average protein supply Average protein supply of animal origin Percentage of paved roads over total roads Road density Railway density Gross domestic product (in purchasing power parity) Domestic food price index Prevalence of undernourishment (PoU) Share of food expenditure of the poor Depth of the food deficit Prevalence of food inadequacy Cereal import dependency ratio Percentage of arable land equipped for irrigation Value of food imports over total merchandise exports Political stability and absence of violence/​terrorism Domestic food price volatility Per capita food production variability Per capita food supply variability Access to improved water sources Access to improved sanitation facilities Percentage of children under 5 years of age affected by wasting Percentage of children under 5 years of age who are stunted Percentage of children under 5 years of age who are underweight Percentage of adults who are underweight Prevalence of anaemia among pregnant women Prevalence of anaemia among children under 5 years of age Prevalence of vitamin A deficiency in the population Prevalence of iodine deficiency in the population

Availability

Access

Stability

Utilisation

Source: FAO et al. (2015).

Globally, food insecurity is measured using the prevalence of undernourishment (PoU) indicators and the Food Insecurity Experience Scale (FIES). PoU refers to an estimated percentage of individuals in the total population that are in conditions of undernourishment –​the condition of an individual whose habitual food consumption is insufficient to provide, on average, the amount of dietary energy required to maintain a normal, active, and healthy life. Likewise, FIES refers to the limited access to food, at the level of individuals or households, due to the lack of money or other resources. Indicators of undernutrition are based on poor nutritional intake in terms of quantity and/​or quality and poor absorption and/​or biological use resulting from a disease. These indicators include stunting (low height-​for-​age), wasting (low

204  Fernando Aranceta Garza

Figure 12.3 Prevalence of undernourishment by region. Note: Prevalence of undernourishment in Northern America and Europe is less than 2.5%. Values for 2020 are projections. Source: FAO (2021c).

weight-​for-​age), low birth weight, and anaemia in women of reproductive age (micronutrient deficiency: vitamin and minerals). Malnutrition –​ an abnormal physiological condition caused by inadequate, unbalanced, or excessive intake of macro-​and micronutrients –​includes all the undernutrition indicators plus overweight in children under five years old and adult obesity (body weight above the average and excessive fat accumulation). 12.2.2  Food security status around the world

Before the COVID-​19 pandemic, world hunger and malnutrition were already not on track to meet the pre-​established SDGs zero-​hunger goals in 2030. Furthermore, the COVID-​19 pandemic exacerbated world hunger in 2020 (Figures 12.3 and 12.4a,b). In 2020, nearly 10% of the world’s population suffered hunger (Figure 12.3 –​ dashed line), representing ~ 770 million people on the planet (Figure 12.4), where Africa reported the world’s highest PoU prevalence of 21%, whereas other regions were less than 10% in 2020 (Figure 12.3). The number of people undernourished by region showed an alarming increment of 12% in Africa and 1% for Latin America, and a decline from 12% for Asia (Figure 12.4a). In 2020, 12% of the world’s population (928 M) was exposed to severe food insecurity (FIES) and 18.5% (1.4 MM) to moderate food insecurity (Figure 12.5). Severe and moderate food insecurity were the highest in Africa, followed by Latin

Aquaculture and food security  205

Figure 12.4 (A, B) Number of people undernourished by region. Values for 2020 are projections. Top: Historical number of people undernourished by region (2000–​2020). Bottom: Number of people undernourished by region for 2020; n.r. =​not reported, since the prevalence is less than 2.5%. Source: FAO (2021c).

America and Asia (Figures 12.5 and 12.6). Furthermore, a gender gap showed a prevalence of moderate and severe food insecurity levels, which revealed an average difference of 10% higher among women than men with accentuated differences in Latin America and the Caribbean (Figure 12.5). Food insecurity levels have increased globally from 2014 to 2020, except for Northern America and Europe, reporting a decrease of 1%. Africa showed the highest food insecurity (FIES) (Figure 12.6). Latin America and the Caribbean recorded the highest rate of change (ROC) in moderate food insecurity, with an increment of 9.5% compared

206  Fernando Aranceta Garza

Figure 12.5 Food insecurity levels by region and gender. Source: FAO et al. (2021).

Figure 12.6 Food insecurity levels based on the Food Insecurity Experience Scale by region. Source: FAO (2021c).

Aquaculture and food security  207 to Africa and Asia (~4.2%). In the case of severe food insecurity, Africa showed the highest ROC from 2014 to 2020 (8.2%), followed by Latin America and the Caribbean (6.5%). Malnutrition also remained a challenge for reaching the 2030 nutrition and SDG goals. In 2020, 22.0% (149.2 M) of children under five years of age were affected by stunting; 6.7% (45.4 M) were suffering from wasting; and 5.7% (38.9 M) were overweight, with a potential increase due to the COVID-​19 pandemic. Most of these children live in Africa and Asia (9/​10). Anaemia (caused by micronutrient deficiency in adult women) revealed severe geographic differences: 30% of women in Africa and Asia had anaemia compared to 14% in Northern America and Europe. Moreover, adult obesity is increasing worldwide, with the highest levels observed in Northern America (35.5%), Western Asia (30%), Australia, and New Zealand (29). Latin America and the Caribbean, and Oceania (excluding Australia and New Zealand) showed levels above 20%.7 12.3  Aquaculture’s role in food security 12.3.1  The aquatic food system

Aquatic food systems include all animals and plants (algae) reared or harvested from water, including synthetic substitutes. A food system is defined as a system encompassing the entire range of actors and their interlinked value-​ added activities involved in the production, aggregation, processing, distribution, consumption, and disposal of food products. They comprise all food products that originate from crop and livestock, forestry, fisheries, and aquaculture production, as well as the broader economic, societal, and natural environments in which these diverse production systems are embedded. A sustainable food system is “a food system that delivers food security and nutrition for all in such a way that the economic, social and environmental bases to generate food security and nutrition for future generations are not compromised”.8 An aquatic food system represents a complex network of all the interrelated elements and activities of aquatic foods, including their interactions with other food systems. These elements are interlinked in continuous adaptive growth, restructuring, and renewal cycles. According to Figure 12.7, the conceptual framework of an aquatic food system has five driver categories impacting the food system, which affect three fundamental elements within, the system supporting food production, supply chains, and consumer behaviour. This last element is related to affordability/​accessibility to healthy diets that determine the nutritional and health status of the consumer with economic and social consequences to the food system. Finally, the food system can be regulated by policy actions, programmes, and institutions that can cope with meeting national or global goals, such as the Sustainable Development Goals.

newgenrtpdf

208  Fernando Aranceta Garza

Figure 12.7 Conceptual framework of food systems for diets and nutrition. Sources: HLPE (2020) and FAO et al. (2021).

Aquaculture and food security  209 The aquatic food system comprises aquaculture and fisheries production (i.e., aquatic food). The social importance of aquatic food varies on different geographical scales, parallel with the production methods. Aquatic food plays a fundamental role in the daily nutrition of many population groups or simply enriches a healthy and diverse diet with essential nutrients. The motivations for its production, fishing, or farming range from meeting the most basic food needs (hunger alleviation) to generating huge profits for multinational companies in export markets. 12.3.2  Drivers affecting aquaculture and food security trends

Table 12.2 includes the drivers affecting aquaculture production and their relationship to food security (see Figure 12.7). Demographic drivers encompass population growth issues and the mechanisms to maintain food security. Environmental drivers generally impact aquaculture’s extensive and semi-​ intensive yields. Economic drivers impact aquatic food systems (including markets and supply chains) and food security. Prices are affected and consumers’ accessibility to food is altered, presented as an economic downturn (or economic recession), economic shock (unexpected events, such as COVID-​19), or economic slowdown (i.e., economic growth at declining rates), as a direct consequence of declining wages and household income or unemployment. The political climate is important because internal conflicts and wars can disrupt food systems and supply chains from production to consumption. Direct impacts can include destroying production assets and trade disruption by negatively affecting food availability and prices. Finally, technology and innovation affect aquaculture by intensifying production and reducing environmental externalities. Poverty and inequality exacerbate these major drivers, ultimately affecting access to healthy foods, food security, and higher nutrition outcomes. Food systems can be transformed to address these major drivers to confront food insecurity, malnutrition, and the unaffordability of healthy diets. Six pathways have been recommended: (1) integrating humanitarian development and peacebuilding policies in conflict-​affected areas; (2) scaling-​up climate resilience across food systems; (3) strengthening the resilience of the most vulnerable to economic adversity; (4) intervening along the food supply chains to lower the cost of nutritious foods; (5) tackling poverty and structural inequalities, ensuring interventions are pro-​poor and inclusive; and (6) strengthening food environments and changing consumer behaviour to promote dietary patterns positively impacting human health and the environment. 12.4  Global aquatic production status The fisheries and aquaculture sectors are contributing significantly to global food security and nutrition, especially in developing and low-​income food-​deficit regions, while also supporting the livelihoods of millions of people around the globe. Global production (Figure 12.8) from marine (~87%) and inland (~13%) fisheries totals 96.4 MT. The 2018 aquaculture production was 82.1 MT, of which

newgenrtpdf

Driver

Effects on aquaculture production

Impact on food security

Demographic

Continuous human growth rate National strategies to maximise efficiency, minimise waste, and reduce fish-​ based meals and fish oil to cope with human growth Heterogeneous climate change impact among culture systems and species Acidification and hypoxia in extensive culture systems of molluscs and marine sea cages for farmed fish Extreme climate events Increased availability of farm animals –​limitation of prices on the rise and increase in their accessibility Pandemic (COVID-​19) economic downturn High-​income inequalities Low productivity and inefficient food supply chain Increased availability of aquatic (farmed) food limitation in price increase and augment accessibility National and international conflicts Low institutional capabilities Technologies for cultivation system intensification Elite access to resources that negatively affect the access and entitlement of the poor Seed shortage in developing countries Increased risk of disease and escape Environmental degradation and habitat loss

(–​) (+​)

Bio-​physical and environmental

Economic and market

Political and institutional Technology and Innovation

(+​) and (–​) (–​) (–​) (+​) (–​) (–​) (–​) (+​) (+​) (–​) (+​) (–​) (–​) (–​) (–​)

210  Fernando Aranceta Garza

Table 12.2 Effects on aquaculture production and impact on food security of major drivers

Aquaculture and food security  211 inland production represented 62% and coastal-​marine production 38%. In the case of fisheries, their production has stabilised since the 1990s (Figure 12.8). In 2017, the stock fishery status worldwide reported that 59.6% were biologically sustainable, 6.2% underfished, and 34.2% biologically unsustainable. Given current management objectives, fishing technologies, and management approaches, it is unlikely that wild catches will increase substantially without jeopardising resource sustainability, economic performance, and biodiversity conservation agreements (Jennings et al., 2016). The potential strategies to increase wild fishery yields for human consumption are increasing management policies, decreasing waste in production, processing, and the supply chain, and reducing the use of fishmeal (i.e., small pelagic) for farming purposes. In this manner, while fish production remains stagnant, aquaculture production has exceeded wild-​caught species, such as freshwater aquaculture species, diadromous, and molluscs since the 1990s and for crustacean production since the 2000s (Figure 12.9). Additionally, aquaculture is showing a potential role in food security by surpassing fish production, with a growth rate of 7.5% per year since 1970, accounting for 50% of all fish for human consumption and 43% of the total seafood supply.9 The aquatic plants, including macroalgae or seaweeds, showed almost exclusively aquaculture production globally (Figure 12.9). In 2019, aquatic plant production reached a global maximum of 40 MT, being only surpassed by the production of freshwater and marine fish (Figure 12.9). This global production reflects the potential importance of macroalgae in food security worldwide.

Figure 12.8 World capture fisheries and aquaculture production. Source: FAO (2022).15

212  Fernando Aranceta Garza

Figure 12.9 World fisheries production by capture and aquaculture (AQ), by ISSCAAP divisions (1950–​2019).

In 2019, the top 10 aquaculture producers (excluding aquatic plants and non-​ food products) were China (48.2 MT), India (7.8 MT), Indonesia (6.0 MT), Viet Nam (4.4 MMT), Bangladesh (2.5 MT), Egypt (1.6 MT), Norway (1.5 MT), Chile (1.4 MT), Myanmar (1.1 MT), and Thailand (1 MT), with a total production of 75.4 MT (relative to 88.4% of total aquaculture production).

Aquaculture and food security  213

Figure 12.10 World aquaculture production by ISSCAAP divisions. Total aquaculture production was 85.3 million tons (MT). Source: FAO (2021a).16

In 2019, aquaculture production by species groups showed the importance of finfish, with a 66% contribution to total production, of which 55% were freshwater fishes. The next species group was mollusc with 20.6%, crustaceans with 2.3%, and 1.1% of other aquatic animal species (Figure 12.10). 12.5  General contribution of aquatic food to food security Aquaculture plays an increasing role in aquatic food security worldwide. Recent studies10 have shown a positive relationship between aquaculture production and the country’s domestic aquatic food consumption. In the long term, as global production increases, the cost decreases, resulting in greater accessibility. Moreover, since domestic aquaculture has expanded, the consumption of aquatic food among people experiencing poverty has increased. Aquatic food system production (both wild-​caught and farmed production) represents the most significant and cheapest source of proteins (35%) in comparison to other meat sources, such as poultry (23%) and pigs (21%), and even higher than cattle (13%) (Figure 12.11), from which total animal protein production represents 514 MT for 2019 (Figure 12.11). Consumption of fish protein is regionally heterogeneous and driven by cultural, economic, and self-​choice factors. In 2017, global fish consumption was 20.3 kg/​year per capita, whereas Oceania (25 kg/​year), Asia (24.1 kg/​year), Northern America (22.4 kg/​year), and Europe (21.4 kg/​year) were beyond the global per capita

214  Fernando Aranceta Garza

Figure 12.11 World production of meat including fish and seafood meat from 2000 to 2019. Source: FAOSTAT (2021).17

consumption of fish, representing 75% of the world’s population (Figure 12.12 –​ top). Below the global average, fish consumption was 10.5 kg/​year and 9.9 kg/​year per capita for Latin America (and the Caribbean) and African regions. Economic grouping of countries (Figure 12.11 –​bottom) showed that fish consumption was highest in industrialised/​developed countries, with 24–​27 kg/​year per capita, followed by developing countries with 20.7 kg/​year per capita. Below this global average, per capita consumption was minimum for least developed countries (12.3 kg/​year) and low-​income food-​deficit countries (9.3 kg/​year). Moreover, fish contribution to animal protein supply showed relatively higher ratios in developing countries (i.e., least developed countries, developing countries, and low-​income food-​deficit countries, ranging from 19% to 30% of fish share) than in developed countries (12% of fish share) (Figure 12.13 –​ bottom). This pattern shows that aquatic food can have a pivotal role in daily nutrition (or food security) for some regions and can provide variety and some essential nutrients in already ample diets. In 2017, 55 countries were the world’s major fish consumers, with 19% or above of fish share to total proteins, representing 43% of the world’s population (Figure 12.14 –​top), where 78% were from developing countries, 15% from least developed countries, and 7% from developed countries. The per capita fish consumption for these countries was 61 kg/​year for developed countries, 37 kg/​year in developing countries, 26 kg/​year for least developed countries, and 17.8 kg/​year for low-​income food-​deficit countries (Figure 12.14 –​ top). Fish contribution to total proteins showed a similar tendency in fish consumption per capita (Figure 12.13 –​ bottom), and all the categories were beyond the global average of 6.8%.

Aquaculture and food security  215

Figure 12.12 Fish consumption per capita by continent and economic groups. Dotted lines represent the world’s average fish consumption at 20.3 kg/​year per capita. Source: FAO (2021a).

Fish share to total animal proteins showed an inverse tendency, where consumers recorded a higher share in less developed countries (42.2%) followed by low-​income food-​deficit countries (38.2%), other developing countries (29.6 %), and developed countries (26.5%) (Figure 12.14 –​middle). Preliminary estimates for 2019 showed an increase in per capita consumption to about 20.5 kg, with the share of aquaculture production in total available food fish supply surpassing capture fisheries (11.1 kg vs. 9.5 kg).

216  Fernando Aranceta Garza

Figure 12.13 Fish protein contribution to animal or total proteins consumed daily per capita by continent and economic grouping. Source: FAO (2021a).

In the case of seaweed production, they are a rich source of minerals, fibres, polyunsaturated fatty acids, polysaccharides, bioactive compounds, and vitamins, whose proportions vary among species and are very nutritious for the human diet. Hence the ecological benefits of seaweed farming (CO2 sink, wave energy absorption, pH increment, water oxygenation, and alleviation of agriculture’s environmental footprint), and the inclusion of seaweeds in diets is increasing. Seaweed serves as a source of

Aquaculture and food security  217

Figure 12.14 Fish consumption per capita (a); fish share over animal proteins (b); and fish share over total proteins (c) for the top 55 countries ranked by fish contribution to animal protein supply above 19%. Source: FAO (2021a).

218  Fernando Aranceta Garza food in Asian-​Pacific islands and is entering Western cultures, mainly in a variety of presentations, e.g., dried and fried, and as an agent for flavour or a texture enhancer on a variety of foods. Expanding seaweed farming to developing countries could help reduce local poverty, improve ecosystem management, and aid climate change mitigation, aiming to produce valuable biomass for other wealthy countries with no new land or water usage.11 However, the main challenges of making seaweed a common diet for millions of people resides in making seaweed products accessible, affordable, nutritionally balanced, and attractive to consumers. 12.6  Nutritional value of fish for human health Fish is one of the most nutritious foods containing macro-​and micronutrients, and is still an under-​recognised and undervalued source of micronutrients that can play a significant role in global food safety.12 Small pelagic fish, e.g., herring, sardine, and anchovy, supply abundant nutrition to low-​and middle-​income countries, representing the cheapest animal protein in a daily diet for most of these countries. In nutrient-​deficient countries,