SlideShare a Scribd company logo
Aquaculture Toxicology
AQUACULTURE
TOXICOLOGY
This page intentionally left blank
AQUACULTURE
TOXICOLOGY
Edited by
FREDERICK S.B. KIBENGE
Department of Pathology and Microbiology, Atlantic
Veterinary College, University of Prince Edward Island,
Charlottetown, PE, Canada
BERNARDO BALDISSEROTTO
Full Professor, Department of Physiology and
Pharmacology, Federal University of Santa Maria,
Santa Maria, Rio Grande do Sul, Brazil
ROGER SIE-MAEN CHONG
Registered Veterinary Specialist of Fish Health and
Production, Royal College of Veterinary Surgeons, London,
United Kingdom
Registered Specialist of Veterinary Aquatic Animal Health,
Queensland Veterinary Surgeons Board; Senior Veterinarian
(Aquatic Pathology) Biosecurity Sciences Laboratory, QLD,
Australia
Current affiliation: Australian Commonwealth Scientific
Industrial Research Organization (CSIRO), Brisbane, QLD,
Australia
Academic Press is an imprint of Elsevier
125 London Wall, London EC2Y 5AS, United Kingdom
525 B Street, Suite 1650, San Diego, CA 92101, United States
50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States
The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom
© 2021 Elsevier Inc. All rights reserved.
No part of this publication may be reproduced or transmitted in any form or by any means, electronic
or mechanical, including photocopying, recording, or any information storage and retrieval system,
without permission in writing from the publisher. Details on how to seek permission, further
information about the Publisher’s permissions policies and our arrangements with organizations such
as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website:
www.elsevier.com/permissions.
This book and the individual contributions contained in it are protected under copyright by the
Publisher (other than as may be noted herein).
Notices
Knowledge and best practice in this field are constantly changing. As new research and experience
broaden our understanding, changes in research methods, professional practices, or medical
treatment may become necessary.
Practitioners and researchers must always rely on their own experience and knowledge in evaluating
and using any information, methods, compounds, or experiments described herein. In using such
information or methods they should be mindful of their own safety and the safety of others, including
parties for whom they have a professional responsibility.
To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume
any liability for any injury and/or damage to persons or property as a matter of products liability,
negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas
contained in the material herein.
Library of Congress Cataloging-in-Publication Data
A catalog record for this book is available from the Library of Congress
British Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library
ISBN 978-0-12-821337-7
For information on all Academic Press publications
visit our website at https://www.elsevier.com/books-and-journals
Publisher: Mica Haley
Acquisitions Editor: Patricia Osborn
Editorial Project Manager: Billie Jean Fernandez
Production Project Manager: Maria Bernard
Cover Designer: Greg Harris
Typeset by SPi Global, India
Contents
Contributors ix
About the editors xi
Preface xiii
1. Introduction to aquaculture 1
Frederick S.B. Kibenge
1.1 Introduction 1
1.2 Structure of the global aquaculture industry 2
1.3 Mollusk aquaculture 9
1.4 Crustacean aquaculture 10
1.5 Chemicals in aquaculture 10
1.6 Governance of aquaculture 11
References 12
2. General introduction to toxicology of aquatic animals 17
Bernardo Baldisserotto
2.1 Introduction to toxicology 17
2.2 Water quality criteria/guidelines 18
2.3 Intraspecies variation of toxicity 20
2.4 Models to predict toxicity of contaminants 21
References 22
3. Antifoulants and disinfectants 25
Samantha Eslava Martins and Camila de Martinez Gaspar Martins
3.1 Overview 25
3.2 Definitions and uses 26
3.3 Mode of action 28
3.4 Ecotoxicity and biological effects 33
3.5 Ecological risks and regulation 46
3.6 Further considerations 49
References 50
v
4. Metals 59
Claudia B.R. Martinez, Juliana D. Simonato Rocha, and Paulo Cesar Meletti
4.1 Introduction 59
4.2 Biochemical effects 62
4.3 Physiological effects 67
4.4 Behavioral effects 69
References 73
5. Agrochemicals: Ecotoxicology and management
in aquaculture 79
Vania Lucia Loro and Bárbara Estevão Clasen
5.1 Water and soil contamination by agrochemicals 79
5.2 Environmental contamination by agrochemicals and risk assessment
in aquaculture: Effects on aquatic organisms and food for human
consumption 82
5.3 Mitigation of agrochemicals 94
5.4 Agrochemicals banned from use in agriculture and aquaculture 98
5.5 Regulatory process for new chemicals and good agricultural
practices 98
References 101
6. Pharmaceutical pollutants 107
Helena Cristina Silva de Assis
6.1 Introduction 107
6.2 Pharmaceuticals in the aquatic environment 108
6.3 Pharmaceutical sources and pathway to the environment 109
6.4 Pharmaceutical exposure effects in nontarget species 111
6.5 Final considerations 123
References 124
7. Oil and derivatives 133
Helen Sadauskas-Henrique, Luciana Rodrigues Souza-Bastos, and
Grazyelle Sebrenski Silva
7.1 Oil and derivatives and the aquatic contamination 133
7.2 Aquaculture and the problem of oil and derivative
contamination 137
vi Contents
7.3 Effects of oil and derivatives on fish species 140
7.4 Effects of oil and derivatives on mollusks and crustaceans 160
7.5 Interaction of oil and derivatives with water characteristics 169
7.6 Future perspectives on oil and derivative contamination and
aquaculture 172
References 173
8. Ecotoxicological effects of microplastics and associated
pollutants 189
Fábio Vieira de Araújo, Rebeca Oliveira Castro, Melanie Lopes da Silva,
and Mariana Muniz Silva
8.1 Introduction 189
8.2 Impacts of microplastic on marine animals 190
8.3 Plastic additives 191
8.4 Microplastic and persistent organic pollutants (POPs) 195
8.5 Microplastics and metals 203
8.6 Microplastics and microorganisms: The plastisphere 205
8.7 Microplastics and other compounds 213
8.8 Final considerations 214
References 216
Index 229
vii
Contents
This page intentionally left blank
Contributors
Bernardo Baldisserotto
Department of Physiology and Pharmacology, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
Bárbara Estevão Clasen
Department of Environmental Sciences, State University of Rio Grande do Sul, Tr^
es Passos, RS, Brazil
Rebeca Oliveira Castro
Programa de Pós Graduação em Biologia Marinha e Ambientes Costeiros, Universidade Federal Fluminense,
Niterói, RJ, Brazil
Camila de Martinez Gaspar Martins
Universidade Federal do Rio Grande—FURG, Instituto de Ci^
encias Biológicas, Rio Grande/RS, Brazil
Fábio Vieira de Araújo
Faculdade de Formação de Professores, Universidade do Estado do Rio de Janeiro, São Gonçalo, RJ, Brazil
Grazyelle Sebrenski Silva
Departamento de Morfologia, Universidade Federal do Amazonas (UFAM), Manaus, Brazil
Luciana Rodrigues Souza-Bastos
Instituto de Tecnologia para o Desenvolvimento (LACTEC), Laboratório de Toxicologia e Avaliação
Ambiental, Ambiental, Curitiba, Brazil
Mariana Muniz Silva
Programa de Pós Graduação em Biologia Marinha e Ambientes Costeiros, Universidade Federal Fluminense,
Niterói, RJ, Brazil
Melanie Lopes da Silva
Laboratório de Ecologia e Din^
amica B^
entica Marinha, Faculdade de Formação de Professores, Universidade do
Estado do Rio de Janeiro, São Gonçalo, RJ, Brazil
Frederick S.B. Kibenge
Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island,
Charlottetown, PE, Canada
Vania Lucia Loro
Laboratory of Aquatic Toxicology, Department of Biochemistry and Molecular Biology, Federal University of
Santa Maria (UFSM), Santa Maria, RS, Brazil
Paulo Cesar Meletti
Laboratory of Animal Ecophysiology, Department of Physiological Sciences, State University of Londrina,
Londrina, Parana, Brazil
Claudia B.R. Martinez
Laboratory of Animal Ecophysiology, Department of Physiological Sciences, State University of Londrina,
Londrina, Parana, Brazil
Samantha Eslava Martins
Norwegian Institute for Water Research (NIVA), Ecotoxicology and Risk Assessment Section, Oslo, Norway;
Universidade Federal do Rio Grande—FURG, Instituto de Ci^
encias Biológicas, Rio Grande/RS, Brazil
Helena Cristina Silva de Assis
Department of Pharmacology, Federal University of Paraná, Curitiba, Paraná, Brazil
ix
Helen Sadauskas-Henrique
Universidade Santa Cecı́lia (Unisanta), Laboratório de Biologia de Organismos Marinhos e Costeiros
(LABOMAC), Santos, Brazil
Juliana D. Simonato Rocha
Laboratory of Animal Ecophysiology, Department of Physiological Sciences, State University of Londrina,
Londrina, Parana, Brazil
x Contributors
About the editors
Dr. Frederick S.B. Kibenge is Professor of Virology at the Atlantic Vet-
erinary College, University of Prince Edward Island, Charlottetown, PEI,
Canada, where he has been Chairman of the Department of Pathology
and Microbiology for several years, and teaches veterinary virology in
the second year of the DVM curriculum. He has been working with
animal viruses for more than 30years in addition to prior extensive postdoc-
toral research experience in virology in the United Kingdom and the United
States. He is a Diplomate of the American College of Veterinary Microbiol-
ogists, ACVM (subspecialty Immunology). He has published extensively on
the detection and virology of fish viruses. He is editor of the accompanying
two textbooks on the theme of aquaculture: Aquaculture Pathophysiology and
Aquaculture Pharmacology published by Elsevier Inc., Academic Press.
Dr. Bernardo Baldisserotto is a full Professor of Physiology of the
Departamento de Fisiologia e Farmacologia at the Universidade Federal
de Santa Maria, in South Brazil. He supervises graduate students from the
programs of Animal Husbandry, Pharmacology, and Animal Biodiversity
at this university and has published several articles dealing with toxicology
of aquatic animals, mainly fish. He is the coauthor on some of the book
chapters and has published a book regarding Pharmacology applied to aqua-
culture (in Portuguese). He is editor of the accompanying two textbooks on
the theme of aquaculture: Aquaculture Pathophysiology and Aquaculture Phar-
macology published by Elsevier Inc., Academic Press.
Dr. Roger Sie-Maen Chong is a veterinary specialist in Australia and
the United Kingdom, with expertise in fish and shellfish pathology as applied
to the health and biosecurity of aquacultured species. He is officially regis-
tered as a specialist by the Queensland Board of Veterinary Surgeons for
Veterinary Aquatic Animal Health (Australia) and by the Royal College
of Veterinary Surgeons for Fish Health and Production (United Kingdom).
He is also a certified fish pathologist recognized by the Fish Health Section of
the American Fisheries Society. He has worked in Hong Kong with the
Department of Agriculture, Fisheries & Conservation, in Queensland with
the Biosecurity Queensland and is presently a research fish pathologist with
the Australian Commonwealth Scientific and Industrial Research
Organization (CSIRO). He is editor of the accompanying two textbooks
on the theme of aquaculture: Aquaculture Pathophysiology and Aquaculture
Pharmacology published by Elsevier Inc., Academic Press.
xi
This page intentionally left blank
Preface
The textbook Aquaculture Toxicology focuses on the practical principles of
toxicology of finfish (mainly), crustaceans, and mollusks, the three major
groups of aquatic animal species cultured for human consumption.
Recent books on this subject have a more general approach on aquatic tox-
icology, focusing more in chemical aspects of toxicology and pollutants
(Introduction to Aquatic Toxicology by Nikinmaa, M., Elsevier, 2014;
Microscale Testing in Aquatic Toxicology by Wells et al., CRC Press,
2018) or the specific aspects of the effects of pollutants (Aquatic Toxicology:
Molecular, Biochemical, and Cellular Perspectives by Malins D.C. and
Ostrander, G.K., 2018). Aquaculture is a rapidly growing agricultural sector
and requires updated research information on general aspects of several types
of toxicants to control or avoid their negative impacts on the culture of
aquatic animals.
The book is multiauthored and edited. All contributing authors for the
different chapters are highly respected international experts recognized in
their specific areas, who have published several articles dealing with the sub-
ject of their respective chapters; some have also written book chapters on the
subject. Each book chapter has been written from the perspective of the
expert, providing the reader with nuances of the topic without compromis-
ing on the essential and useful facts or being encyclopedic but reflecting
global research. Aquaculture Toxicology presents an overview of the practical
information on the effects and sources of most common pollutants: disinfec-
tants and antifoulants, metals, agrochemicals, pharmaceuticals, oils and
derivatives, and microplastics. The authors were encouraged to use the
same format in all chapters to facilitate ease of reading and studying, and
to maintain consistency throughout the book although the ultimate
approach chosen by different authors is reflective of the state of knowledge
on the respective topics. A list of subtitles is included at the beginning of each
chapter to provide the reader with a quick summary of what is covered in
each chapter.
This book provides the target audience with a reliable and valuable up-
to-date, “all-inclusive” reference and guide to the state of the field, serving as
a systematic and concise resource for aquaculture specialists/researchers
interested in toxicity of various agents to fish, crustaceans, and mollusks,
and particularly researchers, clinical veterinarians, and possibly government
xiii
personnel interested in aquaculture, the fisheries and comparative biology,
and how treatments may affect the aquatic animals directly. It is hoped that
having such a comprehensive easily readable book focused on aquaculture
will identify areas where more research is needed to generate more knowl-
edge to support a sustainable aquaculture industry.
The editors acknowledge the authors for their contributions.
Frederick S.B. Kibenge
Bernardo Baldisserotto
Roger Sie-Maen Chong
EDITORS
xiv Preface
CHAPTER ONE
Introduction to aquaculture
Frederick S.B. Kibenge
Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island,
Charlottetown, PE, Canada
1.1 Introduction
The Food and Agricultural Organization of the United Nations
(FAO) attributes aquatic organisms that are harvested by an individual or
corporate body which has owned them throughout their rearing period
to aquaculture. In contrast, aquatic organisms that are exploitable by the
public as a common property resource, with or without appropriate licenses,
are the harvest of fisheries (FAO, 2015). Two critical criteria of human activ-
ity, ownership of stock and deliberate intervention in the production cycle,
distinguish aquaculture from capture fisheries and also account for the envi-
ronmental concern centered on water quality/water pollution that consti-
tutes Aquaculture Toxicology. It has been noted that the environmental
impacts of aquaculture vary with species, system, management, production
intensity, location, and environmental carrying capacity to absorb impacts
(FAO, 2016). For example, the intensive rearing of fish has led to an increase
in water pollution per unit of farmed fish produced (Hall et al., 2011). On
the contrary, the filter feeding finfish typically raised in inland multispecies
aquaculture systems (mostly silver carp Hypophthalmichthys molitrix and big-
head carp H. nobilis, and most recently Mississippi paddlefish Polyodon
spathula) and marine bivalve mollusks (oysters, mussels, clams, and scallops)
raised in seas, lagoons, and coastal ponds require no artificial feeding (FAO,
2018) and improve the water quality in the production system by removing
waste materials, including waste from fed aquatic animal species, and low-
ering the nutrient load (FAO, 2018; Hishamunda et al., 2014; Parisi et al.,
2012). Deep-sea aquaculture is associated with a lower environmental
impact on the seafloor (Welch et al., 2019) because of deeper waters and
stronger ocean currents that disperse organic matter from farms, in contrast
to nearshore farming.
This introductory chapter describes the structure of the global aquacul-
ture industry (finfish, mollusks, crustaceans, in cold water and warm water,
Aquaculture Toxicology © 2021 Elsevier Inc.
https://doi.org/10.1016/B978-0-12-821337-7.00007-4 All rights reserved.
1
commercial and noncommercial, and small and big operations) and its
importance in supplying animal protein food to the growing human popu-
lation. A better understanding of the aquaculture methods will allow the
reader to recognize the full implications of the toxic effects associated with
different aquaculture environments and help improve toxicological risk
management for aquaculture. The chapters that follow provide an overview
of practical information covering five main aspects of Aquaculture Toxicology
in the three main aquaculture groups (fish, crustaceans, and mollusks): (1)
water quality criteria/guidelines used internationally and models used to
predict the toxicity of contaminants; (2) the primary disinfectants and
organic antifouling co-biocides currently used in aquaculture, pharmaceu-
ticals used in human and veterinary medicine and their by-products that
enter the aquatic environment; (3) water pollutants such as metals, oils
and their derivatives, and microplastics that are toxic to aquatic animals
but arising from nonaquaculture sources; (4) mechanisms of toxicity and
the responses to toxic agents including aspects of uptake, metabolism, and
excretion of toxicants in fish, crustaceans, and mollusks, and toxic effects
on nontarget aquatic organisms; and (5) brief overviews of the current
regulatory aspects of the use of these products.
1.2 Structure of the global aquaculture industry
The contribution of wild-catch fisheries as an animal protein source
for human consumption plateaued in the mid-1980s, and since then, most
natural stocks in marine waters have been harvested at, or near-maximum
rates, with the quantity of fish produced by capture fisheries, projected to
increase at only 0.2% per year for the period 2019–2028 (OECD/FAO,
2019). In contrast, the average growth in the aquaculture sector in the same
period is projected at 2.0% per year (OECD/FAO, 2019). Since 2015,
aquaculture has overtaken capture fisheries as the source of seafood for
human consumption, as global fisheries have remained flat and will continue
to be flat for the foreseeable future (OECD/FAO, 2019). This share of
aquaculture is projected to rise to 62% by 2030 as catches from wild capture
fisheries level off (FAO, 2014; World Bank, 2013). Fish, mollusks, and
crustaceans represent the most economically important global aquaculture
industry subsectors (Fig. 1.1), at 80.04 million tonnes in 2016 with an
estimated total farm gate value of USD 154.2 billion (FAO, 2018), and
expected to reach USD 202.96 billion by 2020 (Grand View Research
Inc., 2014).
2 Frederick S.B. Kibenge
Most of the global aquaculture production (89% by volume) is located in
countries in Asia (most notable being China, Indonesia, India, Vietnam,
South Korea, and the Philippines; production involves mostly freshwater
species, i.e., inland aquaculture). In terms of marine aquaculture, Norway’s
Atlantic salmon industry makes it the world’s largest marine aquaculture
producer, although this accounts for just 3% of total world farmed finfish
output (Cooke, 2016). Another top aquaculture producer is Egypt, whose
tilapia and shrimp farming have exponentially increased in the last two
decades, and by 2017 at approximately 1.3 million metric tons, surpassed
total production by Norway (1.19 million metric tons) and Chile
(1.11 million metric tons) (Tran, 2019).
1.2.1 Aquatic animal species in aquaculture
Among the three main aquaculture groups (fish, crustaceans, and mollusks),
there were 369 finfishes (including five hybrids), 109 mollusks, and 64 crus-
taceans species recorded by FAO as cultured in 2016 (FAO, 2018). Carp
dominates production in both China and the rest of Asia; for Europe and
South America, it is salmonids; African aquaculture production is almost
exclusively tilapias; for Oceania, shrimps and prawns dominate (Hall
et al., 2011). In the USA, catfish predominate (Cooke, 2016). The most
important farmed species (with a production of 1% or more of the total
in 2016) (FAO, 2018) are listed in Table 1.1. However, the analysis of aqua-
culture production and details about farmed species remain approximations
because many indigenous aquatic species are used in aquaculture without
(A) (B)
21%
10%
68%
1%
Mollusks
Crustaceans
Fish
Other species
11%
24%
62%
3%
Mollusks
Crustaceans
Fish
Other species
Fig. 1.1 World aquaculture by farmed species sector. (A) Aquaculture industry subsec-
tors by quantity 2016 and (B) aquaculture industry subsectors by value 2016. Adapted
from FAO, 2018. Leading species in global aquaculture production in 2016 (in million
metric tons). Statista. Statista Inc. https://www.statista.com/statistics/240268/top-global-
aquaculture-producing-countries-2010/ Accessed: July 14, 2019.
3
Introduction to aquaculture
Table 1.1 Major farmed species in world aquaculture.
Aquaculture
sector Species or species groupsa
% of total,
2016
Finfish
Grass carp (Ctenopharyngodon idellus) (FW) 11
Silver carp (Hypophthalmichthys molitrix) (FW) 10
Tilapias (Oreochromis niloticus)  other cichlids (FW) 10
Common carp (Cyprinus carpio) (FW) 8
Bighead carp (Hypophthalmichthys nobilis) (FW) 7
Crucian carp (Carassius carassius) (FW) 6
Major (Indian) carp (Catla catla) (FW) 6
Freshwater fishes nei, Osteichthyes (FW) 4
Atlantic salmon (Salmo salar) (D) 4
Roho labeo (Labeo rohita) (FW) 3
Pangas catfishes (Pangasius spp.) (FW) 3
Milkfish (Chanos chanos) (D) 2
Torpedo-shaped catfishes nei (Clarias spp.) 2
Marine fishes nei (Osteichthyes) (M) 2
Wuchang bream (Megalobrama amblycephala) (FW) 2
Rainbow trout (Oncorhynchus mykiss) (D) 1
Cyprinids (Cyprinidae) (FW) 1
Black carp or black Chinese roach (Mylopharyngodon
piceus) (FW)
1
Northern snakehead (Channa argus) (FW) 1
Other finfishes 16
Finfish total 100
Crustaceans
White leg shrimp (Litopenaeus vannamei, formerly
Penaeus vannamei)
53
Red swamp crawfish (Procambarus clarkii) 12
Chinese mitten crab (Eriocheir sinensis) 10
Giant tiger prawn or Asian tiger shrimp (Penaeus
monodon)
9
Oriental river prawn (Macrobrachium nipponense) 4
Giant river prawn (Macrobrachium rosenbergii) 3
Other crustaceans 9
Crustaceans
total
100
Mollusks
Cupped oysters nei (Crassostrea spp.) 28
Japanese carpet shell or Manila clam (Ruditapes
philippinarum)
25
Scallops (Pectinidae) 11
4 Frederick S.B. Kibenge
being registered individually in national statistics. Numerous single species
registered in the official statistics of many countries consist, in reality, of
multiple species and sometimes hybrids (i.e., the number of finfish hybrids
in commercial production is more than five) (FAO, 2018). In China, more
than 200 species are farmed commercially, but the total production is
registered under fewer than 90 species and species groups.
Similarly, in India and Vietnam, the number of cultured species far
exceeds the number included in statistics (FAO, 2014). Moreover, for the
most widely farmed species, tilapia, the correct number of producer coun-
tries is higher than the FAO record of 135 countries because commercially
farmed tilapias are not yet reflected separately in national statistics in Canada
and some European countries (FAO, 2014). In terms of the projected
increase in aquaculture production, by 2028, carp and mollusks are projected
to remain the most significant aquaculture groups, accounting for 35.8% and
19.2%, respectively, of total production (OECD/FAO, 2019).
1.2.2 Aquaculture techniques, systems, and facilities
The techniques, systems, and facilities used in aquaculture are as diverse as
the species currently being raised and also vary by geographical region
(Bostock et al., 2010), but typically encompass three stages: incubation/
hatchery seed production, early-rearing, and on-growing (Roberts and
Shepherd, 1974). In salmon and trout aquaculture, on-growing has merged
with husbandry and breeding (Aarset and Borgen, 2015). For new farmed
Table 1.1 Major farmed species in world aquaculture—cont’d
Aquaculture
sector Species or species groups
% of total,
2016
Marine mollusks (Mollusca) 7
Sea mussels (Mytilidae) 6
Chinese razor clam or Agemaki clam or constricted
tagelus (Sinonovacula constricta)
5
Pacific oyster, Japanese oyster, or Miyagi oyster
(Crassostrea gigas)
3
Blood cockle or Blood clam (Anadara granosa) 3
Chilean mussel (Mytilus chilensis) 2
Other mollusks 10
Mollusks total 100
a
Major farmed species or species groups (with a production of 1% or more of the total in 2016) (FAO,
2018). FW, freshwater; D, diadromous (these fish spawn in freshwater and migrate to the sea for the main
growing period); M, marine.
5
Introduction to aquaculture
species like cod, mainly two methods are used: one is based on capturing
wild cod for on-growing, the other focuses on the production of cod from
hatchery seed to market size; currently, on-growing of wild cod (e.g., as in
sea ranching (Kitada, 2018)) is more economically efficient than using
farmed juveniles (Gunnarsson, 2007). For a few species, such as eels
“Anguilla spp.,” farming still relies entirely on the wild seed. Although
the Japanese eel “Anguilla japonica” life cycle in captivity has been completed,
the techniques for mass production of glass eels have not yet been established
because of various technical difficulties (Bird, 2013; Masuda et al., 2012).
A comprehensive review of the different aquaculture systems worldwide
can be found in Boyd and McNiven (2015). World aquaculture production
takes place under four main systems: (1) on land (using freshwater or saline
water) in static water ponds (e.g., for growing channel catfish and other
warm-water species), concrete raceway systems (e.g., for growing rainbow
trout), fresh water gravity tanks, or large recirculation tanks; (2) in floating
cages and net pens in a lake or river (e.g., for growing salmonids and other
cold-water species that require clean water with high oxygen levels) or on
the shoreline/nearshore in sheltered waters (mariculture or marine aquacul-
ture 3km from the shore) in floating net cages moored to the bottom in
the sea with long lines (Shepherd, 1993; White and Edwards, 2015); (3) in
coastal lagoons or brackish-water or marine ponds (e.g., for shellfish
aquaculture) (Parisi et al., 2012; Wever et al., 2015; White and Edwards,
2015); and (4) in onshore-based tanks using pumped sea water (e.g., for flat
fish farming of turbot or halibut that normally lie on the bottom and will not
shoal within the water column inside a floating cage (Shepherd, 1993)).
1.2.3 Finfish aquaculture
Seven of the top ten cultured fish species are carps; others are tilapias, Pangas
catfishes, and Atlantic salmon (Table 1.1). China, the largest producer of
farmed seafood, grows carp mostly in ponds and rice paddies, with little
or no attempt to actively nurture the animals and has been practicing this
type of aquaculture for thousands of years. Most carp farming is pond-based,
with several species stocked in the same pond (polyculture) (SPC, 2011).
Tilapia and sometimes catfish are stocked together with carp. Single-species
culture (monoculture) is rare, except in the flow-through system and cage
culture of common carp in streams or canals. There are different stocking
models for polyculture, depending on the availability of the primary source
of feed. If grasses (aquatic or terrestrial) are abundant, grass carp can be
6 Frederick S.B. Kibenge
stocked as the dominant species. The leftover feed and grass carp excreta
would sufficiently fertilize the pond water for the growth of filter feeders.
For example, the “80:20 pond fish culture” where 80% of harvest weight
comes from the pellet-fed target species (such as grass carp, crucian carp,
or tilapia) and the other 20% comes from the filter feeding “service species”
(silver carp) (White and Edwards, 2015). Pond-based carp culture has been
traditionally integrated with crop farming (rice, mulberry, fruit, and vege-
tables) and animal husbandry (ducks, swine, and chicken) in China
(White and Edwards, 2015). The practice has been widely introduced to
many other parts of the world, with some modifications to fit into local
conditions (SPC, 2011). Polyculture (the mixing of species in fish farms)
has taken a different trajectory since 2008 and is widely used in sea cages
for a different purpose in the form of using “cleaner fish” (lumpfish
Cyclopterus lumpus and wrasse (Labridae)) in marine farmed salmonids as a
biological control method for sea lice Lepeophtheirus salmonis in Europe
(Powell et al., 2018; Skiftesvik et al., 2014) and Canada; it involves the
use of wild-caught cleaner fish directly in the salmon farms or as broodstock
for hatchery-raised cleaner fish (EURLFD, 2016).
In industrial aquaculture, farmed fish are reared at high population
densities in floating open net cages nearshore (for marine aquaculture) or
in a lake or river (for inland aquaculture) (White and Edwards, 2015).
The cages are either of square/hexagonal steel platform construction that
are linked together or are of circular polyethylene rings 10–50m deep with
netting to hold in farmed fish. Expansion can simply be by increasing the
number of fish in a cage (i.e., cage volume) or by increasing the number
of cages. Formulated dry feeds supply all nutrition. Uneaten feed and feces
fall through the cages and settle to the bottom in the vicinity. Cages are
periodically moved to new locations to allow benthic communities affected
by sediment to recover—a process called fallowing (Boyd and McNiven,
2015). Current production systems operate on a single-year-class stocking
in a site, usually a bay (“All-in, all-out”) with a fallow period of 6 months
in between year classes.
Closed containment is a practice that entails enclosing fish in floating
containers or land-based farms to lessen their damage to the aquatic environ-
ment (Real, 2010). Recent improvements in offshore technology now
allow even larger floating fish cages out in the sea that are submersible with
automated feeding systems and remote monitoring. This has enabled the
expansion of aquaculture farther offshore (i.e., deep-sea aquaculture) into
high-energy sites and with a low environmental impact on the seafloor
7
Introduction to aquaculture
(Lovatelli et al., 2013; Welch et al., 2019). China currently has one of the
world’s biggest fully submerged net cage farming Atlantic salmon in the Yel-
low Sea (Owen, 2018); and SalMar’s Ocean Farm 1 is 40km off the coast of
Frohavet, Norway (Bennet, 2019). Moving fish farms out to sea helps to
solve several problems. The open ocean offers more space, deeper waters,
and stronger currents. Ocean currents are particularly effective for reducing
the spread of pathogens and allowing better exchange and dilution of wastes
than nearshore farming; greater distance offshore also minimizes interactions
with wild fish and reduces the risk of unwanted exposure of nontarget
organisms to aquacultural chemicals (Park et al., 2012).
On land, increased development of land-based recirculating aquaculture
system (RAS) (Espinal and Matuli
c, 2019) is leading to an ever-increasing
move to saltwater land-based aquaculture, particularly in Europe and most
recently in North America, despite the significant capital costs compared to
those for floating cage farms. RAS offers environmentally sustainable
methods for farming marine (Tal et al., 2009) and freshwater fish by having
minimal effluents compared to other systems (White and Edwards, 2015).
For example, in BC-Canada, a recent analysis for the Fraser Basin Council
found that a capital investment of $1.1 billion would be required to establish
a land-based industry capable of producing 50,000 tons of Atlantic salmon a
year on Vancouver Island (Shore, 2019). There is already extensive knowl-
edge derived from land-based hatcheries. The capital costs are compensated
by lower operating costs, for example, land-based aquaculture farms have
low pharmaceutical costs (e.g., no sea lice therapeutics) and no costs of
maintaining boats that go out to feed the fish (Kramer, 2015).
Moreover, with land-based farming, there would be no interactions
between farmed fish and wild fish (Shore, 2019). However, while land-
based aquaculture requires low antibiotic usage, there appears to be a con-
nection in antimicrobial resistance issues found in land-based aquaculture
with those established by terrestrial animal agriculture (Done et al., 2015).
Another crucial disadvantage has been the development of “off-flavor” of
the harvested fish “caused by geosmin and 2-methylisoborneol metabolites
released by microbes that grow within the land-based systems” (Sapin
et al., 2020).
Another aquaculture development that has gained traction in recent
years is the biofloc technology (White and Edwards, 2015). Biofloc technol-
ogy is a technique of enhancing water quality in aquaculture through the
manipulation of microbiota to convert the harmful waste from aquaculture
production to consumable body biomass, with many other benefits (Dauda,
8 Frederick S.B. Kibenge
2019). The technology has recently gained attention as a sustainable method
to maintaining optimum water quality parameters under a zero-water
exchange system, thus preventing eutrophication and effluent discharge into
the surrounding environment, thereby increasing biosecurity, as there is no
water exchange except sludge removal (Ahmad et al., 2017). The technol-
ogy has the added value of producing proteinaceous feed in situ, which
results in higher productivity with less impact on the environment
(Bossier and Ekasari, 2017). It has been considered the new “blue revolu-
tion” in aquaculture (Emerenciano et al., 2017). It may act as a complete
source of nutrition for aquatic organisms, along with some bioactive
compounds that will enhance growth, survival, and defense mechanisms
and acts as a novel approach for health management in aquaculture by
stimulating the innate immune system of animals. Beneficial microbial bac-
terial floc and its derivative compounds such as organic acids, polyhydroxy
acetate, and polyhydroxy butyrate could resist the growth of other
pathogens and thus serve as a natural probiotic and immunostimulant. This
technology is economically viable, environmentally sustainable, and socially
acceptable (Ahmad et al., 2017; Daniel and Nageswari, 2017).
1.3 Mollusk aquaculture
In the case of mollusk (oysters, clams, scallops, abalone, mussels,
cockles, and related species) aquaculture, there are many varieties of culture
and grow-out methods that are particular to species and locations (Boyd
et al., 2005; Dı́az et al., 2011; Dumbauld et al., 2009; Elston, 1999;
Elston and Ford, 2011; Parisi et al., 2012). For example, Parisi et al.
(2012), in discussing the diversification of Italian shellfish culture, reviewed
the most promising mollusk species and their culture in general (refer to
Table 1.1 for a list of the most notable farmed mollusk species worldwide).
Most mollusk culture requires no feed inputs (algae are used to feed the
larvae and juveniles in hatcheries to provide spat for mollusk culturing) but
may require control of fouling and predators. Seed bivalves are produced
either in land-based hatcheries (Robert, 2009) or from natural populations
(wild spat) (Parisi et al., 2012). They can be transported over considerable
distances to grow-out sites in estuaries and even to different countries
(FAO, 2013). Farming mollusks is limited in several countries because of
limited capacity producing seed from mollusk hatcheries and nurseries
(FAO, 2014), relying on the wild seed. The use of wild seed is impossible
if the natural populations of mollusks are not suited to culture.
9
Introduction to aquaculture
Intensification will require a reliable, plentiful, and inexpensive supply of
hatchery seed, requiring the selection and management of broodstocks
and the controlled production of high-quality seed stocks (Elston and
Ford, 2011). This would reduce the environmental biosecurity concern
of the translocation of non-native species (Parisi et al., 2012).
1.4 Crustacean aquaculture
The most recent dramatic change in aquaculture has been the explo-
sive growth in shrimp farming in Southeast Asia (Cressey, 2009). The
production has increased almost exponentially since the mid-1970s
(FAO, 2010). This rapid increase largely reflects the dramatic increase in
white leg shrimp Litopenaeus vannamei (formerly Penaeus vannamei) culture
in Asia (China, Thailand and Indonesia) and Latin America (Ecuador and
Mexico) (Bondad-Reantaso et al., 2012), where the penaeid shrimps have
tended to dominate due to high-value, short-production cycles and
accessible technologies (Bostock et al., 2010). Crustacean farming, similarly
to marine fish aquaculture, requires a high-quality diet, usually containing
fish meal and often fish oil (Bostock et al., 2010).
1.5 Chemicals in aquaculture
There is a long list of chemicals that are used in aquaculture, including
agricultural limestone, lime, fertilizers, oxidants, coagulants,
osmoregulators, algicides, herbicides, fish toxicants, antifoulants, therapeu-
tics, disinfectants, anesthetics, agricultural pesticides, and hormones (Arthur
et al., 2000; Boyd and Massaut, 1999; Boyd and Tucker, 1998; Noga, 2010;
Schnick, 2001). To mitigate the environmental impact associated with the
use of aquacultural chemicals, various regulations have been advocated
(FAO, 1997). In many countries, governmental regulations on chemical
use in aquaculture have been established (Cabello, 2006; Schnick, 1988,
2001) (refer also to Martins and Martins (2020) in Chapter 3 (Section 3.4),
Loro (2020) in Chapter 5 (Section 5.4), and de Assis (2020) in Chapter 6 in
this book. Most importing countries also have food safety regulations that
involve the inspection of incoming shipments of seafood products for
specific chemical residues. A companion textbook, Aquaculture Pharmacology
(Kibenge et al., 2020), has a comprehensive review of most aquaculture
pharmaceuticals. The pharmaceuticals used in human and veterinary
medicine (including aquaculture) and their by-products enter the aquatic
10 Frederick S.B. Kibenge
environment as pollutants in a variety of ways, causing adverse effects on
nontarget aquatic organisms. The aquatic environment may also be contam-
inated by chemicals such as agrochemicals, metals, oils and their derivatives,
and microplastics as a result of erosion of surface deposits of metal minerals,
as well as from human activities, such as agriculture, mining, smelting, fossil
fuel combustion, and industrial and commercial uses of metals (Nordberg
et al., 2007; Pandey et al., 2019). Martinez et al. discuss metal pollutants that
are toxic to aquatic animals in Chapter 4, Loro discusses agrochemical
pollutants in Chapter 5, de Assis discusses pharmaceutical pollutants in
Chapter 6, Sadauskas-Henrique et al. discuss oil and derivatives pollutants
in Chapter 7, and de Araújo et al. discuss microplastics and associated
pollutants in Chapter 8 in this book. Additional information on chemicals
in aquaculture and the contribution of aquaculture to chemical pollution
and other adverse impacts of chemical use by humans can be found in
Boyd and McNiven (2015).
1.6 Governance of aquaculture
The FAO (2017) technical guidelines on “aquaculture governance
and sector development” define aquaculture governance as “the set of
processes by which a jurisdiction manages its resources concerning aquacul-
ture, how its stakeholders participate in making and implementing decisions
affecting the sector, how government personnel are accountable to the
aquaculture community and other stakeholders, and how the respectful rule
of law is applied and enforced.” Most countries have some form of legisla-
tion governing aquaculture operations (with regard to animal welfare,
animal diseases, the environment, water use, land use, and waste disposal),
with the competent authorities residing in various government ministries
and agencies. Given the diversity of countries and aquaculture systems, it
is beyond the scope of this chapter to consider legislation in each country.
Instead, the reader is referred to a series of comparative national overviews of
aquaculture laws and regulations, “National Aquaculture Legislation
Overview (NALO),” from aquaculture producing countries that are
published by the FAO as NALO Fact sheets (FAO, 2019). These fact sheets
are updated every 2 to 3 years (FAO, 2019). At the national level, aquacul-
ture operations require various licenses and permits to operate, ensuring
environmental protection relating to the waste generated, prevention,
and control of aquatic animal diseases, and the well-being of aquaculture
animals (FAO, 2019). There are also Policy Frameworks mandated
11
Introduction to aquaculture
nationally, regionally, or internationally on how aquaculture activities are
developed and managed. These guidelines and codes of conduct provide
good practices for a variety of aquaculture operations and how the activities
are regulated in both freshwater and marine environments as well as for
land-based aquaculture. The ultimate purpose of governance of the aqua-
culture sector should be to support sustainable aquaculture by emphasizing
environmental sustainability and social responsibility. Enhancement of
aquaculture’s growth needs the right policy decisions regarding the use of
natural resources (water, land, seed, and feed), as well as sound environmen-
tal management. Good governance is fundamental to the successful
formulation and implementation of aquaculture development policies,
strategies, and plans (FAO, 2016; Hishamunda et al., 2014). Three main
environmental actions arising from good governance are: (1) management
of effluent and nutrient loading, (2) improvement of aquaculture legislation,
and (3) mandatory environmental impact assessment (EIA) (FAO, 2016;
Hishamunda et al., 2014).
References
Aarset, B., Borgen, S.O., 2015. The battle of the eyed egg: critical junctures and the control
of genes in Norwegian salmon farming. Aquaculture 445, 70–78.
Ahmad, I., Rani, A.M.B., Verma, A.K., Maqsood, M., 2017. Biofloc technology: an emerg-
ing avenue in aquatic animal healthcare and nutrition. Aquac. Int. 25, 1215–1226.
Arthur, J.R., Lavilla-Pitogo, C.R., Subasinghe, R.P. (Eds.), 2000. Use of Chemicals in
Aquaculture in Asia. Proceedings of the Meeting on the Use of Chemicals in Aquacul-
ture in Asia. Southeast Asian Fisheries Development Center, Iloilo, Philippines.
Bennet, N. 2019. Aquaculture industry is headed for a sea change. Available at https://www.
coastreporter.net/news/local-news/aquaculture-industry-is-headed-for-a-sea-change-
1.23947488 (Accessed September 16, 2019).
Bird, W., 2013. In Japan, Captive Breeding May Help Save the Wild Eel. Environment 360.
Accessible at http://e360.yale.edu/feature/in_japan_captive_breeding_may_help_
save_the_wild_eel/2700/ (Accessed September 16, 2019).
Bondad-Reantaso, M.G., Subasinghe, R.P., Josupeit, H., Cai, J., Zhou, X., 2012. The role
of crustacean fisheries and aquaculture in global food security: past, present and future. J.
Invertebr. Pathol. 110, 158–165.
Bossier, P., Ekasari, J., 2017. Biofloc technology in aquaculture to support sustainable devel-
opment goals. Microb. Biotechnol. 10, 1012–1016.
Bostock, J., McAndrew, B., Richards, R., Jauncey, K., Telfer, T., Lorenzen, K., et al., 2010.
Aquaculture: global status and trends. Philos. Trans. R. Soc. B 365, 2897–2912.
Boyd, C.E., Massaut, L., 1999. Risks associated with use of chemicals in pond aquaculture.
Aquac. Eng. 20, 113–132.
Boyd, C., McNiven, A., 2015. Aquaculture, Resource Use, and the Environment. Wiley
Blackwell, p. 349.
Boyd, C.E., Tucker, C.S. 1998. Pond Aquaculture Water Quality Management. Boston:
Kluwer Academic Publishers. 624 pp.
Boyd, C.E., McNevin, A.A., Clay, J., Johnson, H.M., 2005. Certification issues for some
common aquaculture species. Rev. Fish. Sci. 13, 231–279.
12 Frederick S.B. Kibenge
Cabello, F.C., 2006. Heavy use of prophylactic antibiotics in aquaculture: a growing problem
for human and animal health and for the environment. Environ. Microbiol. 8, 1137–
1144.
Cooke, M. 2016. BBFAW Investor Briefing – Animal Welfare in Farmed Fish. Available
from https://www.bbfaw.com/media/1432/investor-briefing-no-23-animal-welfare-
in-farmed-fish.pdf (Accessed October 03, 2019).
Cressey, D., 2009. Future fish. Nature 458, 398–400.
Daniel, N., Nageswari, P., 2017. Exogenous probiotics on biofloc based aquaculture: a
review. Curr. Agric. Res. J. 5, 88–107.
Dauda, A.B., 2019. Biofloc technology: a review on the microbial interactions, operational
parameters and implications to disease and health management of cultured aquatic ani-
mals. Rev. Aquacult., 1–18. https://doi.org/10.1111/raq.12379.
de Assis, H.C.S. 2020. Chapter 6 Pharmaceutical pollutants. In Aquaculture Toxicology.
Edited by Kibenge, F.S.B., Baldisserotto, B., Chong, R.S.M. Elsevier Inc, Academic
Press. (in preparation).
Dı́az, G.A., Seijo, L.C., Gaspar, M.B., da Costa González, F. 2011. Razor Clams: Biology,
Aquaculture and Fisheries. Consellerı́a do Mar, Xunta de Galicia ed., Santiago de Comp-
ostela, Spain. Available from: ftp://ftp.cimacoron.org/razor_clams_2011.pdf (Accessed
September 16, 2019).
Done, H.Y., Venkatesan, A.K., Halden, R.U., 2015. Does the recent growth of aquaculture
create antibiotic resistance threats different from those associated with land animal pro-
duction in agriculture? Am. Assoc. Pharm. Sci. J. 17, 513–524. https://doi.org/10.1208/
s12248-015-9722-z.
Dumbauld, B.R., Ruesink, J.L., Rumrill, S.S., 2009. The ecological role of bivalve shellfish
aquaculture in the estuarine environment: a review with application to oyster and clam
culture in west coast (USA) estuaries. Aquaculture 290, 196–223.
Elston, R.A. 1999. Health Management, Development and Histology of Seed Oysters.
World Aquaculture Society, Baton Rouge, LA, USA. 110 pp.
Elston, R.A., Ford, S.E., 2011. Chapter 13 Shellfish diseases and health management. In:
Shumway, S.E. (Ed.), Shellfish Aquaculture and the Environment, first ed. John Wiley
 Sons Inc, pp. 359–394.
Emerenciano, M.G.C., Martı́nez-Córdova, L.F., Martı́nez-Porchas, M., Miranda-Baeza, A.,
2017. Chapter 5 Biofloc Technology (BFT): A Tool for Water Quality Management in
Aquaculture. Intech, https://doi.org/10.5772/66416.
Espinal, C.A., Matuli
c, D., 2019. Chapter 3 Recirculating aquaculture technologies. In:
Goddek, S., Joyce, A., Kotzen, B., Burnell, G.M. (Eds.), Aquaponics Food Production
Systems. Springer Nature, Switzerland AG, pp. 35–76, https://doi.org/10.1007/978-3-
030-15943-6_3.
EURLFD (European Union Reference Laboratory for Fish Diseases). 2016. Scientific meet-
ing report on cleaner fish in aquaculture 2016. https://www.eurl-fish-crustacean.eu/
fish/scientific-reports (Accessed August 01, 2018).
FAO, 2010. The State of World Fisheries and Aquaculture 2010. Rome, FAO. 2010. 197 pp.
FAO, 2013. Hatchery Culture of Bivalves: A Practical Manual. FAO Fisheries Technical
Paper 471. Accessible online ftp://ftp.fao.org/docrep/fao/007/y5720e/y5720e00.pdf.
FAO, 2014. The State of World Fisheries and Aquaculture 2014. FAO, Rome. 223 pp.
FAO, 2015. Fishery statistical collections: global aquaculture production. Accessible online
http://www.fao.org/fishery/statistics/global-aquaculture-production/en Accessed: July
14, 2019.
FAO, 2016. The State of World Fisheries and Aquaculture 2016. Contributing to Food
Security and Nutrition for all. FAO, Rome. 200 pp.
FAO, 2017. Aquaculture Development. 7. Aquaculture governance and sector development.
FAO Technical Guidelines for Responsible Fisheries. No. 5. Suppl. 7. Rome, Italy. 50 pp.
13
Introduction to aquaculture
FAO, 2018.Leading Species in Global Aquaculture Production in 2016 (in million metric
tons). Statista. Statista Inc. https://www.statista.com/statistics/240268/top-global-
aquaculture-producing-countries-2010/ Accessed: July 14, 2019.
FAO, 2019. National Aquaculture Legislation Overview (NALO) Fact Sheets for different
countries. Available at http://www.fao.org/fishery/collection/nalo/en (web archive
link, 01 September 2019) and http://www.fao.org/fishery/nalo/search/en (Accessed
September 1, 2019).
FAO (Food and Agriculture Organization of the United Nations), 1997. Aquaculture Devel-
opment. FAO Technical Guidelines for Responsible Fisheries 5. FAO, Rome.
Grand View Research, Inc., 2014. Aquaculture Market Analysis By Culture Environment
(Fresh Water, Marine Water, Brackish Water), By Product (Carps, Crustaceans, Mack-
erel, Milkfish, Mollusks, Salmon, Sea Bass, Sea Bream, Trout) and Segment Forecasts To
2020. Available at: http://www.grandviewresearch.com/industry-analysis/aquaculture-
market and at: http://www.thefishsite.com/fishnews/23604/world-aquaculture-
market-to-reach-20296-billion-by-2020#sthash.STzI17Ql.dpuf (Accessed: April 02,
2016).
Gunnarsson, V.I., 2007. http://www.fisheries.is/aquaculture/species/cod/. (Accessed 2
April 2016).
Hall, S.J., Delaporte, A., Phillips, M.J., Beveridge, M., O’Keefe, M., 2011. Blue Frontiers:
Managing the Environmental Costs of Aquaculture. The WorldFish Center, Penang,
Malaysia. http://www.conservation.org/publications/documents/BlueFrontiers_
aquaculture_report.pdf. (Accessed 2 April 2016).
Hishamunda, N., Ridler, N., Martone, E. 2014. Policy and Governance in Aquaculture: Les-
sons Learned and Way Forward. FAO Fisheries and Aquaculture Technical Paper No.
577. Rome, FAO. 48pp.
Kibenge, F.S.B., Baldisserotto, B., Chong, R.S.M. (Eds.), 2020. Aquaculture Pharmacology.
Elsevier Inc, Academic Press. in preparation.
Kitada, S., 2018. Economic, ecological and genetic impacts of marine stock enhancement and
sea ranching: a systematic review. Fish Fish. 19, 511–532.
Kramer, L. 2015. Land-based salmon aquaculture: a future with potential. Available at
https://www.seafoodsource.com/news/aquaculture/land-based-salmon-aquaculture-
a-future-with-potential (Accessed September 16, 2019).
Loro, V.L., 2020. Chapter 5 Agrochemicals: Contamination of environment, effects on wild-
life, strategies for mitigating impacts and new perspectives to legislation. In: Kibenge, F.S.
B., Baldisserotto, B., Chong, R.S.M. (Eds.), Aquaculture Toxicology. Elsevier Inc, Aca-
demic Press. in preparation.
Lovatelli, A., Aguilar-Manjarrez, J., Soto, D. (Eds.) 2013. Expanding mariculture farther off-
shore—Technical, environmental, spatial and governance challenges. FAO Technical
Workshop. 22–25 March. 2010. Orbetello, Italy. FAO Fisheries and Aquaculture Pro-
ceedings No. 24. Rome, FAO. 73 pp. Includes a CD–ROM containing the full docu-
ment (314 pp). (also available at http://www.fao.org/docrep/018/i3092e/i3092e00.
htm).
Martins, S.E., Martins, C.M.G., 2020. Chapter 3 Antifoulants and disinfectants. In: Kibenge,
F.S.B., Baldisserotto, B., Chong, R.S.M. (Eds.), Aquaculture Toxicology. Elsevier Inc,
Academic Press. in preparation.
Masuda, Y., Imaizumi, H., Oda, K., Hashimoto, H., Usuki, H., Teruya, K., 2012. Artificial
completion of the Japanese Eel, Anguilla japonica, life cycle: challenge to mass production.
Bull. Fisheries Res. Agency 35, 111-117. Accessible online https://www.fra.affrc.go.jp/
bulletin/bull/bull35/35-13.pdf.
Noga E.J. 2010. Fish Disease, Diagnosis and Treatment, second ed. Iowa State Press, Ames,
Iowa. 536 pp.
14 Frederick S.B. Kibenge
Nordberg, G.F., Fowler. B.A., Nordberg, M., Friberg, L.T., 2007. Handbook on the Tox-
icology of Metals, third ed. Elsevier, Amsterdam. 1024 pp.
OECD/FAO, 2019. OECD-FAO Agricultural Outlook 2019-2028. OECD Publishing,
Paris/Food and Agriculture Organization of the United Nations, Rome, https://doi.
org/10.1787/agr_outlook-2019-en.
Owen, E., 2018. China gets ready to harvest first batch of farmed salmon from huge, deep sea
fully-submersible fish cage. Available at https://salmonbusiness.com/chinas-gets-ready-
to-harvest-first-batch-of-farmed-salmon-from-huge-deep-sea-fully-submersible-fish-
cage/ (Accessed November 21, 2018).
Pandey, L.K., Park, J., Son, D.H., Kim, W., Islam, M.S., Choi, S., Lee, H., Han, T., 2019.
Assessment of metal contamination in water and sediments from major rivers in South
Korea from 2008 to 2015. Sci. Total Environ. 651, 323–333.
Parisi, G., Centoducati, G., Gasco, L., Gatta, P.P., Moretti, V.M., Piccolo, G., Roncarati, A.,
Terova, G., Pais, A., 2012. Molluscs and echinoderms aquaculture: biological aspects,
current status, technical progress and future perspectives for the most promising species
in Italy. Ital. J. Anim. Sci. 11, 4. https://doi.org/10.4081/ijas.2012.e72.
Park, Y.H., Hwang, S.Y., Hong, M.K., Kwon, K.H., 2012. Use of antimicrobial agents in
aquaculture. Revue Scientifique et Technique (International Office of Epizootics) 31,
189–197.
Powell, A., Treasurer, J.W., Pooley, C.L., Keay, A.J., Lloyd, R., Imsland, A.K., de Leaniz,
C.G., 2018. Use of lumpfish for sea-lice control in salmon farming: challenges and
opportunities. Rev. Aquac. 10, 683–702.
Real, N. 2010. DFO recognises potential of closed containment methods. Available at
http://fis.com/fis/worldnews/worldnews.asp?l¼endb¼1id¼39422.
Robert, R., 2009. Review on molluscs hatchery nursery development in Europe. pp 1–12.
In: Proc. Symp. EAS, EUROSHELL Session, Trondheim, Norway.
Roberts, R.J., Shepherd, C.J., 1974. Handbook of Trout and Salmon Diseases. Fishing
News, Surrey, England, pp. 40–42.
Sapin, R., Korban, D., Unlay, N., 2020. What are land-based salmon companies doing to
tackle off flavors? Available at https://www.intrafish.com/aquaculture/we-asked-
every-major-land-based-salmon-farmer-how-theyre-tackling-off-flavor-problems-
heres-what-they-said-/2-1-752023?utm_campaign¼IFCO%3A%20Monthly%
20Land-Based%20Salmon%20-%20Mar%202020utm_source¼hs_emailutm_
medium¼emailutm_content¼85265239_hsenc¼p2ANqtz-_
9KtqcaHfzksx8cItMBR6noN-
IZC4x3a4Rwm7yjAelXkIOT7Kz288k2I8MmMU6zG-JbLN8bSlWeT4UQi4KtcC_
ALW1EA_hsmi¼85266785 (Accessed March 26, 2020).
Schnick, R.A., 1988. The impetus to register new therapeutants for aquaculture. Progressive
Fish-Culturist 50, 190–196.
Schnick, R.A., 2001. Aquaculture chemicals. In: Kirk-Othmer Encyclopedia of Chemical
Technology, fourth ed. vol. 3. John Wiley  Sons, New York, pp. 209–225.
Shepherd, J., 1993. Aquaculture systems. In: Brown, L. (Ed.), Aquaculture for Veterinarians:
Fish Husbandry and Medicine. Pergamon Press Ltd., Oxford, pp. 43–55.
Shore, R. 2019. U.S. firm seeks stake in B.C.’s only land-based Atlantic salmon farm. https://
vancouversun.com/news/local-news/u-s-firm-seeks-majority-stake-in-b-cs-only-
land-based-salmon-farm.
Skiftesvik, A.B., Blom, G., Agnalt, A.-L., Durif, C.M.F., Browman, H.I., Bjelland, R.M.,
Harkestad, L.S., Farestveit, E., Paulsen, O.I., Fauske, M., Havelin, H., Johnsen, K.,
Mortensen, S., 2014. Wrasse (Labridae) as cleaner fish in salmonid aquaculture—the
Hardangerfjord as a case study. Mar. Biol. Res. 10, 289–300. https://doi.org/
10.1080/17451000.2013.810760.
15
Introduction to aquaculture
SPC, 2011. SPC Aquaculture Portal, Commodities Carp. Accessible here https://www.spc.
int/aquaculture/images/commodities/pdf/Carp_page.pdf.
Tal, Y., Schreier, H.J., Sowers, K.R., Stubblefield, J.D., Place, A.R., Zohar, Y., 2009. Envi-
ronmentally sustainable land-based marine aquaculture. Aquaculture 286, 28–35.
Tran, K., 2019. Egypt tops Norway, Chile in Aquaculture Production. https://www.
intrafish.com/aquaculture/egypt-tops-norway-chile-in-aquaculture-production/2-1-
707157. (Accessed 22 April 2020).
Welch, A.W., Knapp, A.N., El Tourky, S., Daugherty, Z., Hitchcock, G., Benetti, D., 2019.
The nutrient footprint of a submerged-cage offshore aquaculture facility located in the
tropical Caribbean. J. World Aquacult. Soc. 50, 299–316. https://onlinelibrary.wiley.
com/doi/full/10.1111/jwas.12593.
Wever, L., Krause, G., Buck, B.H., 2015. Lessons from stakeholder dialogues on marine
aquaculture in offshore windfarms: perceived potentials, constraints and research gaps.
Mar. Policy 51, 251–259.
White, P., Edwards, P., 2015. Types of culture systems and aqua-ecosystems. Available at
http://aquaculture.management/2015/types-of-culture-systems-and-aqua-
ecosystems/ (Accessed March 26, 2020).
World Bank, 2013. Fish to 2030: Prospects for Fisheries and Aquaculture (English). Agricul-
ture and Environmental Services Discussion Paper; no. 3. World Bank Group, Washing-
ton, DC. http://documents.worldbank.org/curated/en/458631468152376668/Fish-
to-2030-prospects-for-fisheries-and-aquaculture. (Accessed 3 October 2019).
16 Frederick S.B. Kibenge
CHAPTER TWO
General introduction to toxicology
of aquatic animals
Bernardo Baldisserotto
Department of Physiology and Pharmacology, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
2.1 Introduction to toxicology
Laboratory studies dealing with exposure to pollutants can last for
hours to a few days (acute experiments) and are usually used to calculate
the concentration that affects (effective concentration—EC50) or kills (lethal
concentration—LC50) 50% of test organisms. Chronic studies are used to
determine threshold concentrations (no observed effect concentration, or
NOEC; lowest observed effect concentration, or LOEC). These values
can be used to compare the effect of a given pollutant in different species
or different pollutants between themselves.
These values are used worldwide to derive water quality guidelines for
the protection of aquatic life, i.e., concentrations that should result in a neg-
ligible effect on aquatic biota. Two basic guideline derivation methodolo-
gies are in use throughout the world to calculate these concentrations
(Nugegoda and Kibria, 2013): one is the assessment factor method, which
involves multiplying the lowest value of a set of toxicity data by a factor
to arrive at a criterion value. For example, the LC50 value is multiplied
by 0.01 and the NOEC value by 0.1. The assessment factor can vary
according to the country and the amount of toxicological studies available.
The other method is the species sensitivity distribution, a statistical extrap-
olation involving the use of individual toxicity data for a range of species to
determine the criterion value. This method estimates the concentration of a
substance that is predicted to protect 95% of all aquatic species extrapolating
from an equation or curve that considers the relationship between probabil-
ity x log LC50 and NOEC. Some countries use either one of the methods,
and others use a combination of both methods.
Aquaculture Toxicology © 2021 Elsevier Inc.
https://doi.org/10.1016/B978-0-12-821337-7.00004-9 All rights reserved.
17
2.2 Water quality criteria/guidelines
The United States Environmental Protection Agency (USEPA) has
water quality criteria/guidelines for water quality, and its website contains
tables with the highest concentration of the most common metals, pesticides
(mainly insecticides), and other pollutants or contaminants that are not
expected to pose a significant risk to the majority of species in a given envi-
ronment (USEPA, 2019). The same agency maintains the ECOTOX
Knowledgebase Explore function (https://cfpub.epa.gov/ecotox/explore.
cfm), which is an interactive way to examine search paths by chemical, spe-
cies, and effects.
The guidelines of the Canadian Council of Ministers of the Environment
(CCME, 2003) explain that some water quality parameters can affect the
toxicity of contaminants. Some are described later.
– pH: At alkaline pH, many metals form insoluble hydroxides or carbon-
ates that precipitate, while at acidic pH, a higher release of metals from
the sediments can occur (CCME, 2003). Water pH may also influence
toxicity in pharmaceuticals because the toxicity of sertraline and fluox-
etine was higher and diclofenac was lower at pH8.2 than at pH5.8, but
the toxicity of ethinyl estradiol was not affected by pH. Probably these
differences are due to the higher uptake of sertraline at pH8.2 and no
change in ethinyl estradiol uptake by pH (Alsop and Wilson, 2019).
The piscicide 3-trifluoromethyl-4-nitrophenol (TFM), which is applied
in the Great Lakes to control streams infested with larval sea lamprey
(Petromyzon marinus), has 5.5-fold higher uptake rates at low pH
(6.86) compared to alkaline pH (8.78). This higher uptake is most likely
because the unionized, lipophilic form of TFM exists in greater amounts
at a lower pH. On the contrary, the elimination rates are 1.7–1.8-fold
higher at pH8.78 than at pH6.86, indicating that TFM is more effective
at low pH (Hlina et al., 2017).
– Hardness and alkalinity: The increase of water hardness usually reduces
the toxicity of many metals, largely due to the formation of metal-
carbonate complexes and Ca2+
and/or Mg2+
antagonism (Blewett
and Leonard, 2017). CCME (2003) presents equations in which the
values of water hardness are used to predict the concentrations of zinc
and copper to protect aquatic life. The toxicity of the insecticides endosul-
fan (Thiodan; 1,4,5,6,7-hexachloro-8,9,10-trinorborn-5-en-2,3-yelen)
18 Bernardo Baldisserotto
(dimethyl) sulfite and methiocarb [Mesurol; 3,5-dimethyl-4-(methylthio)
phenyl methylcarbamate] to rainbow trout, Oncorhynchus mykiss, is lower
at higher alkalinity (40–121mg CaCO3/L) than at lower alkalinity
(19–20mg CaCO3/L), but hardness ranging from 50 to 147mg
CaCO3/L had no effect (Altinok et al., 2006; Capkin et al., 2006).
Hardness (6–309mg CaCO3/L) also did not affect the toxicity of another
insecticide, fenvalerate, to bluegill (Lepomis macrochirus) (Dyer et al., 1989).
The increase of hardness increases surfactant toxicity to aquatic species in
some cases, but the outcome is compound and species-specific
(Lewis, 1992).
– Salinity: The toxicity of metals in general decreases with the increase of
salinity due to complexation with seawater ions (Blewett and Leonard,
2017; Tan et al., 2019). For example, nickel may complex with SO4
2
and Cl and free nickel reduces (Blewett and Leonard, 2017). The same
complexation with Cl can be observed with cadmium (Tan et al.,
2019). The uptake of cadmium and zinc by the teleost Acanthopagrus
schlegelii reduced with the increase of salinity, probably due to the higher
waterborne Ca2+
levels at higher salinities, because both metals use the
Ca2+
uptake pathway (Zhang and Wang, 2007). Salinity does not affect
LC50 of fenvalerate to bluegill, but the accumulation of this insecticide
decreased with the increase of salinity (Dyer et al., 1989).
– Total dissolved solids: It can change the complexing and precipitation
processes of metals (CCME, 2003). The presence of suspended solids
and naturally occurring dissolved substances decreases the bioavailability
of cationic surfactants but not that of anionic and nonionic surfactants
(Lewis, 1992).
– Temperature: Besides the direct effect of temperature on the metabo-
lism of ectothermic animals, it can also affect the toxicity of several pol-
lutants. The effect depends on the pollutant (CCME, 2003).
– Dissolved oxygen: The toxicity of pollutants can be magnified by low
dissolved oxygen levels (CCME, 2003).
– Dissolved organic matter (DOM): This can also affect the toxicity of
metals. The major chemical components of DOM are humic substances
(humic and fulvic acids). Its protective effect varies according to its ori-
gin and composition. Overall, darker organic matter is expected to be
more protective against metal toxicity (Al-Reasi et al., 2013). DOC also
decreased uptake and toxicity of sertraline, but not of ethinyl estradiol
(Alsop and Wilson, 2019).
19
General introduction to toxicology of aquatic animals
Water quality guidelines in China are in the “Surface Water Environmental
Quality Standards” GB3838-2002 (http://www.codeofchina.com/
standard/GB3838-2002.html). This guide considers that class II water is
for “precious fish reserves” and up to class III water is adequate for “winter-
ing grounds of fish and shrimp, migration channels, aquaculture areas of
fishing waters.” The fourth amendment of this guideline used the data from
native species and the assessment factor method and/or species sensitivity
distribution to calculate concentrations that should result in a negligible
effect on aquatic biota (Zhao et al., 2018). However, the eutrophication
control management is incomplete compared to developed countries
because it is based only on total nitrogen and total phosphorus values
(Su et al., 2017).
South Africa has a very recent and complete guideline of water quality
for coastal marine waters for use to mariculture with maximum values for
several pollutants, based on the values from USEPA, CCME, and EU
(2013), as well as from other African countries (RSA-DEA, 2018). From
Latin America, Brazil follows the resolution from the Brazilian National
Environment Council (CONAMA, 2005), which has specific tables with
maximum values for contaminants for fisheries and aquaculture for fresh-,
brackish-, and saline waters. Mexico, on the contrary, uses only four water
quality parameters (biochemical and chemical demand of oxygen, fecal coli-
forms, total suspended solids) to indicate water quality (Comisión Nacional
del Agua, 2018). This country has also a law that states maximum values of
fats, oils, and a few metals (NOM, 1998).
2.3 Intraspecies variation of toxicity
The effects of metals and pharmaceuticals in fish can be affected by sex,
size, “personality” (defined as bold or shy, according to their risk-taking
behaviors), and social status. For example, different responses were observed
in males and females of zebrafish, Danio rerio, to cocaine, and subordinate
rainbow trout are more vulnerable than dominant ones to copper and silver
exposure (Demin et al., 2019). Survival of rainbow trout exposed to endo-
sulfan was significantly increased with increasing fish size (Capkin et al.,
2006), but the opposite was observed in those exposed to methiocarb
(Altinok et al., 2006).
20 Bernardo Baldisserotto
2.4 Models to predict toxicity of contaminants
2.4.1 Biotic ligand model (BLM)
The USEPA uses the BLM to predict dissolved metal concentrations that
correspond to lethal accumulations of a metal on biotic ligands for unique
water compositions, i.e., depends on the concentrations of some cations
(e.g., K+
, Na+
, Ca2+
, Mg2+
, and H+
). BLMs are computational models that
determine metal speciation and predict metal toxicity to biota in aqueous
systems and combine an equilibrium geochemical speciation model, a
metal–organic binding model, and a toxicological model (Smith et al.,
2015). This methodology was applied mainly for copper (USEPA, 2007),
but there are data from the USA and Canadian species for other metals
and there are also proposals to analyze the mixture of metals (Balistrieri
and Mebane, 2014). The binary metal interactions tested (silver, cadmium,
copper, nickel, lead, and zinc) demonstrated interactions, mostly inhibitory,
nonreciprocal, and caused by silver or copper (Cr
emazy et al., 2019). Nev-
ertheless, BLMs must be constructed for different water qualities and species.
For example, LC50 for copper in cardinal tetra Paracheirodon axelrodi from the
ion-poor blackwater Rio Negro, Amazon (high level of DOC) was not
predicted properly using BLM models developed using temperate DOC
and temperate species (Cr
emazy et al., 2016).
2.4.2 Toxicokinetic-toxicodynamic (TK-TD) models
These models consider the processes that lead to toxicity at the organisms
over time instead of at a certain endpoint (96h, for example), as the
BLM. Nevertheless, these models use BLM-estimated binding constants cal-
culated with toxicity data. The TK-TD models simulate the temporal
aspects of toxicity and provide a conceptual framework to better understand
the causes for variability in different species’ sensitivity to the same com-
pound as well as the causes for different toxicity of different compounds
to the same species (Giesy et al., 2010). Recent models can predict metal
toxicity as a function of the waterborne concentrations of some cations
(Feng et al., 2018a) and the mixture of metals (Gao et al., 2016). The inter-
actions between metals may be time-dependent (Feng et al., 2018b). These
models are also useful to extrapolate toxicity of pesticides from relatively
21
General introduction to toxicology of aquatic animals
constant to relatively variable exposure profiles, because in the environment,
they generally occur in fluctuating and highly variable patterns (Ashauer
et al., 2013).
2.4.3 Principal component analysis (PCA)
The PCA is a multivariate statistical procedure that uses an orthogonal trans-
formation to convert a set of correlated variables into a set of values of lin-
early uncorrelated variables called principal components, where the first
principal component has the largest possible variance and each succeeding
component in turn has the highest variance possible. Plotting the principal
components can elucidate potential correlations between the set of variables
(Marques et al., 2019).
2.4.4 Generalized additive modeling (GAM)
The GAM approach is an extension of the generalized linear model (GLM).
It is a generalized linear model with a linear predictor involving a sum of
smooth functions of covariates that allows a flexible description of complex
responses to environmental changes. Therefore, it can allow statistical infer-
ence to nonlinear correlations between the contaminant levels and bio-
marker responses. Consequently, it provides a model to predict the
bioaccumulation of chemical contaminants based on biomarker responses
and vice-versa, besides other influencing factors, such as seasonality and gra-
dients in water chemistry parameters (Marques et al., 2019).
References
Al-Reasi, H.A., Wood, C.M., Smith, D.S., 2013. Characterization of freshwater natural dis-
solved organic matter (DOM): mechanistic explanations for protective effects against
metal toxicity and direct effects on organisms. Environ. Int. 59, 201–207.
Alsop, D., Wilson, J.Y., 2019. Waterborne pharmaceutical uptake and toxicity is modified by
pH and dissolved organic carbon in zebrafish. Aquat. Toxicol. 210, 11–18.
Altinok, I., Capkin, E., Karahan, S., Boran, M., 2006. Effects of water quality and fish size on
toxicity of methiocarb, a carbamate pesticide, to rainbow trout. Environ. Toxicol.
Pharmacol. 22 (1), 20–26.
Ashauer, R., Thorbek, P., Warinton, J.S., Wheeler, J.R., Maund, S., 2013. A method to
predict and understand fish survival under dynamic chemical stress using standard
ecotoxicity data. Environ. Toxicol. Chem. 32 (4), 954–965.
Balistrieri, L.S., Mebane, C.A., 2014. Predicting the toxicity of metal mixtures. Sci. Total
Environ. 466, 788–799.
Blewett, T.A., Leonard, E.M., 2017. Mechanisms of nickel toxicity to fish and invertebrates
in marine and estuarine waters. Environ. Pollut. 223, 311–322.
Capkin, E., Altinok, I., Karahan, S., 2006. Water quality and fish size affect toxicity of endo-
sulfan, an organochlorine pesticide, to rainbow trout. Chemosphere 64 (10), 1793–1800.
22 Bernardo Baldisserotto
CCME (Canadian Council of Ministers of the Environment), 2003. Canadian Water Quality
Guidelines for the Protection of Aquatic Life: Guidance on the Site-Specific Application
of Water Quality Guidelines in Canada: Procedures for Deriving Numerical Water
Quality Objectives.
Comisión Nacional del Agua, 2018. Estadisticas del Agua en M
exico. Secretarı́a de Medio
Ambiente y Recursos Naturales, Ciudad de M
exico.
CONAMA (Conselho Nacional do Meio Ambiente), 2005. Resolução CONAMA Nº 357,
from March 17th, 2005.
Cr
emazy, A., Wood, C.M., Smith, D.S., Ferreira, M.S., Johannsson, O.E., Giacomin, M.,
Val, A.L., 2016. Investigating copper toxicity in the tropical fish cardinal tetra
(Paracheirodon axelrodi) in natural Amazonian waters: measurements, modeling, and real-
ity. Aquat. Toxicol. 180, 353–363.
Cr
emazy, A., Brix, K.V., Wood, C.M., 2019. Using the biotic ligand model framework to
investigate binary metal interactions on the uptake of Ag, Cd, Cu, Ni, Pb and Zn in the
freshwater snail Lymnaea stagnalis. Sci. Total Environ. 647, 1611–1625.
Demin, K.A., Lakstygal, A.M., Alekseeva, P.A., Sysoev, M., Abreu, M.S., Alpyshov, E.T.,
Serikuly, N., Wang, D.M., Wang, M.Y., Tang, Z.C., Yan, D.N., Strekalova, T.V., Vol-
gin, A.D., Arnstislayskaya, T.G., Wang, J.J., Song, C., Kalueff, A.V., 2019. The role of
intraspecies variation in fish neurobehavioral and neuropharmacological phenotypes in
aquatic models. Aquat. Toxicol. 210, 44–55.
Dyer, S.D., Coats, J.R., Bradbury, S.P., Atchison, G.J., Clark, J.M., 1989. Effects of water
hardness and salinity on the acute toxicity and uptake of fenvalerate by bluegill (Lepomis
macrochirus). Bull. Environ. Contam. Toxicol. 42 (3), 359–366.
EU (European Union), 2013. Directive 2013/39/EU of the European Parliament and of the
Council of 12 August 2013. Off. J. Eur. Union 2008, L348/84-97.
Feng, J.F., Gao, Y.F., Chen, M., Xu, X., Huang, M.D., Yang, T., Chen, N., Zhu, L., 2018a.
Predicting cadmium and lead toxicities in zebrafish (Danio rerio) larvae by using a
toxicokinetic-toxicodynamic model that considers the effects of cations. Sci. Total Envi-
ron. 625, 1584–1595.
Feng, J.F., Gao, Y.F., Ji, Y.J., Zhu, L., 2018b. Quantifying the interactions among metal
mixtures in toxicodynamic process with generalized linear model. J. Hazard. Mater.
345, 97–106.
Gao, Y.F., Feng, J.F., Han, F., Zhu, L., 2016. Application of biotic ligand and toxicokinetic-
toxicodynamic modeling to predict the accumulation and toxicity of metal mixtures to
zebrafish larvae. Environ. Pollut. 213, 16–29.
Giesy, J.P., Naile, J.E., Khim, J.S., Jones, P.D., Newsted, J.L., 2010. Aquatic toxicology of
perfluorinated chemicals. Rev. Environ. Contam. Toxicol. 202, 1–52.
Hlina, B.L., Tessier, L.R., Wilkie, M.P., 2017. Effects of water pH on the uptake and elim-
ination of the piscicide, 3-trifluoromethyl-4-nitrophenol (TFM), by larval sea lamprey.
Comp. Biochem. Physiol. Part C: Toxicol. Pharmacol. 200, 9–16.
Lewis, M.A., 1992. The effects of mixtures and other environmental modifying factors on the
toxicities of surfactants to fresh-water and marine life. Water Res. 26 (8), 1013–1023.
Marques, D.D., Costa, P.G., Souza, G.M., Cardozo, J.G., Barcarolli, I.F., Bianchini, A.,
2019. Selection of biochemical and physiological parameters in the croaker Micropogonias
furnieri as biomarkers of chemical contamination in estuaries using a generalized additive
model (GAM). Sci. Total Environ. 647, 1456–1467.
NOM, 1998. Norma Oficial Mexicana NOM-002-ECOL-1996. In: Secretarı́a de Medio
Ambiente, Recursos Naturales y. Pesca, Mexico.
Nugegoda, D., Kibria, G., 2013. Water quality guidelines for the protection of aquatic eco-
systems. In: F
erard, J.-F., Blaise, C. (Eds.), Encyclopedia of Aquatic Ecotoxicology.
Springer Science + Business Media, Dordrecht. https://doi.org/10.1007/978-94-
007-5704-2.
23
General introduction to toxicology of aquatic animals
RSA-DEA (Republic of South Africa, Department of Environmental Affairs), 2018. South
African Water Quality Guidelines for Coastal Marine Waters - Natural Environment and
Mariculture Use. Cape Town.
Smith, K.S., Balistrieri, L.S., Todd, A.S., 2015. Using biotic ligand models to predict metal
toxicity in mineralized systems. Appl. Geochem. 57, 55–72.
Su, J., Ji, D.F., Lin, M., Chen, Y.Q., Sun, Y.Y., Huo, S.L., Zhu, J.C., Xi, B.D., 2017. Devel-
oping surface water quality standards in China. Resour. Conserv. Recycl. 117, 294–303.
Tan, Q.G., Lu, S.H., Chen, R., Peng, J.H., 2019. Making acute tests more ecologically rel-
evant: cadmium bioaccumulation and toxicity in an estuarine clam under various salin-
ities modeled in a toxicokinetic-toxicodynamic framework. Environ. Sci. Technol. 53
(5), 2873–2880.
USEPA (United States Environmental Protection Agency), 2007. Aquatic Life Ambient
Freshwater Quality Criteria—Copper: 2007 Revision. U.S. Environmental Protection
Agency; 2007204.
USEPA (United States Environmental Protection Agency), 2019. National Recommended
Water Quality Criteria—Aquatic Life Criteria Table. https://www.epa.gov/wqc/
national-recommended-water-quality-criteria-aquatic-life-criteria-table#table
(Accessed April 26th, 2019).
Zhang, L., Wang, W.X., 2007. Waterborne cadmium and zinc uptake in a euryhaline teleost
Acanthopagrus schlegeli acclimated to different salinities. Aquat. Toxicol. 84 (2), 173–181.
Zhao, X.L., Wang, H., Tang, Z., Zhao, T.H., Qin, N., Li, H.X., Wu, F.C., Giesy, J.P.,
2018. Amendment of water quality standards in China: viewpoint on strategic consid-
erations. Environ. Sci. Pollut. Res. 25 (4), 3078–3092.
24 Bernardo Baldisserotto
CHAPTER THREE
Antifoulants and disinfectants
Samantha Eslava Martinsa,b
and Camila de Martinez Gaspar Martinsb
a
Norwegian Institute for Water Research (NIVA), Ecotoxicology and Risk Assessment Section, Oslo, Norway
b
Universidade Federal do Rio Grande—FURG, Instituto de Ci^
encias Biológicas, Rio Grande/RS, Brazil
3.1 Overview
In the past 50years, the primary aquatic food supply for humans chan-
ged from wild-caught to production in farms. Aquaculture increased not
only in the levels of production, but in the types of species cultivated, driven
by high demand in a globalized environment. In 2014, the contribution of
aquaculture to the production of fish for human consumption outweighed
the acquisition of fish through wild fishing. Currently, the aquaculture sec-
tor plays an important role in food security and livelihood, being the source
of income and social development. Fish and fishery goods represent one of
the most-traded segments of the world food sector, with a high international
trade competition. For several countries and for numerous coastal and riv-
erine regions, production of fish and fishery products is essential to their
economies, accounting for more than 40% of the total value of traded com-
modities in some countries, mainly islands. This represents a value 9% of
global agricultural exports and 1% of world commodity trade (FAO,
2016). This impressive growth of the aquaculture sector was possible
through the development of technologies that confer improved productiv-
ity, allowing the production of aquatic animals in line with the increasing
demand for seafood as a source of animal protein. However, major con-
straints impinging aquaculture include the biofouling on aquaculture equip-
ment and infrastructure, and the losses from diseases.
Biofouling is of major concern in both shipping and aquaculture indus-
tries. In the shipping industry, biofouling brings economic constraints
because fouled organisms result in the deformation of the shape of hulls
and hence the hydrodynamics of the boat, leading to an increase in the fric-
tional drag and thereby fuel consumption (Abbott et al., 2000). Biofouling is
a problem especially for sea cage-based finfish aquaculture where impacts are
well documented. In particular, a major concern with the fouling of cages is
the occlusion of netting mesh, which restricts water flow resulting in
Aquaculture Toxicology © 2021 Elsevier Inc.
https://doi.org/10.1016/B978-0-12-821337-7.00005-0 All rights reserved.
25
reduced water quality (De Nys and Guenther, 2009). Another major chal-
lenge is the development of effective disease treatment and prevention.
Studies have shown that caged salmon may come in contact with nemato-
cysts of fouling cnidarians when nets are cleaned and hydroids are released
into the water (Bloecher et al., 2018; Floerl et al., 2016). Hydroid’s nema-
tocysts lead to irritation and pathological damage to salmon gills and may
facilitate the spread of the amoebic gill disease (AGD), an increasing threat
to Atlantic salmon farming (Bloecher et al., 2018). In this sense, in order to
maintain optimum culture conditions and ensure aquaculture as a profitable
industry, proper husbandry techniques are mandatory, requiring that anti-
fouling biocides are used to minimize biofouling.
About 90% of the aquaculture occurs in developing countries, and the
production losses due to disease reach up to 6 billion dollars per annum
(Assefa and Abunna, 2018; Leung and Bates, 2013). The proliferation of
opportunistic pathogens (bacteria, virus, fungi, or protozoa) is driven by
the high density of fish stocks and the feed wastes; thus, the use of quick
and effective antipathogens is necessary (Castillo-Rodal et al., 2012;
Twiddy et al., 1995). Therefore, disinfection is commonly used in aquacul-
ture facilities.
3.2 Definitions and uses
3.2.1 Antifoulants
When an object is placed into water, microorganisms followed by algae and
animals start to adhere to it. This process is termed biofouling, defined as the
settlement and attachment of organisms on the external surfaces of sub-
merged or semisubmerged objects (Lewis, 1998). Antifouling technologies
have developed to protect structures against biofouling.
Antifouling coatings have been used for many centuries. The Phoeni-
cians and Carthaginians were the first to use pitch and likely copper sheeting
to prevent the settlement of organisms on the bottom of wooden ships
(Hellio and Yebra, 2009). From the late 18th century, the use of metals
in coatings increased successfully and these compounds, particularly copper,
are still incorporated into modern coatings (Dafforn et al., 2011). The effi-
cacy of metals as antifoulants can be enhanced by co-biocides (or booster
biocides) in the painting formulations. Such co-biocides found their market
from the early 1960s when organotin-based paints were introduced as
marine antifoulants and believed to be the solution to preventing biofouling
26 Samantha Eslava Martins and Camila de Martinez Gaspar Martins
(Yebra et al., 2004). However, severe impacts on the marine environment
occurred following the introduction of tributyltin (TBT), including the
well-known phenomenon of imposex, which decimated the marine gastro-
pod Nucella lapillus in coastal areas of Southwest England (Gibbs and Bryan,
1996). The severity of adverse ecological effects of organotin-based anti-
foulants culminated in the gradual restriction until the global ban of TBT
as an active ingredient in antifouling paints, in 2008 (AkzoNobel, 2000;
Dafforn et al., 2011). Subsequently, organotin-free technologies flooded
the paint market, turning paint formulations into a mixture of inorganic bio-
cides (typically cuprous oxide) and one or more organic/organometallic co-
biocides (Hellio and Yebra, 2009), such as Irgarol 1051, Diuron, DCOIT
(Seanine), chlorothalonil, dichlofluanid, TCMTB, thiram, zinc pyrithione
(ZnPT), and copper pyrithione (CuPT) (Castro et al., 2011; Hellio and
Yebra, 2009). Such co-biocides are not expected to leach into the water
bodies to trigger toxic concentrations to nontarget species (Hellio and
Yebra, 2009). However, it is already known that several organisms may
be very sensitive to such antifoulants, particularly during the early life stages,
including farmed aquatic animals (Martins et al., 2018).
3.2.2 Disinfectants
Disinfectants are used in intensive cultures, particularly in finfish and shrimp
hatcheries and grow-out ponds in routine practices to disinfect culture facil-
ities and equipment, to maintain hygiene throughout the production cycle,
and often to treat bacterial disease outbreaks. A disinfectant is an agent that
destroys infection-producing organisms. In this sense, disinfectants can act
on microorganisms in two distinct ways: (1) through growth inhibition
(bacteriostasis and fungistasis) or (2) through lethal action (bactericidal, fun-
gicidal, or virucidal effects). The particular reason for disinfection will deter-
mine the disinfection strategy used and how it should be applied.
General practices of the disinfection of aquaculture systems involve the
application of chemical compounds in sufficient concentrations, and for suf-
ficient periods, to kill or reduce the pathogenic organisms, mainly virus and
fungus, avoiding the loss of production. Essential disinfection protocols
include: (1) removal of all aquatic animals (both dead and alive) from the
facility; (2) a deep cleaning and washing to eliminate remaining organic mat-
ter adhered to the surfaces; (3) the application of disinfectants on equipment
and installations; (4) a final wash; and (5) the neutralization using chemical
products, if needed. The disposal of diseased animals should not be done in
27
Antifoulants and disinfectants
receiving waters due to the risk of contamination of wild populations or
neighboring farms that use the same water supply. Therefore, the animals
must be euthanized and collected by a company designed to treat or store
hazardous waste. The disinfectants must be stored in such a way that they
will not pose direct or indirect dangers to animal or human health and
the environment (OIE - World Organisation for Animal Health, 2009).
Among the most used disinfectants are formaldehyde, hydrogen perox-
ide, chlorine, potassium permanganate, isopropyl alcohol, iodophors,
peracetic acid and quaternary ammonium compounds (Bowker et al.,
2014; Scarfe et al., 2006). In general, they are characterized by high solubility
and low persistence in the aquatic environment. The efficacy and character-
istics of the commonly used disinfectants are summarized in Table 3.1 (Kohn
et al., 2017; Rico et al., 2012).
3.3 Mode of action
3.3.1 Antifoulants
The mode of action of antifouling biocides depends on the target organisms
for which the formulation was designed for. Antifouling herbicides such as
Irgarol 1051 and Diuron act by inhibiting the transport of electrons during
photosystem II (Hall et al., 1999), affecting photosynthetic organisms. Anti-
fouling fungicides may act through different mechanisms. Chlorothalonil
acts through the inhibition of glycolysis or depleting glutathione (Caux
et al., 1996); despite being designed to act as a fungicide, the presence of
multiple reactive electrophilic centers makes chlorothalonil extremely toxic
Table 3.1 Efficacy and characteristics of commonly used disinfectants.
Disinfectant Efficacy
Target organism
Virus Bacteria
Bacterial
spore Fungi
Spore-forming
protozoan
Formaldehyde High + + + + +
H2O2 High + + VA + +
PAA High + + + + +
Chlorine High + + VA + LA
Iodophors Intermediate + +  + LA
QACs Low VA VA  + 
Ozone High + + VA + LA
QACs, quaternary ammonium compounds; PAA, peracetic acid; +, effective; , nonrecommended;
VA, variable activity; LA, limited activity. Information on specific efficacies followed Scarfe et al.
(2006) and AQUAVETPLAN (2008).
28 Samantha Eslava Martins and Camila de Martinez Gaspar Martins
to nontarget aquatic organisms (Castro et al., 2011), causing effects in ani-
mals and plants. Dichlofluanid is a potent inhibitor of fungal spore germina-
tion (PPDB, 2007–2017), but its degradation products may play a major role
in toxicity since dichlofluanid quickly undergoes hydrolysis in water
(Schouten et al., 2005). Thiram inhibits spore germination and mycelial
growth (PPDB, 2007–2017) as well as nontarget species for being a multisite
inhibitor (KEMI, 2015).
The organometallic antifouling biocides such as zinc pyrithione (ZnPT)
and copper pyrithione (CuPT) show microbiocidal activity. There is a lack
of information on the mode of action of pyrithione salts, but it has been
reported that ZnPT and CuPT catalyze the electroneutral exchange of
H+
and other ions with K+
across cell membranes, disrupting the proton
motive force in target organisms. As a consequence, the transport of nutri-
ents across membranes is impaired, leading organisms to starvation and even-
tual death (KEMI, 2014).
Some antifoulants act as broad-spectrum biocides with efficacy against
either weeds or fungi (Fernández-Alba et al., 2002). For instance, the anti-
fouling co-biocide DCOIT (4,5-dichloro-2-octyl-1,2-thiazol-3-one)
reacts with the proteins of fouling specimens when they find the painting
surface, breaking metabolic processes, and hence preventing the attachment
of the organism to solid surfaces. Another important broad-spectrum co-
biocide is TCMTB (1,3-benzothiazol-2-ylsulfanylmethyl thiocyanate) that
inhibits the mitochondrial electron transport chain (Fernández-Alba et al.,
2002) in a wide range of nontarget organisms.
In addition to herbicides, fungicides, microbiocides, and broad-spectrum
biocides, some antifoulants are categorized as “emerging compounds”
because they have a relatively new use as an antifouling biocide encompassing
mainly regional markets. Among them, tralopyril, medetomidine, and TPBP
(pyridine-triphenylborane) should be highlighted as synthetic biocides.
Tralopyril is used in coatings to enhance the antifouling efficacy of
copper-free antifouling paintings by uncoupling mitochondrial oxidative
phosphorylation (EU, 2014; International, 2014). Medetomidine acts
through the activation of analogous octopamine leading to an anti-settling
effect (EU, 2015) and is designed to protect against shell-building marine
organisms. TPBP has been largely used in Japan (Mochida et al., 2012),
but its mode of action is still unknown (Wendt et al., 2016). Capsaicin is a
natural co-biocide extracted from chili peppers, which acts on the nervous
system and also disrupts metabolism and damages membranes (Gervais
et al., 2008). The capsaicin derivative nonivamide acts the same way.
29
Antifoulants and disinfectants
3.3.2 Disinfectants
Formaldehyde is one of the most applied disinfectants in intensive aquacul-
ture, being frequently used to control parasitic infections on fish and crus-
tacean surfaces, and it is also used for treatment against water mold (fungus)
on fish eggs (Boyd and Massaut, 1999). Although its use is encouraged in
hatcheries to control the presence of “fungus,” it is not recommended for
ponds because it kills algae present in pond water, reducing the production
of oxygen by phytoplankton and augmenting the organic matter and
decomposition (Francis-Floyd and Pouder, 1996). Formaldehyde when
diluted in water form is known as formalin. Formalin may be applied as a
prophylactic measure or for therapeutic purposes and is extremely effective
against most protozoan parasites (Ichthyophthirius spp., Costia spp., Epistylis
spp., Chilodonella spp., Scyphidia sp., and Trichodina spp.) and monogenetic
trematodes (Cleidodiscus spp., Gyrodactylus spp., and Dactylogyrus spp.)
(FDA, 1995; Francis-Floyd and Pouder, 1996; Shao, 2001). Due to its elec-
trophilic character, formalin can react with functional groups of several bio-
logical macromolecules, such as proteins, DNA and RNA, polysaccharides,
and glycoproteins (Leal et al., 2018).
Hydrogen peroxide (H2O2) and chlorine are potent oxidizing agents not
only used as broad-spectrum disinfectants in finfish and shellfish produc-
tions, but can also be used to treat fungal infections and as pesticides during
the pond preparation between production cycles (Rico et al., 2012). Chlo-
rine gas and powdered forms such as calcium hypochlorite and sodium
hypochlorite are used to disinfect water supplies in fish and shrimp hatch-
eries. They can be used in ponds after physical sediment removal, also
between production cycles (AQUAVETPLAN, 2008). The chlorine and
H2O2 oxidize electrons from susceptible chemical groups and become
themselves reduced in the process. Oxidizing agents are usually low-molec-
ular-weight compounds ready to easily pass through cell walls/membranes
and then react with internal cellular components disrupting them, and lead-
ing to apoptotic and necrotic cell death (Finnegan et al., 2010). At cellular
level, low levels of oxidation can be reversible and prokaryotic organisms
have developed many defenses against these effects. Recently, Pedersen
et al. (2019) showed a relation between H2O2 decomposition and
particle-associated bacterial activity, suggesting that the quantification of
H2O2 in water samples can be used as a rapid and feasible indicator of micro-
bial activity in fresh and saltwater aquaculture systems, ranging from pond
farming to intensive recirculating systems.
30 Samantha Eslava Martins and Camila de Martinez Gaspar Martins
Iodophors are polyvinylpyrrolidone-iodide-iodine complexes in aque-
ous solution, used as disinfectants for nonhardened fish eggs to prevent
spreading pathogens from the broodstock fish to the offspring
(Lahnsteiner and Kletzl, 2016). Iodine acts by decreasing the oxygen
requirements of aerobic microorganisms. It acts on microorganisms’ respi-
ratory chain by blocking the transport of electrons through electrophilic
reactions with the enzymes of the respiratory chain (Maris, 1995). The opti-
mum concentration is 200mgL1
free iodine with a contact time of 2min
and 100mgL1
free iodine for cleaned and dried equipment. In a nonfood-
contact application, the concentration may rise to 500–800mgL1
. Iodo-
phors should be used with caution because they are highly toxic to fish
(Boyd and Massaut, 1999).
Ammonia treatment in sanitation is a relatively new approach. In contrast
to oxidants, ammonia is not consumed during the treatment. The ammonia
effect on sanitation is sustained for prolonged periods, while also reducing
the risk for regrowth (Kohn et al., 2017). Quaternary ammonium com-
pounds (QACs) impair membrane permeability by irreversibly binding to
phospholipids and proteins of the membrane. One of the commonly used
products is benzalkonium chloride, applied to inhibit bacterial growth
and the development of mucus in the gills of salmon (Burka et al., 1997),
thereby allowing an adequate absorption of oxygen. The capability of the
bacterial cell to absorb such molecules influences sensitivity. These com-
pounds are used in finfish and shellfish production to treat bacterial, proto-
zoan, and monogenean infections and as fungicides in shrimp hatcheries
(Rico et al., 2012).
Ozone is a powerful oxidizing agent widely used in aquaculture for dis-
infection of pathogens and for water quality enhancements since it oxidizes
organic wastes and nitrite. The oxidation of pathogens and other material by
ozone occurs extremely rapidly, through reactions of molecular ozone with
oxidizable compounds, and also due to the reaction of the oxidizable com-
pounds with reactive oxygen species (ROS) formed by ozone decomposi-
tion in water (AQUAVETPLAN, 2008; Gonçalvez and Gagnon, 2011;
Scarfe et al., 2006; Spiliotopoulou et al., 2018; Summerfelt and
Hochheimer, 1997; Tyrell et al., 1995). As an oxidative disinfectant, it is
consumed by organic matter; thus, initial ozone concentration decays faster
in waters with higher concentrations of organic matter as wastewater. For
this reason, it is important to apply an ozone dose that remains in the system
for enough time for the oxidation demands, whether inactivation of path-
ogens or degradation of the organic matter present, without affecting farmed
31
Antifoulants and disinfectants
species. Nevertheless, monitoring ozone performance is still a challenge
(Spiliotopoulou et al., 2018). Ozonation is usually used in recirculating cul-
ture systems that consume less water per kg of fish produced and allow solid
removal and effluent treatment (Gonçalvez and Gagnon, 2011). The liter-
ature reports a wide range of ozone dosages in recirculating systems,
according to the number of animals and feed ratio (Bullock et al., 1997;
Summerfelt et al., 2009; Summerfelt and Hochheimer, 1997). A drawback
of ozone use is that its application is energy-consuming and requires a trained
operator. Even though ozone is more reactive than chlorine in demand-free
solutions toward all microorganisms, it has shown to be more efficient
against viruses, but less efficient against bacteria than chlorine (Tyrell
et al., 1995), although both can inactivate bacterial spores, depending on
the conditions of the application and the origin of the pathogen
(Broadwater et al., 1973; Rose et al., 2005; Tyrell et al., 1995).
Nanomaterials are gaining space as disinfectants for aquaculture pur-
poses. For example, they have been used to improve water quality in shrimp
aquaculture, reducing the rate of water exchange, increasing shrimp survival
rate and yield (Wen et al., 2003). Silver (Ag) nanoparticles (NPs) (nAg) are
the most investigated antibacterial compounds. The nAg was used for the
treatment of fungal infections in rainbow trout eggs showing an inhibitory
effect on fungi growth ( Johari et al., 2015). Dananjaya et al. (2016) inves-
tigated the antibacterial function of chitosan-Ag nanocomposites (CagNCs)
against the fish pathogen Aliivibrio salmonicida. The CagNCs inhibited A. sal-
monicida growth with a minimum inhibitory concentration (MIC) and min-
imum bactericidal concentration (MBC) at 50 and 100mgL1
, respectively.
Similarly, nZnO exhibited antibacterial activity disrupting bacterial cell
membrane integrity, reducing cell surface hydrophobicity and down-
regulating the transcription of oxidative stress-resistance genes (Pati et al.,
2014). Furthermore, M€
uhling et al. (2009) showed that nTiO2 and nAg
reduced the buildup of bacteria in estuarine water ().
Another disinfectant that has been recognized to be suitable for aquacul-
ture is peracetic acid (PAA) which is considered an alternative sanitizer to
formaldehyde. PAA is a highly reactive peroxygen with widespread antimi-
crobial effects (Liu et al., 2015, 2016; Pedersen et al., 2009, 2013). It
degrades entirely within several hours after application, resulting in trace
concentration residuals that are not readily measured (Pedersen et al.,
2009). The test kits are not sensitive enough to analyze PAA at low ranges
(below 0.2ppm). Only a few studies have described analytical measurement
of the commercial PAA compound (Pedersen et al., 2013). In this sense,
32 Samantha Eslava Martins and Camila de Martinez Gaspar Martins
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology
Aquaculture Toxicology

More Related Content

Similar to Aquaculture Toxicology

Selection of Biological Methods for Industrial Effluents Assessments
Selection of Biological Methods for Industrial Effluents AssessmentsSelection of Biological Methods for Industrial Effluents Assessments
Selection of Biological Methods for Industrial Effluents Assessments
Global Risk Forum GRFDavos
 
Present status of aqua-medicines used in aquaculture at Jessore sadar upazila...
Present status of aqua-medicines used in aquaculture at Jessore sadar upazila...Present status of aqua-medicines used in aquaculture at Jessore sadar upazila...
Present status of aqua-medicines used in aquaculture at Jessore sadar upazila...
AbdullaAlAsif1
 
garp-tz_situation_analysis
garp-tz_situation_analysisgarp-tz_situation_analysis
garp-tz_situation_analysis
Saba Danawala
 
howardk_resume_Dec 2015
howardk_resume_Dec 2015howardk_resume_Dec 2015
howardk_resume_Dec 2015
Karen Howard
 
Introducing Bangladesh-2017- rafiquel islam-uon_australia
Introducing Bangladesh-2017- rafiquel islam-uon_australiaIntroducing Bangladesh-2017- rafiquel islam-uon_australia
Introducing Bangladesh-2017- rafiquel islam-uon_australia
Assistant Professor, Dept of ACCT, Islamic University, Kushtia, Bangladesh
 
Brianna_Mellen_Resume
Brianna_Mellen_ResumeBrianna_Mellen_Resume
Brianna_Mellen_Resume
Brianna Mellen
 
MDI Biological Laboratory Arsenic Summit Future Search Results
MDI Biological Laboratory Arsenic Summit Future Search ResultsMDI Biological Laboratory Arsenic Summit Future Search Results
MDI Biological Laboratory Arsenic Summit Future Search Results
vaxelrod
 
Antileishmanial activity and cytotoxicity of brazilian plants
Antileishmanial activity and cytotoxicity of brazilian plantsAntileishmanial activity and cytotoxicity of brazilian plants
Antileishmanial activity and cytotoxicity of brazilian plants
Michele Soares de Lima
 
men12140
men12140men12140
Pesticide Handbook
Pesticide HandbookPesticide Handbook
Pesticide Handbook
kk 555888
 
FAS-Online Abstracts 2015
FAS-Online Abstracts 2015FAS-Online Abstracts 2015
FAS-Online Abstracts 2015
Reginald Brown
 
qPCR_USA_agenda
qPCR_USA_agendaqPCR_USA_agenda
qPCR_USA_agenda
Nick Best
 
Aquaculture microbiology and biotechnology vol (1)
Aquaculture microbiology and biotechnology vol  (1)Aquaculture microbiology and biotechnology vol  (1)
Aquaculture microbiology and biotechnology vol (1)
أسعد لحمر
 
Short Communication: Natural Prophylaxis to the Control of Swine Coccidiosis
Short Communication: Natural Prophylaxis to the Control of Swine CoccidiosisShort Communication: Natural Prophylaxis to the Control of Swine Coccidiosis
Short Communication: Natural Prophylaxis to the Control of Swine Coccidiosis
Agriculture Journal IJOEAR
 
Microbiome Probiotics Asia Agenda
Microbiome Probiotics Asia AgendaMicrobiome Probiotics Asia Agenda
Microbiome Probiotics Asia Agenda
Maxime L
 
Thameem.Rajamohamedsait-INDIA-2015
Thameem.Rajamohamedsait-INDIA-2015Thameem.Rajamohamedsait-INDIA-2015
Thameem.Rajamohamedsait-INDIA-2015
Thameem Azarudeen
 
Treatment of Pesticide Poisoning
Treatment of Pesticide PoisoningTreatment of Pesticide Poisoning
Treatment of Pesticide Poisoning
Z3P
 
Making Decisions about the Risks of Chemicals in Foods with Limited Scientifi...
Making Decisions about the Risks of Chemicals in Foods with Limited Scientifi...Making Decisions about the Risks of Chemicals in Foods with Limited Scientifi...
Making Decisions about the Risks of Chemicals in Foods with Limited Scientifi...
Coughlin & Associates: Consultants in Food/Nutritional/Chemical Toxicology & Safety
 
CV-Ingles-2016
CV-Ingles-2016CV-Ingles-2016
CV-Ingles-2016
Abraham Vaisberg
 
Analysis of wastewater for use in agriculture a laboratory manual of parasito...
Analysis of wastewater for use in agriculture a laboratory manual of parasito...Analysis of wastewater for use in agriculture a laboratory manual of parasito...
Analysis of wastewater for use in agriculture a laboratory manual of parasito...
Wal Elsis
 

Similar to Aquaculture Toxicology (20)

Selection of Biological Methods for Industrial Effluents Assessments
Selection of Biological Methods for Industrial Effluents AssessmentsSelection of Biological Methods for Industrial Effluents Assessments
Selection of Biological Methods for Industrial Effluents Assessments
 
Present status of aqua-medicines used in aquaculture at Jessore sadar upazila...
Present status of aqua-medicines used in aquaculture at Jessore sadar upazila...Present status of aqua-medicines used in aquaculture at Jessore sadar upazila...
Present status of aqua-medicines used in aquaculture at Jessore sadar upazila...
 
garp-tz_situation_analysis
garp-tz_situation_analysisgarp-tz_situation_analysis
garp-tz_situation_analysis
 
howardk_resume_Dec 2015
howardk_resume_Dec 2015howardk_resume_Dec 2015
howardk_resume_Dec 2015
 
Introducing Bangladesh-2017- rafiquel islam-uon_australia
Introducing Bangladesh-2017- rafiquel islam-uon_australiaIntroducing Bangladesh-2017- rafiquel islam-uon_australia
Introducing Bangladesh-2017- rafiquel islam-uon_australia
 
Brianna_Mellen_Resume
Brianna_Mellen_ResumeBrianna_Mellen_Resume
Brianna_Mellen_Resume
 
MDI Biological Laboratory Arsenic Summit Future Search Results
MDI Biological Laboratory Arsenic Summit Future Search ResultsMDI Biological Laboratory Arsenic Summit Future Search Results
MDI Biological Laboratory Arsenic Summit Future Search Results
 
Antileishmanial activity and cytotoxicity of brazilian plants
Antileishmanial activity and cytotoxicity of brazilian plantsAntileishmanial activity and cytotoxicity of brazilian plants
Antileishmanial activity and cytotoxicity of brazilian plants
 
men12140
men12140men12140
men12140
 
Pesticide Handbook
Pesticide HandbookPesticide Handbook
Pesticide Handbook
 
FAS-Online Abstracts 2015
FAS-Online Abstracts 2015FAS-Online Abstracts 2015
FAS-Online Abstracts 2015
 
qPCR_USA_agenda
qPCR_USA_agendaqPCR_USA_agenda
qPCR_USA_agenda
 
Aquaculture microbiology and biotechnology vol (1)
Aquaculture microbiology and biotechnology vol  (1)Aquaculture microbiology and biotechnology vol  (1)
Aquaculture microbiology and biotechnology vol (1)
 
Short Communication: Natural Prophylaxis to the Control of Swine Coccidiosis
Short Communication: Natural Prophylaxis to the Control of Swine CoccidiosisShort Communication: Natural Prophylaxis to the Control of Swine Coccidiosis
Short Communication: Natural Prophylaxis to the Control of Swine Coccidiosis
 
Microbiome Probiotics Asia Agenda
Microbiome Probiotics Asia AgendaMicrobiome Probiotics Asia Agenda
Microbiome Probiotics Asia Agenda
 
Thameem.Rajamohamedsait-INDIA-2015
Thameem.Rajamohamedsait-INDIA-2015Thameem.Rajamohamedsait-INDIA-2015
Thameem.Rajamohamedsait-INDIA-2015
 
Treatment of Pesticide Poisoning
Treatment of Pesticide PoisoningTreatment of Pesticide Poisoning
Treatment of Pesticide Poisoning
 
Making Decisions about the Risks of Chemicals in Foods with Limited Scientifi...
Making Decisions about the Risks of Chemicals in Foods with Limited Scientifi...Making Decisions about the Risks of Chemicals in Foods with Limited Scientifi...
Making Decisions about the Risks of Chemicals in Foods with Limited Scientifi...
 
CV-Ingles-2016
CV-Ingles-2016CV-Ingles-2016
CV-Ingles-2016
 
Analysis of wastewater for use in agriculture a laboratory manual of parasito...
Analysis of wastewater for use in agriculture a laboratory manual of parasito...Analysis of wastewater for use in agriculture a laboratory manual of parasito...
Analysis of wastewater for use in agriculture a laboratory manual of parasito...
 

More from Wiwin Kusuma Atmaja Putra

Wiwin KusumPhycoremediation bagi Lingkungan Aquaculture.pptx
Wiwin KusumPhycoremediation bagi Lingkungan Aquaculture.pptxWiwin KusumPhycoremediation bagi Lingkungan Aquaculture.pptx
Wiwin KusumPhycoremediation bagi Lingkungan Aquaculture.pptx
Wiwin Kusuma Atmaja Putra
 
sistem Lingkungan akuakultur "Eutrofikasi".pdf
sistem Lingkungan akuakultur "Eutrofikasi".pdfsistem Lingkungan akuakultur "Eutrofikasi".pdf
sistem Lingkungan akuakultur "Eutrofikasi".pdf
Wiwin Kusuma Atmaja Putra
 
EVALUASI KINERJA PRODUKSI DAN RESPONS FISIOLOGIS TERIPANG PASIR dengan MEDIA ...
EVALUASI KINERJA PRODUKSI DAN RESPONS FISIOLOGIS TERIPANG PASIR dengan MEDIA ...EVALUASI KINERJA PRODUKSI DAN RESPONS FISIOLOGIS TERIPANG PASIR dengan MEDIA ...
EVALUASI KINERJA PRODUKSI DAN RESPONS FISIOLOGIS TERIPANG PASIR dengan MEDIA ...
Wiwin Kusuma Atmaja Putra
 
OMICS STRATERGY PADA MANAJEMEN PENYAKIT.pptx
OMICS STRATERGY  PADA MANAJEMEN PENYAKIT.pptxOMICS STRATERGY  PADA MANAJEMEN PENYAKIT.pptx
OMICS STRATERGY PADA MANAJEMEN PENYAKIT.pptx
Wiwin Kusuma Atmaja Putra
 
IMPORT RISK ANALYSIS.pdf
IMPORT RISK ANALYSIS.pdfIMPORT RISK ANALYSIS.pdf
IMPORT RISK ANALYSIS.pdf
Wiwin Kusuma Atmaja Putra
 
Presentasi Evaluasi sumber bahan baku pakan Protein Hewani Maggot.pptx
Presentasi Evaluasi sumber bahan baku pakan Protein Hewani Maggot.pptxPresentasi Evaluasi sumber bahan baku pakan Protein Hewani Maggot.pptx
Presentasi Evaluasi sumber bahan baku pakan Protein Hewani Maggot.pptx
Wiwin Kusuma Atmaja Putra
 
5technical guide line ECOSYSTEM APPROACH TO AQUACULTURE FAO.pdf
5technical guide line  ECOSYSTEM APPROACH TO AQUACULTURE FAO.pdf5technical guide line  ECOSYSTEM APPROACH TO AQUACULTURE FAO.pdf
5technical guide line ECOSYSTEM APPROACH TO AQUACULTURE FAO.pdf
Wiwin Kusuma Atmaja Putra
 
FAO CARRYING CAPACITY Inland LONDON.pdf
FAO CARRYING CAPACITY Inland LONDON.pdfFAO CARRYING CAPACITY Inland LONDON.pdf
FAO CARRYING CAPACITY Inland LONDON.pdf
Wiwin Kusuma Atmaja Putra
 
CARRYING CAPACITY ESTIMATION NITROGEN shrimp culture.pdf
CARRYING CAPACITY ESTIMATION NITROGEN shrimp culture.pdfCARRYING CAPACITY ESTIMATION NITROGEN shrimp culture.pdf
CARRYING CAPACITY ESTIMATION NITROGEN shrimp culture.pdf
Wiwin Kusuma Atmaja Putra
 
The Environmental Impact of Marine Shrimp Farming Effluents.pptx
The Environmental Impact of Marine Shrimp Farming Effluents.pptxThe Environmental Impact of Marine Shrimp Farming Effluents.pptx
The Environmental Impact of Marine Shrimp Farming Effluents.pptx
Wiwin Kusuma Atmaja Putra
 
The Toxicology of Fishes.pdf
The Toxicology of Fishes.pdfThe Toxicology of Fishes.pdf
The Toxicology of Fishes.pdf
Wiwin Kusuma Atmaja Putra
 
EVALUASI SISTEM DAN PENGELOLAAN PENDEDERAN IKAN KERAPU.pdf
EVALUASI SISTEM DAN PENGELOLAAN PENDEDERAN IKAN KERAPU.pdfEVALUASI SISTEM DAN PENGELOLAAN PENDEDERAN IKAN KERAPU.pdf
EVALUASI SISTEM DAN PENGELOLAAN PENDEDERAN IKAN KERAPU.pdf
Wiwin Kusuma Atmaja Putra
 
UAS FISREP AVERTEBRATA AIR.pdf
UAS FISREP AVERTEBRATA AIR.pdfUAS FISREP AVERTEBRATA AIR.pdf
UAS FISREP AVERTEBRATA AIR.pdf
Wiwin Kusuma Atmaja Putra
 
PERAN NUTRISI PADA SISTEM IMUN IKAN .pdf
PERAN NUTRISI PADA SISTEM IMUN IKAN .pdfPERAN NUTRISI PADA SISTEM IMUN IKAN .pdf
PERAN NUTRISI PADA SISTEM IMUN IKAN .pdf
Wiwin Kusuma Atmaja Putra
 
Kinerja Hormon Reproduksi ikan pada matakuliah endokrinologi ikan.pptx
Kinerja Hormon Reproduksi ikan pada matakuliah endokrinologi ikan.pptxKinerja Hormon Reproduksi ikan pada matakuliah endokrinologi ikan.pptx
Kinerja Hormon Reproduksi ikan pada matakuliah endokrinologi ikan.pptx
Wiwin Kusuma Atmaja Putra
 
REPRODUKSI BINTANG LAUT.pdf
REPRODUKSI BINTANG LAUT.pdfREPRODUKSI BINTANG LAUT.pdf
REPRODUKSI BINTANG LAUT.pdf
Wiwin Kusuma Atmaja Putra
 
Stress pada ikan wiwin.pdf
Stress pada ikan wiwin.pdfStress pada ikan wiwin.pdf
Stress pada ikan wiwin.pdf
Wiwin Kusuma Atmaja Putra
 
Buku teknologi tepat guna.pdf
Buku teknologi tepat guna.pdfBuku teknologi tepat guna.pdf
Buku teknologi tepat guna.pdf
Wiwin Kusuma Atmaja Putra
 

More from Wiwin Kusuma Atmaja Putra (18)

Wiwin KusumPhycoremediation bagi Lingkungan Aquaculture.pptx
Wiwin KusumPhycoremediation bagi Lingkungan Aquaculture.pptxWiwin KusumPhycoremediation bagi Lingkungan Aquaculture.pptx
Wiwin KusumPhycoremediation bagi Lingkungan Aquaculture.pptx
 
sistem Lingkungan akuakultur "Eutrofikasi".pdf
sistem Lingkungan akuakultur "Eutrofikasi".pdfsistem Lingkungan akuakultur "Eutrofikasi".pdf
sistem Lingkungan akuakultur "Eutrofikasi".pdf
 
EVALUASI KINERJA PRODUKSI DAN RESPONS FISIOLOGIS TERIPANG PASIR dengan MEDIA ...
EVALUASI KINERJA PRODUKSI DAN RESPONS FISIOLOGIS TERIPANG PASIR dengan MEDIA ...EVALUASI KINERJA PRODUKSI DAN RESPONS FISIOLOGIS TERIPANG PASIR dengan MEDIA ...
EVALUASI KINERJA PRODUKSI DAN RESPONS FISIOLOGIS TERIPANG PASIR dengan MEDIA ...
 
OMICS STRATERGY PADA MANAJEMEN PENYAKIT.pptx
OMICS STRATERGY  PADA MANAJEMEN PENYAKIT.pptxOMICS STRATERGY  PADA MANAJEMEN PENYAKIT.pptx
OMICS STRATERGY PADA MANAJEMEN PENYAKIT.pptx
 
IMPORT RISK ANALYSIS.pdf
IMPORT RISK ANALYSIS.pdfIMPORT RISK ANALYSIS.pdf
IMPORT RISK ANALYSIS.pdf
 
Presentasi Evaluasi sumber bahan baku pakan Protein Hewani Maggot.pptx
Presentasi Evaluasi sumber bahan baku pakan Protein Hewani Maggot.pptxPresentasi Evaluasi sumber bahan baku pakan Protein Hewani Maggot.pptx
Presentasi Evaluasi sumber bahan baku pakan Protein Hewani Maggot.pptx
 
5technical guide line ECOSYSTEM APPROACH TO AQUACULTURE FAO.pdf
5technical guide line  ECOSYSTEM APPROACH TO AQUACULTURE FAO.pdf5technical guide line  ECOSYSTEM APPROACH TO AQUACULTURE FAO.pdf
5technical guide line ECOSYSTEM APPROACH TO AQUACULTURE FAO.pdf
 
FAO CARRYING CAPACITY Inland LONDON.pdf
FAO CARRYING CAPACITY Inland LONDON.pdfFAO CARRYING CAPACITY Inland LONDON.pdf
FAO CARRYING CAPACITY Inland LONDON.pdf
 
CARRYING CAPACITY ESTIMATION NITROGEN shrimp culture.pdf
CARRYING CAPACITY ESTIMATION NITROGEN shrimp culture.pdfCARRYING CAPACITY ESTIMATION NITROGEN shrimp culture.pdf
CARRYING CAPACITY ESTIMATION NITROGEN shrimp culture.pdf
 
The Environmental Impact of Marine Shrimp Farming Effluents.pptx
The Environmental Impact of Marine Shrimp Farming Effluents.pptxThe Environmental Impact of Marine Shrimp Farming Effluents.pptx
The Environmental Impact of Marine Shrimp Farming Effluents.pptx
 
The Toxicology of Fishes.pdf
The Toxicology of Fishes.pdfThe Toxicology of Fishes.pdf
The Toxicology of Fishes.pdf
 
EVALUASI SISTEM DAN PENGELOLAAN PENDEDERAN IKAN KERAPU.pdf
EVALUASI SISTEM DAN PENGELOLAAN PENDEDERAN IKAN KERAPU.pdfEVALUASI SISTEM DAN PENGELOLAAN PENDEDERAN IKAN KERAPU.pdf
EVALUASI SISTEM DAN PENGELOLAAN PENDEDERAN IKAN KERAPU.pdf
 
UAS FISREP AVERTEBRATA AIR.pdf
UAS FISREP AVERTEBRATA AIR.pdfUAS FISREP AVERTEBRATA AIR.pdf
UAS FISREP AVERTEBRATA AIR.pdf
 
PERAN NUTRISI PADA SISTEM IMUN IKAN .pdf
PERAN NUTRISI PADA SISTEM IMUN IKAN .pdfPERAN NUTRISI PADA SISTEM IMUN IKAN .pdf
PERAN NUTRISI PADA SISTEM IMUN IKAN .pdf
 
Kinerja Hormon Reproduksi ikan pada matakuliah endokrinologi ikan.pptx
Kinerja Hormon Reproduksi ikan pada matakuliah endokrinologi ikan.pptxKinerja Hormon Reproduksi ikan pada matakuliah endokrinologi ikan.pptx
Kinerja Hormon Reproduksi ikan pada matakuliah endokrinologi ikan.pptx
 
REPRODUKSI BINTANG LAUT.pdf
REPRODUKSI BINTANG LAUT.pdfREPRODUKSI BINTANG LAUT.pdf
REPRODUKSI BINTANG LAUT.pdf
 
Stress pada ikan wiwin.pdf
Stress pada ikan wiwin.pdfStress pada ikan wiwin.pdf
Stress pada ikan wiwin.pdf
 
Buku teknologi tepat guna.pdf
Buku teknologi tepat guna.pdfBuku teknologi tepat guna.pdf
Buku teknologi tepat guna.pdf
 

Recently uploaded

NuGOweek 2024 Ghent programme__flyer.pdf
NuGOweek 2024 Ghent programme__flyer.pdfNuGOweek 2024 Ghent programme__flyer.pdf
NuGOweek 2024 Ghent programme__flyer.pdf
pablovgd
 
17. 20240529_Ingrid Olesen_MariGreen summer school.pdf
17. 20240529_Ingrid Olesen_MariGreen summer school.pdf17. 20240529_Ingrid Olesen_MariGreen summer school.pdf
17. 20240529_Ingrid Olesen_MariGreen summer school.pdf
marigreenproject
 
Phytoremediation: Harnessing Nature's Power with Phytoremediation
Phytoremediation: Harnessing Nature's Power with PhytoremediationPhytoremediation: Harnessing Nature's Power with Phytoremediation
Phytoremediation: Harnessing Nature's Power with Phytoremediation
Gurjant Singh
 
Introduction to Space (Our Solar System)
Introduction to Space (Our Solar System)Introduction to Space (Our Solar System)
Introduction to Space (Our Solar System)
vanshgarg8002
 
Review Article:- A REVIEW ON RADIOISOTOPES IN CANCER THERAPY
Review Article:- A REVIEW ON RADIOISOTOPES IN CANCER THERAPYReview Article:- A REVIEW ON RADIOISOTOPES IN CANCER THERAPY
Review Article:- A REVIEW ON RADIOISOTOPES IN CANCER THERAPY
niranjangiri009
 
Ancient Theory, Abiogenesis , Biogenesis
Ancient Theory, Abiogenesis , BiogenesisAncient Theory, Abiogenesis , Biogenesis
Ancient Theory, Abiogenesis , Biogenesis
SoniaBajaj10
 
Fish in the Loop: Exploring RAS - Julie Hansen Bergstedt
Fish in the Loop: Exploring RAS - Julie Hansen BergstedtFish in the Loop: Exploring RAS - Julie Hansen Bergstedt
Fish in the Loop: Exploring RAS - Julie Hansen Bergstedt
Faculty of Applied Chemistry and Materials Science
 
atom, elements, molecule and compounds in telugu.pptx
atom, elements, molecule and compounds in telugu.pptxatom, elements, molecule and compounds in telugu.pptx
atom, elements, molecule and compounds in telugu.pptx
ManjulaVani3
 
Pancreas_functional anatomy_enzymes.pptx
Pancreas_functional anatomy_enzymes.pptxPancreas_functional anatomy_enzymes.pptx
Pancreas_functional anatomy_enzymes.pptx
muralinath2
 
Adjusted NuGOweek 2024 Ghent programme flyer
Adjusted NuGOweek 2024 Ghent programme flyerAdjusted NuGOweek 2024 Ghent programme flyer
Adjusted NuGOweek 2024 Ghent programme flyer
pablovgd
 
AlgaeBrew project - Unlocking the potential of microalgae for the valorisatio...
AlgaeBrew project - Unlocking the potential of microalgae for the valorisatio...AlgaeBrew project - Unlocking the potential of microalgae for the valorisatio...
AlgaeBrew project - Unlocking the potential of microalgae for the valorisatio...
Faculty of Applied Chemistry and Materials Science
 
Complementary interstellar detections from the heliotail
Complementary interstellar detections from the heliotailComplementary interstellar detections from the heliotail
Complementary interstellar detections from the heliotail
Sérgio Sacani
 
Potential of Marine renewable and Non renewable energy.pptx
Potential of Marine renewable and Non renewable energy.pptxPotential of Marine renewable and Non renewable energy.pptx
Potential of Marine renewable and Non renewable energy.pptx
J. Bovas Joel BFSc
 
A Strong He II λ1640 Emitter with an Extremely Blue UV Spectral Slope at z=8....
A Strong He II λ1640 Emitter with an Extremely Blue UV Spectral Slope at z=8....A Strong He II λ1640 Emitter with an Extremely Blue UV Spectral Slope at z=8....
A Strong He II λ1640 Emitter with an Extremely Blue UV Spectral Slope at z=8....
Sérgio Sacani
 
Detection of the elusive dangling OH ice features at ~2.7 μm in Chamaeleon I ...
Detection of the elusive dangling OH ice features at ~2.7 μm in Chamaeleon I ...Detection of the elusive dangling OH ice features at ~2.7 μm in Chamaeleon I ...
Detection of the elusive dangling OH ice features at ~2.7 μm in Chamaeleon I ...
Sérgio Sacani
 
Structure of Sperm / Spermatozoon .pdf
Structure of  Sperm / Spermatozoon  .pdfStructure of  Sperm / Spermatozoon  .pdf
Structure of Sperm / Spermatozoon .pdf
SELF-EXPLANATORY
 
Post RN - Biochemistry (Unit 7) Metabolism
Post RN - Biochemistry (Unit 7) MetabolismPost RN - Biochemistry (Unit 7) Metabolism
Post RN - Biochemistry (Unit 7) Metabolism
Areesha Ahmad
 
Lake classification and Morphometry.pptx
Lake classification and Morphometry.pptxLake classification and Morphometry.pptx
Lake classification and Morphometry.pptx
boobalanbfsc
 
Surface properties of the seas of Titan as revealed by Cassini mission bistat...
Surface properties of the seas of Titan as revealed by Cassini mission bistat...Surface properties of the seas of Titan as revealed by Cassini mission bistat...
Surface properties of the seas of Titan as revealed by Cassini mission bistat...
Sérgio Sacani
 
bloodclotfactorsprocoagulantsexstrinsicintrinsicfactors-240607054610-6895d6e5...
bloodclotfactorsprocoagulantsexstrinsicintrinsicfactors-240607054610-6895d6e5...bloodclotfactorsprocoagulantsexstrinsicintrinsicfactors-240607054610-6895d6e5...
bloodclotfactorsprocoagulantsexstrinsicintrinsicfactors-240607054610-6895d6e5...
muralinath2
 

Recently uploaded (20)

NuGOweek 2024 Ghent programme__flyer.pdf
NuGOweek 2024 Ghent programme__flyer.pdfNuGOweek 2024 Ghent programme__flyer.pdf
NuGOweek 2024 Ghent programme__flyer.pdf
 
17. 20240529_Ingrid Olesen_MariGreen summer school.pdf
17. 20240529_Ingrid Olesen_MariGreen summer school.pdf17. 20240529_Ingrid Olesen_MariGreen summer school.pdf
17. 20240529_Ingrid Olesen_MariGreen summer school.pdf
 
Phytoremediation: Harnessing Nature's Power with Phytoremediation
Phytoremediation: Harnessing Nature's Power with PhytoremediationPhytoremediation: Harnessing Nature's Power with Phytoremediation
Phytoremediation: Harnessing Nature's Power with Phytoremediation
 
Introduction to Space (Our Solar System)
Introduction to Space (Our Solar System)Introduction to Space (Our Solar System)
Introduction to Space (Our Solar System)
 
Review Article:- A REVIEW ON RADIOISOTOPES IN CANCER THERAPY
Review Article:- A REVIEW ON RADIOISOTOPES IN CANCER THERAPYReview Article:- A REVIEW ON RADIOISOTOPES IN CANCER THERAPY
Review Article:- A REVIEW ON RADIOISOTOPES IN CANCER THERAPY
 
Ancient Theory, Abiogenesis , Biogenesis
Ancient Theory, Abiogenesis , BiogenesisAncient Theory, Abiogenesis , Biogenesis
Ancient Theory, Abiogenesis , Biogenesis
 
Fish in the Loop: Exploring RAS - Julie Hansen Bergstedt
Fish in the Loop: Exploring RAS - Julie Hansen BergstedtFish in the Loop: Exploring RAS - Julie Hansen Bergstedt
Fish in the Loop: Exploring RAS - Julie Hansen Bergstedt
 
atom, elements, molecule and compounds in telugu.pptx
atom, elements, molecule and compounds in telugu.pptxatom, elements, molecule and compounds in telugu.pptx
atom, elements, molecule and compounds in telugu.pptx
 
Pancreas_functional anatomy_enzymes.pptx
Pancreas_functional anatomy_enzymes.pptxPancreas_functional anatomy_enzymes.pptx
Pancreas_functional anatomy_enzymes.pptx
 
Adjusted NuGOweek 2024 Ghent programme flyer
Adjusted NuGOweek 2024 Ghent programme flyerAdjusted NuGOweek 2024 Ghent programme flyer
Adjusted NuGOweek 2024 Ghent programme flyer
 
AlgaeBrew project - Unlocking the potential of microalgae for the valorisatio...
AlgaeBrew project - Unlocking the potential of microalgae for the valorisatio...AlgaeBrew project - Unlocking the potential of microalgae for the valorisatio...
AlgaeBrew project - Unlocking the potential of microalgae for the valorisatio...
 
Complementary interstellar detections from the heliotail
Complementary interstellar detections from the heliotailComplementary interstellar detections from the heliotail
Complementary interstellar detections from the heliotail
 
Potential of Marine renewable and Non renewable energy.pptx
Potential of Marine renewable and Non renewable energy.pptxPotential of Marine renewable and Non renewable energy.pptx
Potential of Marine renewable and Non renewable energy.pptx
 
A Strong He II λ1640 Emitter with an Extremely Blue UV Spectral Slope at z=8....
A Strong He II λ1640 Emitter with an Extremely Blue UV Spectral Slope at z=8....A Strong He II λ1640 Emitter with an Extremely Blue UV Spectral Slope at z=8....
A Strong He II λ1640 Emitter with an Extremely Blue UV Spectral Slope at z=8....
 
Detection of the elusive dangling OH ice features at ~2.7 μm in Chamaeleon I ...
Detection of the elusive dangling OH ice features at ~2.7 μm in Chamaeleon I ...Detection of the elusive dangling OH ice features at ~2.7 μm in Chamaeleon I ...
Detection of the elusive dangling OH ice features at ~2.7 μm in Chamaeleon I ...
 
Structure of Sperm / Spermatozoon .pdf
Structure of  Sperm / Spermatozoon  .pdfStructure of  Sperm / Spermatozoon  .pdf
Structure of Sperm / Spermatozoon .pdf
 
Post RN - Biochemistry (Unit 7) Metabolism
Post RN - Biochemistry (Unit 7) MetabolismPost RN - Biochemistry (Unit 7) Metabolism
Post RN - Biochemistry (Unit 7) Metabolism
 
Lake classification and Morphometry.pptx
Lake classification and Morphometry.pptxLake classification and Morphometry.pptx
Lake classification and Morphometry.pptx
 
Surface properties of the seas of Titan as revealed by Cassini mission bistat...
Surface properties of the seas of Titan as revealed by Cassini mission bistat...Surface properties of the seas of Titan as revealed by Cassini mission bistat...
Surface properties of the seas of Titan as revealed by Cassini mission bistat...
 
bloodclotfactorsprocoagulantsexstrinsicintrinsicfactors-240607054610-6895d6e5...
bloodclotfactorsprocoagulantsexstrinsicintrinsicfactors-240607054610-6895d6e5...bloodclotfactorsprocoagulantsexstrinsicintrinsicfactors-240607054610-6895d6e5...
bloodclotfactorsprocoagulantsexstrinsicintrinsicfactors-240607054610-6895d6e5...
 

Aquaculture Toxicology

  • 4. AQUACULTURE TOXICOLOGY Edited by FREDERICK S.B. KIBENGE Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada BERNARDO BALDISSEROTTO Full Professor, Department of Physiology and Pharmacology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil ROGER SIE-MAEN CHONG Registered Veterinary Specialist of Fish Health and Production, Royal College of Veterinary Surgeons, London, United Kingdom Registered Specialist of Veterinary Aquatic Animal Health, Queensland Veterinary Surgeons Board; Senior Veterinarian (Aquatic Pathology) Biosecurity Sciences Laboratory, QLD, Australia Current affiliation: Australian Commonwealth Scientific Industrial Research Organization (CSIRO), Brisbane, QLD, Australia
  • 5. Academic Press is an imprint of Elsevier 125 London Wall, London EC2Y 5AS, United Kingdom 525 B Street, Suite 1650, San Diego, CA 92101, United States 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom © 2021 Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library ISBN 978-0-12-821337-7 For information on all Academic Press publications visit our website at https://www.elsevier.com/books-and-journals Publisher: Mica Haley Acquisitions Editor: Patricia Osborn Editorial Project Manager: Billie Jean Fernandez Production Project Manager: Maria Bernard Cover Designer: Greg Harris Typeset by SPi Global, India
  • 6. Contents Contributors ix About the editors xi Preface xiii 1. Introduction to aquaculture 1 Frederick S.B. Kibenge 1.1 Introduction 1 1.2 Structure of the global aquaculture industry 2 1.3 Mollusk aquaculture 9 1.4 Crustacean aquaculture 10 1.5 Chemicals in aquaculture 10 1.6 Governance of aquaculture 11 References 12 2. General introduction to toxicology of aquatic animals 17 Bernardo Baldisserotto 2.1 Introduction to toxicology 17 2.2 Water quality criteria/guidelines 18 2.3 Intraspecies variation of toxicity 20 2.4 Models to predict toxicity of contaminants 21 References 22 3. Antifoulants and disinfectants 25 Samantha Eslava Martins and Camila de Martinez Gaspar Martins 3.1 Overview 25 3.2 Definitions and uses 26 3.3 Mode of action 28 3.4 Ecotoxicity and biological effects 33 3.5 Ecological risks and regulation 46 3.6 Further considerations 49 References 50 v
  • 7. 4. Metals 59 Claudia B.R. Martinez, Juliana D. Simonato Rocha, and Paulo Cesar Meletti 4.1 Introduction 59 4.2 Biochemical effects 62 4.3 Physiological effects 67 4.4 Behavioral effects 69 References 73 5. Agrochemicals: Ecotoxicology and management in aquaculture 79 Vania Lucia Loro and Bárbara Estevão Clasen 5.1 Water and soil contamination by agrochemicals 79 5.2 Environmental contamination by agrochemicals and risk assessment in aquaculture: Effects on aquatic organisms and food for human consumption 82 5.3 Mitigation of agrochemicals 94 5.4 Agrochemicals banned from use in agriculture and aquaculture 98 5.5 Regulatory process for new chemicals and good agricultural practices 98 References 101 6. Pharmaceutical pollutants 107 Helena Cristina Silva de Assis 6.1 Introduction 107 6.2 Pharmaceuticals in the aquatic environment 108 6.3 Pharmaceutical sources and pathway to the environment 109 6.4 Pharmaceutical exposure effects in nontarget species 111 6.5 Final considerations 123 References 124 7. Oil and derivatives 133 Helen Sadauskas-Henrique, Luciana Rodrigues Souza-Bastos, and Grazyelle Sebrenski Silva 7.1 Oil and derivatives and the aquatic contamination 133 7.2 Aquaculture and the problem of oil and derivative contamination 137 vi Contents
  • 8. 7.3 Effects of oil and derivatives on fish species 140 7.4 Effects of oil and derivatives on mollusks and crustaceans 160 7.5 Interaction of oil and derivatives with water characteristics 169 7.6 Future perspectives on oil and derivative contamination and aquaculture 172 References 173 8. Ecotoxicological effects of microplastics and associated pollutants 189 Fábio Vieira de Araújo, Rebeca Oliveira Castro, Melanie Lopes da Silva, and Mariana Muniz Silva 8.1 Introduction 189 8.2 Impacts of microplastic on marine animals 190 8.3 Plastic additives 191 8.4 Microplastic and persistent organic pollutants (POPs) 195 8.5 Microplastics and metals 203 8.6 Microplastics and microorganisms: The plastisphere 205 8.7 Microplastics and other compounds 213 8.8 Final considerations 214 References 216 Index 229 vii Contents
  • 10. Contributors Bernardo Baldisserotto Department of Physiology and Pharmacology, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil Bárbara Estevão Clasen Department of Environmental Sciences, State University of Rio Grande do Sul, Tr^ es Passos, RS, Brazil Rebeca Oliveira Castro Programa de Pós Graduação em Biologia Marinha e Ambientes Costeiros, Universidade Federal Fluminense, Niterói, RJ, Brazil Camila de Martinez Gaspar Martins Universidade Federal do Rio Grande—FURG, Instituto de Ci^ encias Biológicas, Rio Grande/RS, Brazil Fábio Vieira de Araújo Faculdade de Formação de Professores, Universidade do Estado do Rio de Janeiro, São Gonçalo, RJ, Brazil Grazyelle Sebrenski Silva Departamento de Morfologia, Universidade Federal do Amazonas (UFAM), Manaus, Brazil Luciana Rodrigues Souza-Bastos Instituto de Tecnologia para o Desenvolvimento (LACTEC), Laboratório de Toxicologia e Avaliação Ambiental, Ambiental, Curitiba, Brazil Mariana Muniz Silva Programa de Pós Graduação em Biologia Marinha e Ambientes Costeiros, Universidade Federal Fluminense, Niterói, RJ, Brazil Melanie Lopes da Silva Laboratório de Ecologia e Din^ amica B^ entica Marinha, Faculdade de Formação de Professores, Universidade do Estado do Rio de Janeiro, São Gonçalo, RJ, Brazil Frederick S.B. Kibenge Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada Vania Lucia Loro Laboratory of Aquatic Toxicology, Department of Biochemistry and Molecular Biology, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil Paulo Cesar Meletti Laboratory of Animal Ecophysiology, Department of Physiological Sciences, State University of Londrina, Londrina, Parana, Brazil Claudia B.R. Martinez Laboratory of Animal Ecophysiology, Department of Physiological Sciences, State University of Londrina, Londrina, Parana, Brazil Samantha Eslava Martins Norwegian Institute for Water Research (NIVA), Ecotoxicology and Risk Assessment Section, Oslo, Norway; Universidade Federal do Rio Grande—FURG, Instituto de Ci^ encias Biológicas, Rio Grande/RS, Brazil Helena Cristina Silva de Assis Department of Pharmacology, Federal University of Paraná, Curitiba, Paraná, Brazil ix
  • 11. Helen Sadauskas-Henrique Universidade Santa Cecı́lia (Unisanta), Laboratório de Biologia de Organismos Marinhos e Costeiros (LABOMAC), Santos, Brazil Juliana D. Simonato Rocha Laboratory of Animal Ecophysiology, Department of Physiological Sciences, State University of Londrina, Londrina, Parana, Brazil x Contributors
  • 12. About the editors Dr. Frederick S.B. Kibenge is Professor of Virology at the Atlantic Vet- erinary College, University of Prince Edward Island, Charlottetown, PEI, Canada, where he has been Chairman of the Department of Pathology and Microbiology for several years, and teaches veterinary virology in the second year of the DVM curriculum. He has been working with animal viruses for more than 30years in addition to prior extensive postdoc- toral research experience in virology in the United Kingdom and the United States. He is a Diplomate of the American College of Veterinary Microbiol- ogists, ACVM (subspecialty Immunology). He has published extensively on the detection and virology of fish viruses. He is editor of the accompanying two textbooks on the theme of aquaculture: Aquaculture Pathophysiology and Aquaculture Pharmacology published by Elsevier Inc., Academic Press. Dr. Bernardo Baldisserotto is a full Professor of Physiology of the Departamento de Fisiologia e Farmacologia at the Universidade Federal de Santa Maria, in South Brazil. He supervises graduate students from the programs of Animal Husbandry, Pharmacology, and Animal Biodiversity at this university and has published several articles dealing with toxicology of aquatic animals, mainly fish. He is the coauthor on some of the book chapters and has published a book regarding Pharmacology applied to aqua- culture (in Portuguese). He is editor of the accompanying two textbooks on the theme of aquaculture: Aquaculture Pathophysiology and Aquaculture Phar- macology published by Elsevier Inc., Academic Press. Dr. Roger Sie-Maen Chong is a veterinary specialist in Australia and the United Kingdom, with expertise in fish and shellfish pathology as applied to the health and biosecurity of aquacultured species. He is officially regis- tered as a specialist by the Queensland Board of Veterinary Surgeons for Veterinary Aquatic Animal Health (Australia) and by the Royal College of Veterinary Surgeons for Fish Health and Production (United Kingdom). He is also a certified fish pathologist recognized by the Fish Health Section of the American Fisheries Society. He has worked in Hong Kong with the Department of Agriculture, Fisheries & Conservation, in Queensland with the Biosecurity Queensland and is presently a research fish pathologist with the Australian Commonwealth Scientific and Industrial Research Organization (CSIRO). He is editor of the accompanying two textbooks on the theme of aquaculture: Aquaculture Pathophysiology and Aquaculture Pharmacology published by Elsevier Inc., Academic Press. xi
  • 14. Preface The textbook Aquaculture Toxicology focuses on the practical principles of toxicology of finfish (mainly), crustaceans, and mollusks, the three major groups of aquatic animal species cultured for human consumption. Recent books on this subject have a more general approach on aquatic tox- icology, focusing more in chemical aspects of toxicology and pollutants (Introduction to Aquatic Toxicology by Nikinmaa, M., Elsevier, 2014; Microscale Testing in Aquatic Toxicology by Wells et al., CRC Press, 2018) or the specific aspects of the effects of pollutants (Aquatic Toxicology: Molecular, Biochemical, and Cellular Perspectives by Malins D.C. and Ostrander, G.K., 2018). Aquaculture is a rapidly growing agricultural sector and requires updated research information on general aspects of several types of toxicants to control or avoid their negative impacts on the culture of aquatic animals. The book is multiauthored and edited. All contributing authors for the different chapters are highly respected international experts recognized in their specific areas, who have published several articles dealing with the sub- ject of their respective chapters; some have also written book chapters on the subject. Each book chapter has been written from the perspective of the expert, providing the reader with nuances of the topic without compromis- ing on the essential and useful facts or being encyclopedic but reflecting global research. Aquaculture Toxicology presents an overview of the practical information on the effects and sources of most common pollutants: disinfec- tants and antifoulants, metals, agrochemicals, pharmaceuticals, oils and derivatives, and microplastics. The authors were encouraged to use the same format in all chapters to facilitate ease of reading and studying, and to maintain consistency throughout the book although the ultimate approach chosen by different authors is reflective of the state of knowledge on the respective topics. A list of subtitles is included at the beginning of each chapter to provide the reader with a quick summary of what is covered in each chapter. This book provides the target audience with a reliable and valuable up- to-date, “all-inclusive” reference and guide to the state of the field, serving as a systematic and concise resource for aquaculture specialists/researchers interested in toxicity of various agents to fish, crustaceans, and mollusks, and particularly researchers, clinical veterinarians, and possibly government xiii
  • 15. personnel interested in aquaculture, the fisheries and comparative biology, and how treatments may affect the aquatic animals directly. It is hoped that having such a comprehensive easily readable book focused on aquaculture will identify areas where more research is needed to generate more knowl- edge to support a sustainable aquaculture industry. The editors acknowledge the authors for their contributions. Frederick S.B. Kibenge Bernardo Baldisserotto Roger Sie-Maen Chong EDITORS xiv Preface
  • 16. CHAPTER ONE Introduction to aquaculture Frederick S.B. Kibenge Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada 1.1 Introduction The Food and Agricultural Organization of the United Nations (FAO) attributes aquatic organisms that are harvested by an individual or corporate body which has owned them throughout their rearing period to aquaculture. In contrast, aquatic organisms that are exploitable by the public as a common property resource, with or without appropriate licenses, are the harvest of fisheries (FAO, 2015). Two critical criteria of human activ- ity, ownership of stock and deliberate intervention in the production cycle, distinguish aquaculture from capture fisheries and also account for the envi- ronmental concern centered on water quality/water pollution that consti- tutes Aquaculture Toxicology. It has been noted that the environmental impacts of aquaculture vary with species, system, management, production intensity, location, and environmental carrying capacity to absorb impacts (FAO, 2016). For example, the intensive rearing of fish has led to an increase in water pollution per unit of farmed fish produced (Hall et al., 2011). On the contrary, the filter feeding finfish typically raised in inland multispecies aquaculture systems (mostly silver carp Hypophthalmichthys molitrix and big- head carp H. nobilis, and most recently Mississippi paddlefish Polyodon spathula) and marine bivalve mollusks (oysters, mussels, clams, and scallops) raised in seas, lagoons, and coastal ponds require no artificial feeding (FAO, 2018) and improve the water quality in the production system by removing waste materials, including waste from fed aquatic animal species, and low- ering the nutrient load (FAO, 2018; Hishamunda et al., 2014; Parisi et al., 2012). Deep-sea aquaculture is associated with a lower environmental impact on the seafloor (Welch et al., 2019) because of deeper waters and stronger ocean currents that disperse organic matter from farms, in contrast to nearshore farming. This introductory chapter describes the structure of the global aquacul- ture industry (finfish, mollusks, crustaceans, in cold water and warm water, Aquaculture Toxicology © 2021 Elsevier Inc. https://doi.org/10.1016/B978-0-12-821337-7.00007-4 All rights reserved. 1
  • 17. commercial and noncommercial, and small and big operations) and its importance in supplying animal protein food to the growing human popu- lation. A better understanding of the aquaculture methods will allow the reader to recognize the full implications of the toxic effects associated with different aquaculture environments and help improve toxicological risk management for aquaculture. The chapters that follow provide an overview of practical information covering five main aspects of Aquaculture Toxicology in the three main aquaculture groups (fish, crustaceans, and mollusks): (1) water quality criteria/guidelines used internationally and models used to predict the toxicity of contaminants; (2) the primary disinfectants and organic antifouling co-biocides currently used in aquaculture, pharmaceu- ticals used in human and veterinary medicine and their by-products that enter the aquatic environment; (3) water pollutants such as metals, oils and their derivatives, and microplastics that are toxic to aquatic animals but arising from nonaquaculture sources; (4) mechanisms of toxicity and the responses to toxic agents including aspects of uptake, metabolism, and excretion of toxicants in fish, crustaceans, and mollusks, and toxic effects on nontarget aquatic organisms; and (5) brief overviews of the current regulatory aspects of the use of these products. 1.2 Structure of the global aquaculture industry The contribution of wild-catch fisheries as an animal protein source for human consumption plateaued in the mid-1980s, and since then, most natural stocks in marine waters have been harvested at, or near-maximum rates, with the quantity of fish produced by capture fisheries, projected to increase at only 0.2% per year for the period 2019–2028 (OECD/FAO, 2019). In contrast, the average growth in the aquaculture sector in the same period is projected at 2.0% per year (OECD/FAO, 2019). Since 2015, aquaculture has overtaken capture fisheries as the source of seafood for human consumption, as global fisheries have remained flat and will continue to be flat for the foreseeable future (OECD/FAO, 2019). This share of aquaculture is projected to rise to 62% by 2030 as catches from wild capture fisheries level off (FAO, 2014; World Bank, 2013). Fish, mollusks, and crustaceans represent the most economically important global aquaculture industry subsectors (Fig. 1.1), at 80.04 million tonnes in 2016 with an estimated total farm gate value of USD 154.2 billion (FAO, 2018), and expected to reach USD 202.96 billion by 2020 (Grand View Research Inc., 2014). 2 Frederick S.B. Kibenge
  • 18. Most of the global aquaculture production (89% by volume) is located in countries in Asia (most notable being China, Indonesia, India, Vietnam, South Korea, and the Philippines; production involves mostly freshwater species, i.e., inland aquaculture). In terms of marine aquaculture, Norway’s Atlantic salmon industry makes it the world’s largest marine aquaculture producer, although this accounts for just 3% of total world farmed finfish output (Cooke, 2016). Another top aquaculture producer is Egypt, whose tilapia and shrimp farming have exponentially increased in the last two decades, and by 2017 at approximately 1.3 million metric tons, surpassed total production by Norway (1.19 million metric tons) and Chile (1.11 million metric tons) (Tran, 2019). 1.2.1 Aquatic animal species in aquaculture Among the three main aquaculture groups (fish, crustaceans, and mollusks), there were 369 finfishes (including five hybrids), 109 mollusks, and 64 crus- taceans species recorded by FAO as cultured in 2016 (FAO, 2018). Carp dominates production in both China and the rest of Asia; for Europe and South America, it is salmonids; African aquaculture production is almost exclusively tilapias; for Oceania, shrimps and prawns dominate (Hall et al., 2011). In the USA, catfish predominate (Cooke, 2016). The most important farmed species (with a production of 1% or more of the total in 2016) (FAO, 2018) are listed in Table 1.1. However, the analysis of aqua- culture production and details about farmed species remain approximations because many indigenous aquatic species are used in aquaculture without (A) (B) 21% 10% 68% 1% Mollusks Crustaceans Fish Other species 11% 24% 62% 3% Mollusks Crustaceans Fish Other species Fig. 1.1 World aquaculture by farmed species sector. (A) Aquaculture industry subsec- tors by quantity 2016 and (B) aquaculture industry subsectors by value 2016. Adapted from FAO, 2018. Leading species in global aquaculture production in 2016 (in million metric tons). Statista. Statista Inc. https://www.statista.com/statistics/240268/top-global- aquaculture-producing-countries-2010/ Accessed: July 14, 2019. 3 Introduction to aquaculture
  • 19. Table 1.1 Major farmed species in world aquaculture. Aquaculture sector Species or species groupsa % of total, 2016 Finfish Grass carp (Ctenopharyngodon idellus) (FW) 11 Silver carp (Hypophthalmichthys molitrix) (FW) 10 Tilapias (Oreochromis niloticus) other cichlids (FW) 10 Common carp (Cyprinus carpio) (FW) 8 Bighead carp (Hypophthalmichthys nobilis) (FW) 7 Crucian carp (Carassius carassius) (FW) 6 Major (Indian) carp (Catla catla) (FW) 6 Freshwater fishes nei, Osteichthyes (FW) 4 Atlantic salmon (Salmo salar) (D) 4 Roho labeo (Labeo rohita) (FW) 3 Pangas catfishes (Pangasius spp.) (FW) 3 Milkfish (Chanos chanos) (D) 2 Torpedo-shaped catfishes nei (Clarias spp.) 2 Marine fishes nei (Osteichthyes) (M) 2 Wuchang bream (Megalobrama amblycephala) (FW) 2 Rainbow trout (Oncorhynchus mykiss) (D) 1 Cyprinids (Cyprinidae) (FW) 1 Black carp or black Chinese roach (Mylopharyngodon piceus) (FW) 1 Northern snakehead (Channa argus) (FW) 1 Other finfishes 16 Finfish total 100 Crustaceans White leg shrimp (Litopenaeus vannamei, formerly Penaeus vannamei) 53 Red swamp crawfish (Procambarus clarkii) 12 Chinese mitten crab (Eriocheir sinensis) 10 Giant tiger prawn or Asian tiger shrimp (Penaeus monodon) 9 Oriental river prawn (Macrobrachium nipponense) 4 Giant river prawn (Macrobrachium rosenbergii) 3 Other crustaceans 9 Crustaceans total 100 Mollusks Cupped oysters nei (Crassostrea spp.) 28 Japanese carpet shell or Manila clam (Ruditapes philippinarum) 25 Scallops (Pectinidae) 11 4 Frederick S.B. Kibenge
  • 20. being registered individually in national statistics. Numerous single species registered in the official statistics of many countries consist, in reality, of multiple species and sometimes hybrids (i.e., the number of finfish hybrids in commercial production is more than five) (FAO, 2018). In China, more than 200 species are farmed commercially, but the total production is registered under fewer than 90 species and species groups. Similarly, in India and Vietnam, the number of cultured species far exceeds the number included in statistics (FAO, 2014). Moreover, for the most widely farmed species, tilapia, the correct number of producer coun- tries is higher than the FAO record of 135 countries because commercially farmed tilapias are not yet reflected separately in national statistics in Canada and some European countries (FAO, 2014). In terms of the projected increase in aquaculture production, by 2028, carp and mollusks are projected to remain the most significant aquaculture groups, accounting for 35.8% and 19.2%, respectively, of total production (OECD/FAO, 2019). 1.2.2 Aquaculture techniques, systems, and facilities The techniques, systems, and facilities used in aquaculture are as diverse as the species currently being raised and also vary by geographical region (Bostock et al., 2010), but typically encompass three stages: incubation/ hatchery seed production, early-rearing, and on-growing (Roberts and Shepherd, 1974). In salmon and trout aquaculture, on-growing has merged with husbandry and breeding (Aarset and Borgen, 2015). For new farmed Table 1.1 Major farmed species in world aquaculture—cont’d Aquaculture sector Species or species groups % of total, 2016 Marine mollusks (Mollusca) 7 Sea mussels (Mytilidae) 6 Chinese razor clam or Agemaki clam or constricted tagelus (Sinonovacula constricta) 5 Pacific oyster, Japanese oyster, or Miyagi oyster (Crassostrea gigas) 3 Blood cockle or Blood clam (Anadara granosa) 3 Chilean mussel (Mytilus chilensis) 2 Other mollusks 10 Mollusks total 100 a Major farmed species or species groups (with a production of 1% or more of the total in 2016) (FAO, 2018). FW, freshwater; D, diadromous (these fish spawn in freshwater and migrate to the sea for the main growing period); M, marine. 5 Introduction to aquaculture
  • 21. species like cod, mainly two methods are used: one is based on capturing wild cod for on-growing, the other focuses on the production of cod from hatchery seed to market size; currently, on-growing of wild cod (e.g., as in sea ranching (Kitada, 2018)) is more economically efficient than using farmed juveniles (Gunnarsson, 2007). For a few species, such as eels “Anguilla spp.,” farming still relies entirely on the wild seed. Although the Japanese eel “Anguilla japonica” life cycle in captivity has been completed, the techniques for mass production of glass eels have not yet been established because of various technical difficulties (Bird, 2013; Masuda et al., 2012). A comprehensive review of the different aquaculture systems worldwide can be found in Boyd and McNiven (2015). World aquaculture production takes place under four main systems: (1) on land (using freshwater or saline water) in static water ponds (e.g., for growing channel catfish and other warm-water species), concrete raceway systems (e.g., for growing rainbow trout), fresh water gravity tanks, or large recirculation tanks; (2) in floating cages and net pens in a lake or river (e.g., for growing salmonids and other cold-water species that require clean water with high oxygen levels) or on the shoreline/nearshore in sheltered waters (mariculture or marine aquacul- ture 3km from the shore) in floating net cages moored to the bottom in the sea with long lines (Shepherd, 1993; White and Edwards, 2015); (3) in coastal lagoons or brackish-water or marine ponds (e.g., for shellfish aquaculture) (Parisi et al., 2012; Wever et al., 2015; White and Edwards, 2015); and (4) in onshore-based tanks using pumped sea water (e.g., for flat fish farming of turbot or halibut that normally lie on the bottom and will not shoal within the water column inside a floating cage (Shepherd, 1993)). 1.2.3 Finfish aquaculture Seven of the top ten cultured fish species are carps; others are tilapias, Pangas catfishes, and Atlantic salmon (Table 1.1). China, the largest producer of farmed seafood, grows carp mostly in ponds and rice paddies, with little or no attempt to actively nurture the animals and has been practicing this type of aquaculture for thousands of years. Most carp farming is pond-based, with several species stocked in the same pond (polyculture) (SPC, 2011). Tilapia and sometimes catfish are stocked together with carp. Single-species culture (monoculture) is rare, except in the flow-through system and cage culture of common carp in streams or canals. There are different stocking models for polyculture, depending on the availability of the primary source of feed. If grasses (aquatic or terrestrial) are abundant, grass carp can be 6 Frederick S.B. Kibenge
  • 22. stocked as the dominant species. The leftover feed and grass carp excreta would sufficiently fertilize the pond water for the growth of filter feeders. For example, the “80:20 pond fish culture” where 80% of harvest weight comes from the pellet-fed target species (such as grass carp, crucian carp, or tilapia) and the other 20% comes from the filter feeding “service species” (silver carp) (White and Edwards, 2015). Pond-based carp culture has been traditionally integrated with crop farming (rice, mulberry, fruit, and vege- tables) and animal husbandry (ducks, swine, and chicken) in China (White and Edwards, 2015). The practice has been widely introduced to many other parts of the world, with some modifications to fit into local conditions (SPC, 2011). Polyculture (the mixing of species in fish farms) has taken a different trajectory since 2008 and is widely used in sea cages for a different purpose in the form of using “cleaner fish” (lumpfish Cyclopterus lumpus and wrasse (Labridae)) in marine farmed salmonids as a biological control method for sea lice Lepeophtheirus salmonis in Europe (Powell et al., 2018; Skiftesvik et al., 2014) and Canada; it involves the use of wild-caught cleaner fish directly in the salmon farms or as broodstock for hatchery-raised cleaner fish (EURLFD, 2016). In industrial aquaculture, farmed fish are reared at high population densities in floating open net cages nearshore (for marine aquaculture) or in a lake or river (for inland aquaculture) (White and Edwards, 2015). The cages are either of square/hexagonal steel platform construction that are linked together or are of circular polyethylene rings 10–50m deep with netting to hold in farmed fish. Expansion can simply be by increasing the number of fish in a cage (i.e., cage volume) or by increasing the number of cages. Formulated dry feeds supply all nutrition. Uneaten feed and feces fall through the cages and settle to the bottom in the vicinity. Cages are periodically moved to new locations to allow benthic communities affected by sediment to recover—a process called fallowing (Boyd and McNiven, 2015). Current production systems operate on a single-year-class stocking in a site, usually a bay (“All-in, all-out”) with a fallow period of 6 months in between year classes. Closed containment is a practice that entails enclosing fish in floating containers or land-based farms to lessen their damage to the aquatic environ- ment (Real, 2010). Recent improvements in offshore technology now allow even larger floating fish cages out in the sea that are submersible with automated feeding systems and remote monitoring. This has enabled the expansion of aquaculture farther offshore (i.e., deep-sea aquaculture) into high-energy sites and with a low environmental impact on the seafloor 7 Introduction to aquaculture
  • 23. (Lovatelli et al., 2013; Welch et al., 2019). China currently has one of the world’s biggest fully submerged net cage farming Atlantic salmon in the Yel- low Sea (Owen, 2018); and SalMar’s Ocean Farm 1 is 40km off the coast of Frohavet, Norway (Bennet, 2019). Moving fish farms out to sea helps to solve several problems. The open ocean offers more space, deeper waters, and stronger currents. Ocean currents are particularly effective for reducing the spread of pathogens and allowing better exchange and dilution of wastes than nearshore farming; greater distance offshore also minimizes interactions with wild fish and reduces the risk of unwanted exposure of nontarget organisms to aquacultural chemicals (Park et al., 2012). On land, increased development of land-based recirculating aquaculture system (RAS) (Espinal and Matuli c, 2019) is leading to an ever-increasing move to saltwater land-based aquaculture, particularly in Europe and most recently in North America, despite the significant capital costs compared to those for floating cage farms. RAS offers environmentally sustainable methods for farming marine (Tal et al., 2009) and freshwater fish by having minimal effluents compared to other systems (White and Edwards, 2015). For example, in BC-Canada, a recent analysis for the Fraser Basin Council found that a capital investment of $1.1 billion would be required to establish a land-based industry capable of producing 50,000 tons of Atlantic salmon a year on Vancouver Island (Shore, 2019). There is already extensive knowl- edge derived from land-based hatcheries. The capital costs are compensated by lower operating costs, for example, land-based aquaculture farms have low pharmaceutical costs (e.g., no sea lice therapeutics) and no costs of maintaining boats that go out to feed the fish (Kramer, 2015). Moreover, with land-based farming, there would be no interactions between farmed fish and wild fish (Shore, 2019). However, while land- based aquaculture requires low antibiotic usage, there appears to be a con- nection in antimicrobial resistance issues found in land-based aquaculture with those established by terrestrial animal agriculture (Done et al., 2015). Another crucial disadvantage has been the development of “off-flavor” of the harvested fish “caused by geosmin and 2-methylisoborneol metabolites released by microbes that grow within the land-based systems” (Sapin et al., 2020). Another aquaculture development that has gained traction in recent years is the biofloc technology (White and Edwards, 2015). Biofloc technol- ogy is a technique of enhancing water quality in aquaculture through the manipulation of microbiota to convert the harmful waste from aquaculture production to consumable body biomass, with many other benefits (Dauda, 8 Frederick S.B. Kibenge
  • 24. 2019). The technology has recently gained attention as a sustainable method to maintaining optimum water quality parameters under a zero-water exchange system, thus preventing eutrophication and effluent discharge into the surrounding environment, thereby increasing biosecurity, as there is no water exchange except sludge removal (Ahmad et al., 2017). The technol- ogy has the added value of producing proteinaceous feed in situ, which results in higher productivity with less impact on the environment (Bossier and Ekasari, 2017). It has been considered the new “blue revolu- tion” in aquaculture (Emerenciano et al., 2017). It may act as a complete source of nutrition for aquatic organisms, along with some bioactive compounds that will enhance growth, survival, and defense mechanisms and acts as a novel approach for health management in aquaculture by stimulating the innate immune system of animals. Beneficial microbial bac- terial floc and its derivative compounds such as organic acids, polyhydroxy acetate, and polyhydroxy butyrate could resist the growth of other pathogens and thus serve as a natural probiotic and immunostimulant. This technology is economically viable, environmentally sustainable, and socially acceptable (Ahmad et al., 2017; Daniel and Nageswari, 2017). 1.3 Mollusk aquaculture In the case of mollusk (oysters, clams, scallops, abalone, mussels, cockles, and related species) aquaculture, there are many varieties of culture and grow-out methods that are particular to species and locations (Boyd et al., 2005; Dı́az et al., 2011; Dumbauld et al., 2009; Elston, 1999; Elston and Ford, 2011; Parisi et al., 2012). For example, Parisi et al. (2012), in discussing the diversification of Italian shellfish culture, reviewed the most promising mollusk species and their culture in general (refer to Table 1.1 for a list of the most notable farmed mollusk species worldwide). Most mollusk culture requires no feed inputs (algae are used to feed the larvae and juveniles in hatcheries to provide spat for mollusk culturing) but may require control of fouling and predators. Seed bivalves are produced either in land-based hatcheries (Robert, 2009) or from natural populations (wild spat) (Parisi et al., 2012). They can be transported over considerable distances to grow-out sites in estuaries and even to different countries (FAO, 2013). Farming mollusks is limited in several countries because of limited capacity producing seed from mollusk hatcheries and nurseries (FAO, 2014), relying on the wild seed. The use of wild seed is impossible if the natural populations of mollusks are not suited to culture. 9 Introduction to aquaculture
  • 25. Intensification will require a reliable, plentiful, and inexpensive supply of hatchery seed, requiring the selection and management of broodstocks and the controlled production of high-quality seed stocks (Elston and Ford, 2011). This would reduce the environmental biosecurity concern of the translocation of non-native species (Parisi et al., 2012). 1.4 Crustacean aquaculture The most recent dramatic change in aquaculture has been the explo- sive growth in shrimp farming in Southeast Asia (Cressey, 2009). The production has increased almost exponentially since the mid-1970s (FAO, 2010). This rapid increase largely reflects the dramatic increase in white leg shrimp Litopenaeus vannamei (formerly Penaeus vannamei) culture in Asia (China, Thailand and Indonesia) and Latin America (Ecuador and Mexico) (Bondad-Reantaso et al., 2012), where the penaeid shrimps have tended to dominate due to high-value, short-production cycles and accessible technologies (Bostock et al., 2010). Crustacean farming, similarly to marine fish aquaculture, requires a high-quality diet, usually containing fish meal and often fish oil (Bostock et al., 2010). 1.5 Chemicals in aquaculture There is a long list of chemicals that are used in aquaculture, including agricultural limestone, lime, fertilizers, oxidants, coagulants, osmoregulators, algicides, herbicides, fish toxicants, antifoulants, therapeu- tics, disinfectants, anesthetics, agricultural pesticides, and hormones (Arthur et al., 2000; Boyd and Massaut, 1999; Boyd and Tucker, 1998; Noga, 2010; Schnick, 2001). To mitigate the environmental impact associated with the use of aquacultural chemicals, various regulations have been advocated (FAO, 1997). In many countries, governmental regulations on chemical use in aquaculture have been established (Cabello, 2006; Schnick, 1988, 2001) (refer also to Martins and Martins (2020) in Chapter 3 (Section 3.4), Loro (2020) in Chapter 5 (Section 5.4), and de Assis (2020) in Chapter 6 in this book. Most importing countries also have food safety regulations that involve the inspection of incoming shipments of seafood products for specific chemical residues. A companion textbook, Aquaculture Pharmacology (Kibenge et al., 2020), has a comprehensive review of most aquaculture pharmaceuticals. The pharmaceuticals used in human and veterinary medicine (including aquaculture) and their by-products enter the aquatic 10 Frederick S.B. Kibenge
  • 26. environment as pollutants in a variety of ways, causing adverse effects on nontarget aquatic organisms. The aquatic environment may also be contam- inated by chemicals such as agrochemicals, metals, oils and their derivatives, and microplastics as a result of erosion of surface deposits of metal minerals, as well as from human activities, such as agriculture, mining, smelting, fossil fuel combustion, and industrial and commercial uses of metals (Nordberg et al., 2007; Pandey et al., 2019). Martinez et al. discuss metal pollutants that are toxic to aquatic animals in Chapter 4, Loro discusses agrochemical pollutants in Chapter 5, de Assis discusses pharmaceutical pollutants in Chapter 6, Sadauskas-Henrique et al. discuss oil and derivatives pollutants in Chapter 7, and de Araújo et al. discuss microplastics and associated pollutants in Chapter 8 in this book. Additional information on chemicals in aquaculture and the contribution of aquaculture to chemical pollution and other adverse impacts of chemical use by humans can be found in Boyd and McNiven (2015). 1.6 Governance of aquaculture The FAO (2017) technical guidelines on “aquaculture governance and sector development” define aquaculture governance as “the set of processes by which a jurisdiction manages its resources concerning aquacul- ture, how its stakeholders participate in making and implementing decisions affecting the sector, how government personnel are accountable to the aquaculture community and other stakeholders, and how the respectful rule of law is applied and enforced.” Most countries have some form of legisla- tion governing aquaculture operations (with regard to animal welfare, animal diseases, the environment, water use, land use, and waste disposal), with the competent authorities residing in various government ministries and agencies. Given the diversity of countries and aquaculture systems, it is beyond the scope of this chapter to consider legislation in each country. Instead, the reader is referred to a series of comparative national overviews of aquaculture laws and regulations, “National Aquaculture Legislation Overview (NALO),” from aquaculture producing countries that are published by the FAO as NALO Fact sheets (FAO, 2019). These fact sheets are updated every 2 to 3 years (FAO, 2019). At the national level, aquacul- ture operations require various licenses and permits to operate, ensuring environmental protection relating to the waste generated, prevention, and control of aquatic animal diseases, and the well-being of aquaculture animals (FAO, 2019). There are also Policy Frameworks mandated 11 Introduction to aquaculture
  • 27. nationally, regionally, or internationally on how aquaculture activities are developed and managed. These guidelines and codes of conduct provide good practices for a variety of aquaculture operations and how the activities are regulated in both freshwater and marine environments as well as for land-based aquaculture. The ultimate purpose of governance of the aqua- culture sector should be to support sustainable aquaculture by emphasizing environmental sustainability and social responsibility. Enhancement of aquaculture’s growth needs the right policy decisions regarding the use of natural resources (water, land, seed, and feed), as well as sound environmen- tal management. Good governance is fundamental to the successful formulation and implementation of aquaculture development policies, strategies, and plans (FAO, 2016; Hishamunda et al., 2014). Three main environmental actions arising from good governance are: (1) management of effluent and nutrient loading, (2) improvement of aquaculture legislation, and (3) mandatory environmental impact assessment (EIA) (FAO, 2016; Hishamunda et al., 2014). References Aarset, B., Borgen, S.O., 2015. The battle of the eyed egg: critical junctures and the control of genes in Norwegian salmon farming. Aquaculture 445, 70–78. Ahmad, I., Rani, A.M.B., Verma, A.K., Maqsood, M., 2017. Biofloc technology: an emerg- ing avenue in aquatic animal healthcare and nutrition. Aquac. Int. 25, 1215–1226. Arthur, J.R., Lavilla-Pitogo, C.R., Subasinghe, R.P. (Eds.), 2000. Use of Chemicals in Aquaculture in Asia. Proceedings of the Meeting on the Use of Chemicals in Aquacul- ture in Asia. Southeast Asian Fisheries Development Center, Iloilo, Philippines. Bennet, N. 2019. Aquaculture industry is headed for a sea change. Available at https://www. coastreporter.net/news/local-news/aquaculture-industry-is-headed-for-a-sea-change- 1.23947488 (Accessed September 16, 2019). Bird, W., 2013. In Japan, Captive Breeding May Help Save the Wild Eel. Environment 360. Accessible at http://e360.yale.edu/feature/in_japan_captive_breeding_may_help_ save_the_wild_eel/2700/ (Accessed September 16, 2019). Bondad-Reantaso, M.G., Subasinghe, R.P., Josupeit, H., Cai, J., Zhou, X., 2012. The role of crustacean fisheries and aquaculture in global food security: past, present and future. J. Invertebr. Pathol. 110, 158–165. Bossier, P., Ekasari, J., 2017. Biofloc technology in aquaculture to support sustainable devel- opment goals. Microb. Biotechnol. 10, 1012–1016. Bostock, J., McAndrew, B., Richards, R., Jauncey, K., Telfer, T., Lorenzen, K., et al., 2010. Aquaculture: global status and trends. Philos. Trans. R. Soc. B 365, 2897–2912. Boyd, C.E., Massaut, L., 1999. Risks associated with use of chemicals in pond aquaculture. Aquac. Eng. 20, 113–132. Boyd, C., McNiven, A., 2015. Aquaculture, Resource Use, and the Environment. Wiley Blackwell, p. 349. Boyd, C.E., Tucker, C.S. 1998. Pond Aquaculture Water Quality Management. Boston: Kluwer Academic Publishers. 624 pp. Boyd, C.E., McNevin, A.A., Clay, J., Johnson, H.M., 2005. Certification issues for some common aquaculture species. Rev. Fish. Sci. 13, 231–279. 12 Frederick S.B. Kibenge
  • 28. Cabello, F.C., 2006. Heavy use of prophylactic antibiotics in aquaculture: a growing problem for human and animal health and for the environment. Environ. Microbiol. 8, 1137– 1144. Cooke, M. 2016. BBFAW Investor Briefing – Animal Welfare in Farmed Fish. Available from https://www.bbfaw.com/media/1432/investor-briefing-no-23-animal-welfare- in-farmed-fish.pdf (Accessed October 03, 2019). Cressey, D., 2009. Future fish. Nature 458, 398–400. Daniel, N., Nageswari, P., 2017. Exogenous probiotics on biofloc based aquaculture: a review. Curr. Agric. Res. J. 5, 88–107. Dauda, A.B., 2019. Biofloc technology: a review on the microbial interactions, operational parameters and implications to disease and health management of cultured aquatic ani- mals. Rev. Aquacult., 1–18. https://doi.org/10.1111/raq.12379. de Assis, H.C.S. 2020. Chapter 6 Pharmaceutical pollutants. In Aquaculture Toxicology. Edited by Kibenge, F.S.B., Baldisserotto, B., Chong, R.S.M. Elsevier Inc, Academic Press. (in preparation). Dı́az, G.A., Seijo, L.C., Gaspar, M.B., da Costa González, F. 2011. Razor Clams: Biology, Aquaculture and Fisheries. Consellerı́a do Mar, Xunta de Galicia ed., Santiago de Comp- ostela, Spain. Available from: ftp://ftp.cimacoron.org/razor_clams_2011.pdf (Accessed September 16, 2019). Done, H.Y., Venkatesan, A.K., Halden, R.U., 2015. Does the recent growth of aquaculture create antibiotic resistance threats different from those associated with land animal pro- duction in agriculture? Am. Assoc. Pharm. Sci. J. 17, 513–524. https://doi.org/10.1208/ s12248-015-9722-z. Dumbauld, B.R., Ruesink, J.L., Rumrill, S.S., 2009. The ecological role of bivalve shellfish aquaculture in the estuarine environment: a review with application to oyster and clam culture in west coast (USA) estuaries. Aquaculture 290, 196–223. Elston, R.A. 1999. Health Management, Development and Histology of Seed Oysters. World Aquaculture Society, Baton Rouge, LA, USA. 110 pp. Elston, R.A., Ford, S.E., 2011. Chapter 13 Shellfish diseases and health management. In: Shumway, S.E. (Ed.), Shellfish Aquaculture and the Environment, first ed. John Wiley Sons Inc, pp. 359–394. Emerenciano, M.G.C., Martı́nez-Córdova, L.F., Martı́nez-Porchas, M., Miranda-Baeza, A., 2017. Chapter 5 Biofloc Technology (BFT): A Tool for Water Quality Management in Aquaculture. Intech, https://doi.org/10.5772/66416. Espinal, C.A., Matuli c, D., 2019. Chapter 3 Recirculating aquaculture technologies. In: Goddek, S., Joyce, A., Kotzen, B., Burnell, G.M. (Eds.), Aquaponics Food Production Systems. Springer Nature, Switzerland AG, pp. 35–76, https://doi.org/10.1007/978-3- 030-15943-6_3. EURLFD (European Union Reference Laboratory for Fish Diseases). 2016. Scientific meet- ing report on cleaner fish in aquaculture 2016. https://www.eurl-fish-crustacean.eu/ fish/scientific-reports (Accessed August 01, 2018). FAO, 2010. The State of World Fisheries and Aquaculture 2010. Rome, FAO. 2010. 197 pp. FAO, 2013. Hatchery Culture of Bivalves: A Practical Manual. FAO Fisheries Technical Paper 471. Accessible online ftp://ftp.fao.org/docrep/fao/007/y5720e/y5720e00.pdf. FAO, 2014. The State of World Fisheries and Aquaculture 2014. FAO, Rome. 223 pp. FAO, 2015. Fishery statistical collections: global aquaculture production. Accessible online http://www.fao.org/fishery/statistics/global-aquaculture-production/en Accessed: July 14, 2019. FAO, 2016. The State of World Fisheries and Aquaculture 2016. Contributing to Food Security and Nutrition for all. FAO, Rome. 200 pp. FAO, 2017. Aquaculture Development. 7. Aquaculture governance and sector development. FAO Technical Guidelines for Responsible Fisheries. No. 5. Suppl. 7. Rome, Italy. 50 pp. 13 Introduction to aquaculture
  • 29. FAO, 2018.Leading Species in Global Aquaculture Production in 2016 (in million metric tons). Statista. Statista Inc. https://www.statista.com/statistics/240268/top-global- aquaculture-producing-countries-2010/ Accessed: July 14, 2019. FAO, 2019. National Aquaculture Legislation Overview (NALO) Fact Sheets for different countries. Available at http://www.fao.org/fishery/collection/nalo/en (web archive link, 01 September 2019) and http://www.fao.org/fishery/nalo/search/en (Accessed September 1, 2019). FAO (Food and Agriculture Organization of the United Nations), 1997. Aquaculture Devel- opment. FAO Technical Guidelines for Responsible Fisheries 5. FAO, Rome. Grand View Research, Inc., 2014. Aquaculture Market Analysis By Culture Environment (Fresh Water, Marine Water, Brackish Water), By Product (Carps, Crustaceans, Mack- erel, Milkfish, Mollusks, Salmon, Sea Bass, Sea Bream, Trout) and Segment Forecasts To 2020. Available at: http://www.grandviewresearch.com/industry-analysis/aquaculture- market and at: http://www.thefishsite.com/fishnews/23604/world-aquaculture- market-to-reach-20296-billion-by-2020#sthash.STzI17Ql.dpuf (Accessed: April 02, 2016). Gunnarsson, V.I., 2007. http://www.fisheries.is/aquaculture/species/cod/. (Accessed 2 April 2016). Hall, S.J., Delaporte, A., Phillips, M.J., Beveridge, M., O’Keefe, M., 2011. Blue Frontiers: Managing the Environmental Costs of Aquaculture. The WorldFish Center, Penang, Malaysia. http://www.conservation.org/publications/documents/BlueFrontiers_ aquaculture_report.pdf. (Accessed 2 April 2016). Hishamunda, N., Ridler, N., Martone, E. 2014. Policy and Governance in Aquaculture: Les- sons Learned and Way Forward. FAO Fisheries and Aquaculture Technical Paper No. 577. Rome, FAO. 48pp. Kibenge, F.S.B., Baldisserotto, B., Chong, R.S.M. (Eds.), 2020. Aquaculture Pharmacology. Elsevier Inc, Academic Press. in preparation. Kitada, S., 2018. Economic, ecological and genetic impacts of marine stock enhancement and sea ranching: a systematic review. Fish Fish. 19, 511–532. Kramer, L. 2015. Land-based salmon aquaculture: a future with potential. Available at https://www.seafoodsource.com/news/aquaculture/land-based-salmon-aquaculture- a-future-with-potential (Accessed September 16, 2019). Loro, V.L., 2020. Chapter 5 Agrochemicals: Contamination of environment, effects on wild- life, strategies for mitigating impacts and new perspectives to legislation. In: Kibenge, F.S. B., Baldisserotto, B., Chong, R.S.M. (Eds.), Aquaculture Toxicology. Elsevier Inc, Aca- demic Press. in preparation. Lovatelli, A., Aguilar-Manjarrez, J., Soto, D. (Eds.) 2013. Expanding mariculture farther off- shore—Technical, environmental, spatial and governance challenges. FAO Technical Workshop. 22–25 March. 2010. Orbetello, Italy. FAO Fisheries and Aquaculture Pro- ceedings No. 24. Rome, FAO. 73 pp. Includes a CD–ROM containing the full docu- ment (314 pp). (also available at http://www.fao.org/docrep/018/i3092e/i3092e00. htm). Martins, S.E., Martins, C.M.G., 2020. Chapter 3 Antifoulants and disinfectants. In: Kibenge, F.S.B., Baldisserotto, B., Chong, R.S.M. (Eds.), Aquaculture Toxicology. Elsevier Inc, Academic Press. in preparation. Masuda, Y., Imaizumi, H., Oda, K., Hashimoto, H., Usuki, H., Teruya, K., 2012. Artificial completion of the Japanese Eel, Anguilla japonica, life cycle: challenge to mass production. Bull. Fisheries Res. Agency 35, 111-117. Accessible online https://www.fra.affrc.go.jp/ bulletin/bull/bull35/35-13.pdf. Noga E.J. 2010. Fish Disease, Diagnosis and Treatment, second ed. Iowa State Press, Ames, Iowa. 536 pp. 14 Frederick S.B. Kibenge
  • 30. Nordberg, G.F., Fowler. B.A., Nordberg, M., Friberg, L.T., 2007. Handbook on the Tox- icology of Metals, third ed. Elsevier, Amsterdam. 1024 pp. OECD/FAO, 2019. OECD-FAO Agricultural Outlook 2019-2028. OECD Publishing, Paris/Food and Agriculture Organization of the United Nations, Rome, https://doi. org/10.1787/agr_outlook-2019-en. Owen, E., 2018. China gets ready to harvest first batch of farmed salmon from huge, deep sea fully-submersible fish cage. Available at https://salmonbusiness.com/chinas-gets-ready- to-harvest-first-batch-of-farmed-salmon-from-huge-deep-sea-fully-submersible-fish- cage/ (Accessed November 21, 2018). Pandey, L.K., Park, J., Son, D.H., Kim, W., Islam, M.S., Choi, S., Lee, H., Han, T., 2019. Assessment of metal contamination in water and sediments from major rivers in South Korea from 2008 to 2015. Sci. Total Environ. 651, 323–333. Parisi, G., Centoducati, G., Gasco, L., Gatta, P.P., Moretti, V.M., Piccolo, G., Roncarati, A., Terova, G., Pais, A., 2012. Molluscs and echinoderms aquaculture: biological aspects, current status, technical progress and future perspectives for the most promising species in Italy. Ital. J. Anim. Sci. 11, 4. https://doi.org/10.4081/ijas.2012.e72. Park, Y.H., Hwang, S.Y., Hong, M.K., Kwon, K.H., 2012. Use of antimicrobial agents in aquaculture. Revue Scientifique et Technique (International Office of Epizootics) 31, 189–197. Powell, A., Treasurer, J.W., Pooley, C.L., Keay, A.J., Lloyd, R., Imsland, A.K., de Leaniz, C.G., 2018. Use of lumpfish for sea-lice control in salmon farming: challenges and opportunities. Rev. Aquac. 10, 683–702. Real, N. 2010. DFO recognises potential of closed containment methods. Available at http://fis.com/fis/worldnews/worldnews.asp?l¼endb¼1id¼39422. Robert, R., 2009. Review on molluscs hatchery nursery development in Europe. pp 1–12. In: Proc. Symp. EAS, EUROSHELL Session, Trondheim, Norway. Roberts, R.J., Shepherd, C.J., 1974. Handbook of Trout and Salmon Diseases. Fishing News, Surrey, England, pp. 40–42. Sapin, R., Korban, D., Unlay, N., 2020. What are land-based salmon companies doing to tackle off flavors? Available at https://www.intrafish.com/aquaculture/we-asked- every-major-land-based-salmon-farmer-how-theyre-tackling-off-flavor-problems- heres-what-they-said-/2-1-752023?utm_campaign¼IFCO%3A%20Monthly% 20Land-Based%20Salmon%20-%20Mar%202020utm_source¼hs_emailutm_ medium¼emailutm_content¼85265239_hsenc¼p2ANqtz-_ 9KtqcaHfzksx8cItMBR6noN- IZC4x3a4Rwm7yjAelXkIOT7Kz288k2I8MmMU6zG-JbLN8bSlWeT4UQi4KtcC_ ALW1EA_hsmi¼85266785 (Accessed March 26, 2020). Schnick, R.A., 1988. The impetus to register new therapeutants for aquaculture. Progressive Fish-Culturist 50, 190–196. Schnick, R.A., 2001. Aquaculture chemicals. In: Kirk-Othmer Encyclopedia of Chemical Technology, fourth ed. vol. 3. John Wiley Sons, New York, pp. 209–225. Shepherd, J., 1993. Aquaculture systems. In: Brown, L. (Ed.), Aquaculture for Veterinarians: Fish Husbandry and Medicine. Pergamon Press Ltd., Oxford, pp. 43–55. Shore, R. 2019. U.S. firm seeks stake in B.C.’s only land-based Atlantic salmon farm. https:// vancouversun.com/news/local-news/u-s-firm-seeks-majority-stake-in-b-cs-only- land-based-salmon-farm. Skiftesvik, A.B., Blom, G., Agnalt, A.-L., Durif, C.M.F., Browman, H.I., Bjelland, R.M., Harkestad, L.S., Farestveit, E., Paulsen, O.I., Fauske, M., Havelin, H., Johnsen, K., Mortensen, S., 2014. Wrasse (Labridae) as cleaner fish in salmonid aquaculture—the Hardangerfjord as a case study. Mar. Biol. Res. 10, 289–300. https://doi.org/ 10.1080/17451000.2013.810760. 15 Introduction to aquaculture
  • 31. SPC, 2011. SPC Aquaculture Portal, Commodities Carp. Accessible here https://www.spc. int/aquaculture/images/commodities/pdf/Carp_page.pdf. Tal, Y., Schreier, H.J., Sowers, K.R., Stubblefield, J.D., Place, A.R., Zohar, Y., 2009. Envi- ronmentally sustainable land-based marine aquaculture. Aquaculture 286, 28–35. Tran, K., 2019. Egypt tops Norway, Chile in Aquaculture Production. https://www. intrafish.com/aquaculture/egypt-tops-norway-chile-in-aquaculture-production/2-1- 707157. (Accessed 22 April 2020). Welch, A.W., Knapp, A.N., El Tourky, S., Daugherty, Z., Hitchcock, G., Benetti, D., 2019. The nutrient footprint of a submerged-cage offshore aquaculture facility located in the tropical Caribbean. J. World Aquacult. Soc. 50, 299–316. https://onlinelibrary.wiley. com/doi/full/10.1111/jwas.12593. Wever, L., Krause, G., Buck, B.H., 2015. Lessons from stakeholder dialogues on marine aquaculture in offshore windfarms: perceived potentials, constraints and research gaps. Mar. Policy 51, 251–259. White, P., Edwards, P., 2015. Types of culture systems and aqua-ecosystems. Available at http://aquaculture.management/2015/types-of-culture-systems-and-aqua- ecosystems/ (Accessed March 26, 2020). World Bank, 2013. Fish to 2030: Prospects for Fisheries and Aquaculture (English). Agricul- ture and Environmental Services Discussion Paper; no. 3. World Bank Group, Washing- ton, DC. http://documents.worldbank.org/curated/en/458631468152376668/Fish- to-2030-prospects-for-fisheries-and-aquaculture. (Accessed 3 October 2019). 16 Frederick S.B. Kibenge
  • 32. CHAPTER TWO General introduction to toxicology of aquatic animals Bernardo Baldisserotto Department of Physiology and Pharmacology, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil 2.1 Introduction to toxicology Laboratory studies dealing with exposure to pollutants can last for hours to a few days (acute experiments) and are usually used to calculate the concentration that affects (effective concentration—EC50) or kills (lethal concentration—LC50) 50% of test organisms. Chronic studies are used to determine threshold concentrations (no observed effect concentration, or NOEC; lowest observed effect concentration, or LOEC). These values can be used to compare the effect of a given pollutant in different species or different pollutants between themselves. These values are used worldwide to derive water quality guidelines for the protection of aquatic life, i.e., concentrations that should result in a neg- ligible effect on aquatic biota. Two basic guideline derivation methodolo- gies are in use throughout the world to calculate these concentrations (Nugegoda and Kibria, 2013): one is the assessment factor method, which involves multiplying the lowest value of a set of toxicity data by a factor to arrive at a criterion value. For example, the LC50 value is multiplied by 0.01 and the NOEC value by 0.1. The assessment factor can vary according to the country and the amount of toxicological studies available. The other method is the species sensitivity distribution, a statistical extrap- olation involving the use of individual toxicity data for a range of species to determine the criterion value. This method estimates the concentration of a substance that is predicted to protect 95% of all aquatic species extrapolating from an equation or curve that considers the relationship between probabil- ity x log LC50 and NOEC. Some countries use either one of the methods, and others use a combination of both methods. Aquaculture Toxicology © 2021 Elsevier Inc. https://doi.org/10.1016/B978-0-12-821337-7.00004-9 All rights reserved. 17
  • 33. 2.2 Water quality criteria/guidelines The United States Environmental Protection Agency (USEPA) has water quality criteria/guidelines for water quality, and its website contains tables with the highest concentration of the most common metals, pesticides (mainly insecticides), and other pollutants or contaminants that are not expected to pose a significant risk to the majority of species in a given envi- ronment (USEPA, 2019). The same agency maintains the ECOTOX Knowledgebase Explore function (https://cfpub.epa.gov/ecotox/explore. cfm), which is an interactive way to examine search paths by chemical, spe- cies, and effects. The guidelines of the Canadian Council of Ministers of the Environment (CCME, 2003) explain that some water quality parameters can affect the toxicity of contaminants. Some are described later. – pH: At alkaline pH, many metals form insoluble hydroxides or carbon- ates that precipitate, while at acidic pH, a higher release of metals from the sediments can occur (CCME, 2003). Water pH may also influence toxicity in pharmaceuticals because the toxicity of sertraline and fluox- etine was higher and diclofenac was lower at pH8.2 than at pH5.8, but the toxicity of ethinyl estradiol was not affected by pH. Probably these differences are due to the higher uptake of sertraline at pH8.2 and no change in ethinyl estradiol uptake by pH (Alsop and Wilson, 2019). The piscicide 3-trifluoromethyl-4-nitrophenol (TFM), which is applied in the Great Lakes to control streams infested with larval sea lamprey (Petromyzon marinus), has 5.5-fold higher uptake rates at low pH (6.86) compared to alkaline pH (8.78). This higher uptake is most likely because the unionized, lipophilic form of TFM exists in greater amounts at a lower pH. On the contrary, the elimination rates are 1.7–1.8-fold higher at pH8.78 than at pH6.86, indicating that TFM is more effective at low pH (Hlina et al., 2017). – Hardness and alkalinity: The increase of water hardness usually reduces the toxicity of many metals, largely due to the formation of metal- carbonate complexes and Ca2+ and/or Mg2+ antagonism (Blewett and Leonard, 2017). CCME (2003) presents equations in which the values of water hardness are used to predict the concentrations of zinc and copper to protect aquatic life. The toxicity of the insecticides endosul- fan (Thiodan; 1,4,5,6,7-hexachloro-8,9,10-trinorborn-5-en-2,3-yelen) 18 Bernardo Baldisserotto
  • 34. (dimethyl) sulfite and methiocarb [Mesurol; 3,5-dimethyl-4-(methylthio) phenyl methylcarbamate] to rainbow trout, Oncorhynchus mykiss, is lower at higher alkalinity (40–121mg CaCO3/L) than at lower alkalinity (19–20mg CaCO3/L), but hardness ranging from 50 to 147mg CaCO3/L had no effect (Altinok et al., 2006; Capkin et al., 2006). Hardness (6–309mg CaCO3/L) also did not affect the toxicity of another insecticide, fenvalerate, to bluegill (Lepomis macrochirus) (Dyer et al., 1989). The increase of hardness increases surfactant toxicity to aquatic species in some cases, but the outcome is compound and species-specific (Lewis, 1992). – Salinity: The toxicity of metals in general decreases with the increase of salinity due to complexation with seawater ions (Blewett and Leonard, 2017; Tan et al., 2019). For example, nickel may complex with SO4 2 and Cl and free nickel reduces (Blewett and Leonard, 2017). The same complexation with Cl can be observed with cadmium (Tan et al., 2019). The uptake of cadmium and zinc by the teleost Acanthopagrus schlegelii reduced with the increase of salinity, probably due to the higher waterborne Ca2+ levels at higher salinities, because both metals use the Ca2+ uptake pathway (Zhang and Wang, 2007). Salinity does not affect LC50 of fenvalerate to bluegill, but the accumulation of this insecticide decreased with the increase of salinity (Dyer et al., 1989). – Total dissolved solids: It can change the complexing and precipitation processes of metals (CCME, 2003). The presence of suspended solids and naturally occurring dissolved substances decreases the bioavailability of cationic surfactants but not that of anionic and nonionic surfactants (Lewis, 1992). – Temperature: Besides the direct effect of temperature on the metabo- lism of ectothermic animals, it can also affect the toxicity of several pol- lutants. The effect depends on the pollutant (CCME, 2003). – Dissolved oxygen: The toxicity of pollutants can be magnified by low dissolved oxygen levels (CCME, 2003). – Dissolved organic matter (DOM): This can also affect the toxicity of metals. The major chemical components of DOM are humic substances (humic and fulvic acids). Its protective effect varies according to its ori- gin and composition. Overall, darker organic matter is expected to be more protective against metal toxicity (Al-Reasi et al., 2013). DOC also decreased uptake and toxicity of sertraline, but not of ethinyl estradiol (Alsop and Wilson, 2019). 19 General introduction to toxicology of aquatic animals
  • 35. Water quality guidelines in China are in the “Surface Water Environmental Quality Standards” GB3838-2002 (http://www.codeofchina.com/ standard/GB3838-2002.html). This guide considers that class II water is for “precious fish reserves” and up to class III water is adequate for “winter- ing grounds of fish and shrimp, migration channels, aquaculture areas of fishing waters.” The fourth amendment of this guideline used the data from native species and the assessment factor method and/or species sensitivity distribution to calculate concentrations that should result in a negligible effect on aquatic biota (Zhao et al., 2018). However, the eutrophication control management is incomplete compared to developed countries because it is based only on total nitrogen and total phosphorus values (Su et al., 2017). South Africa has a very recent and complete guideline of water quality for coastal marine waters for use to mariculture with maximum values for several pollutants, based on the values from USEPA, CCME, and EU (2013), as well as from other African countries (RSA-DEA, 2018). From Latin America, Brazil follows the resolution from the Brazilian National Environment Council (CONAMA, 2005), which has specific tables with maximum values for contaminants for fisheries and aquaculture for fresh-, brackish-, and saline waters. Mexico, on the contrary, uses only four water quality parameters (biochemical and chemical demand of oxygen, fecal coli- forms, total suspended solids) to indicate water quality (Comisión Nacional del Agua, 2018). This country has also a law that states maximum values of fats, oils, and a few metals (NOM, 1998). 2.3 Intraspecies variation of toxicity The effects of metals and pharmaceuticals in fish can be affected by sex, size, “personality” (defined as bold or shy, according to their risk-taking behaviors), and social status. For example, different responses were observed in males and females of zebrafish, Danio rerio, to cocaine, and subordinate rainbow trout are more vulnerable than dominant ones to copper and silver exposure (Demin et al., 2019). Survival of rainbow trout exposed to endo- sulfan was significantly increased with increasing fish size (Capkin et al., 2006), but the opposite was observed in those exposed to methiocarb (Altinok et al., 2006). 20 Bernardo Baldisserotto
  • 36. 2.4 Models to predict toxicity of contaminants 2.4.1 Biotic ligand model (BLM) The USEPA uses the BLM to predict dissolved metal concentrations that correspond to lethal accumulations of a metal on biotic ligands for unique water compositions, i.e., depends on the concentrations of some cations (e.g., K+ , Na+ , Ca2+ , Mg2+ , and H+ ). BLMs are computational models that determine metal speciation and predict metal toxicity to biota in aqueous systems and combine an equilibrium geochemical speciation model, a metal–organic binding model, and a toxicological model (Smith et al., 2015). This methodology was applied mainly for copper (USEPA, 2007), but there are data from the USA and Canadian species for other metals and there are also proposals to analyze the mixture of metals (Balistrieri and Mebane, 2014). The binary metal interactions tested (silver, cadmium, copper, nickel, lead, and zinc) demonstrated interactions, mostly inhibitory, nonreciprocal, and caused by silver or copper (Cr emazy et al., 2019). Nev- ertheless, BLMs must be constructed for different water qualities and species. For example, LC50 for copper in cardinal tetra Paracheirodon axelrodi from the ion-poor blackwater Rio Negro, Amazon (high level of DOC) was not predicted properly using BLM models developed using temperate DOC and temperate species (Cr emazy et al., 2016). 2.4.2 Toxicokinetic-toxicodynamic (TK-TD) models These models consider the processes that lead to toxicity at the organisms over time instead of at a certain endpoint (96h, for example), as the BLM. Nevertheless, these models use BLM-estimated binding constants cal- culated with toxicity data. The TK-TD models simulate the temporal aspects of toxicity and provide a conceptual framework to better understand the causes for variability in different species’ sensitivity to the same com- pound as well as the causes for different toxicity of different compounds to the same species (Giesy et al., 2010). Recent models can predict metal toxicity as a function of the waterborne concentrations of some cations (Feng et al., 2018a) and the mixture of metals (Gao et al., 2016). The inter- actions between metals may be time-dependent (Feng et al., 2018b). These models are also useful to extrapolate toxicity of pesticides from relatively 21 General introduction to toxicology of aquatic animals
  • 37. constant to relatively variable exposure profiles, because in the environment, they generally occur in fluctuating and highly variable patterns (Ashauer et al., 2013). 2.4.3 Principal component analysis (PCA) The PCA is a multivariate statistical procedure that uses an orthogonal trans- formation to convert a set of correlated variables into a set of values of lin- early uncorrelated variables called principal components, where the first principal component has the largest possible variance and each succeeding component in turn has the highest variance possible. Plotting the principal components can elucidate potential correlations between the set of variables (Marques et al., 2019). 2.4.4 Generalized additive modeling (GAM) The GAM approach is an extension of the generalized linear model (GLM). It is a generalized linear model with a linear predictor involving a sum of smooth functions of covariates that allows a flexible description of complex responses to environmental changes. Therefore, it can allow statistical infer- ence to nonlinear correlations between the contaminant levels and bio- marker responses. Consequently, it provides a model to predict the bioaccumulation of chemical contaminants based on biomarker responses and vice-versa, besides other influencing factors, such as seasonality and gra- dients in water chemistry parameters (Marques et al., 2019). References Al-Reasi, H.A., Wood, C.M., Smith, D.S., 2013. Characterization of freshwater natural dis- solved organic matter (DOM): mechanistic explanations for protective effects against metal toxicity and direct effects on organisms. Environ. Int. 59, 201–207. Alsop, D., Wilson, J.Y., 2019. Waterborne pharmaceutical uptake and toxicity is modified by pH and dissolved organic carbon in zebrafish. Aquat. Toxicol. 210, 11–18. Altinok, I., Capkin, E., Karahan, S., Boran, M., 2006. Effects of water quality and fish size on toxicity of methiocarb, a carbamate pesticide, to rainbow trout. Environ. Toxicol. Pharmacol. 22 (1), 20–26. Ashauer, R., Thorbek, P., Warinton, J.S., Wheeler, J.R., Maund, S., 2013. A method to predict and understand fish survival under dynamic chemical stress using standard ecotoxicity data. Environ. Toxicol. Chem. 32 (4), 954–965. Balistrieri, L.S., Mebane, C.A., 2014. Predicting the toxicity of metal mixtures. Sci. Total Environ. 466, 788–799. Blewett, T.A., Leonard, E.M., 2017. Mechanisms of nickel toxicity to fish and invertebrates in marine and estuarine waters. Environ. Pollut. 223, 311–322. Capkin, E., Altinok, I., Karahan, S., 2006. Water quality and fish size affect toxicity of endo- sulfan, an organochlorine pesticide, to rainbow trout. Chemosphere 64 (10), 1793–1800. 22 Bernardo Baldisserotto
  • 38. CCME (Canadian Council of Ministers of the Environment), 2003. Canadian Water Quality Guidelines for the Protection of Aquatic Life: Guidance on the Site-Specific Application of Water Quality Guidelines in Canada: Procedures for Deriving Numerical Water Quality Objectives. Comisión Nacional del Agua, 2018. Estadisticas del Agua en M exico. Secretarı́a de Medio Ambiente y Recursos Naturales, Ciudad de M exico. CONAMA (Conselho Nacional do Meio Ambiente), 2005. Resolução CONAMA Nº 357, from March 17th, 2005. Cr emazy, A., Wood, C.M., Smith, D.S., Ferreira, M.S., Johannsson, O.E., Giacomin, M., Val, A.L., 2016. Investigating copper toxicity in the tropical fish cardinal tetra (Paracheirodon axelrodi) in natural Amazonian waters: measurements, modeling, and real- ity. Aquat. Toxicol. 180, 353–363. Cr emazy, A., Brix, K.V., Wood, C.M., 2019. Using the biotic ligand model framework to investigate binary metal interactions on the uptake of Ag, Cd, Cu, Ni, Pb and Zn in the freshwater snail Lymnaea stagnalis. Sci. Total Environ. 647, 1611–1625. Demin, K.A., Lakstygal, A.M., Alekseeva, P.A., Sysoev, M., Abreu, M.S., Alpyshov, E.T., Serikuly, N., Wang, D.M., Wang, M.Y., Tang, Z.C., Yan, D.N., Strekalova, T.V., Vol- gin, A.D., Arnstislayskaya, T.G., Wang, J.J., Song, C., Kalueff, A.V., 2019. The role of intraspecies variation in fish neurobehavioral and neuropharmacological phenotypes in aquatic models. Aquat. Toxicol. 210, 44–55. Dyer, S.D., Coats, J.R., Bradbury, S.P., Atchison, G.J., Clark, J.M., 1989. Effects of water hardness and salinity on the acute toxicity and uptake of fenvalerate by bluegill (Lepomis macrochirus). Bull. Environ. Contam. Toxicol. 42 (3), 359–366. EU (European Union), 2013. Directive 2013/39/EU of the European Parliament and of the Council of 12 August 2013. Off. J. Eur. Union 2008, L348/84-97. Feng, J.F., Gao, Y.F., Chen, M., Xu, X., Huang, M.D., Yang, T., Chen, N., Zhu, L., 2018a. Predicting cadmium and lead toxicities in zebrafish (Danio rerio) larvae by using a toxicokinetic-toxicodynamic model that considers the effects of cations. Sci. Total Envi- ron. 625, 1584–1595. Feng, J.F., Gao, Y.F., Ji, Y.J., Zhu, L., 2018b. Quantifying the interactions among metal mixtures in toxicodynamic process with generalized linear model. J. Hazard. Mater. 345, 97–106. Gao, Y.F., Feng, J.F., Han, F., Zhu, L., 2016. Application of biotic ligand and toxicokinetic- toxicodynamic modeling to predict the accumulation and toxicity of metal mixtures to zebrafish larvae. Environ. Pollut. 213, 16–29. Giesy, J.P., Naile, J.E., Khim, J.S., Jones, P.D., Newsted, J.L., 2010. Aquatic toxicology of perfluorinated chemicals. Rev. Environ. Contam. Toxicol. 202, 1–52. Hlina, B.L., Tessier, L.R., Wilkie, M.P., 2017. Effects of water pH on the uptake and elim- ination of the piscicide, 3-trifluoromethyl-4-nitrophenol (TFM), by larval sea lamprey. Comp. Biochem. Physiol. Part C: Toxicol. Pharmacol. 200, 9–16. Lewis, M.A., 1992. The effects of mixtures and other environmental modifying factors on the toxicities of surfactants to fresh-water and marine life. Water Res. 26 (8), 1013–1023. Marques, D.D., Costa, P.G., Souza, G.M., Cardozo, J.G., Barcarolli, I.F., Bianchini, A., 2019. Selection of biochemical and physiological parameters in the croaker Micropogonias furnieri as biomarkers of chemical contamination in estuaries using a generalized additive model (GAM). Sci. Total Environ. 647, 1456–1467. NOM, 1998. Norma Oficial Mexicana NOM-002-ECOL-1996. In: Secretarı́a de Medio Ambiente, Recursos Naturales y. Pesca, Mexico. Nugegoda, D., Kibria, G., 2013. Water quality guidelines for the protection of aquatic eco- systems. In: F erard, J.-F., Blaise, C. (Eds.), Encyclopedia of Aquatic Ecotoxicology. Springer Science + Business Media, Dordrecht. https://doi.org/10.1007/978-94- 007-5704-2. 23 General introduction to toxicology of aquatic animals
  • 39. RSA-DEA (Republic of South Africa, Department of Environmental Affairs), 2018. South African Water Quality Guidelines for Coastal Marine Waters - Natural Environment and Mariculture Use. Cape Town. Smith, K.S., Balistrieri, L.S., Todd, A.S., 2015. Using biotic ligand models to predict metal toxicity in mineralized systems. Appl. Geochem. 57, 55–72. Su, J., Ji, D.F., Lin, M., Chen, Y.Q., Sun, Y.Y., Huo, S.L., Zhu, J.C., Xi, B.D., 2017. Devel- oping surface water quality standards in China. Resour. Conserv. Recycl. 117, 294–303. Tan, Q.G., Lu, S.H., Chen, R., Peng, J.H., 2019. Making acute tests more ecologically rel- evant: cadmium bioaccumulation and toxicity in an estuarine clam under various salin- ities modeled in a toxicokinetic-toxicodynamic framework. Environ. Sci. Technol. 53 (5), 2873–2880. USEPA (United States Environmental Protection Agency), 2007. Aquatic Life Ambient Freshwater Quality Criteria—Copper: 2007 Revision. U.S. Environmental Protection Agency; 2007204. USEPA (United States Environmental Protection Agency), 2019. National Recommended Water Quality Criteria—Aquatic Life Criteria Table. https://www.epa.gov/wqc/ national-recommended-water-quality-criteria-aquatic-life-criteria-table#table (Accessed April 26th, 2019). Zhang, L., Wang, W.X., 2007. Waterborne cadmium and zinc uptake in a euryhaline teleost Acanthopagrus schlegeli acclimated to different salinities. Aquat. Toxicol. 84 (2), 173–181. Zhao, X.L., Wang, H., Tang, Z., Zhao, T.H., Qin, N., Li, H.X., Wu, F.C., Giesy, J.P., 2018. Amendment of water quality standards in China: viewpoint on strategic consid- erations. Environ. Sci. Pollut. Res. 25 (4), 3078–3092. 24 Bernardo Baldisserotto
  • 40. CHAPTER THREE Antifoulants and disinfectants Samantha Eslava Martinsa,b and Camila de Martinez Gaspar Martinsb a Norwegian Institute for Water Research (NIVA), Ecotoxicology and Risk Assessment Section, Oslo, Norway b Universidade Federal do Rio Grande—FURG, Instituto de Ci^ encias Biológicas, Rio Grande/RS, Brazil 3.1 Overview In the past 50years, the primary aquatic food supply for humans chan- ged from wild-caught to production in farms. Aquaculture increased not only in the levels of production, but in the types of species cultivated, driven by high demand in a globalized environment. In 2014, the contribution of aquaculture to the production of fish for human consumption outweighed the acquisition of fish through wild fishing. Currently, the aquaculture sec- tor plays an important role in food security and livelihood, being the source of income and social development. Fish and fishery goods represent one of the most-traded segments of the world food sector, with a high international trade competition. For several countries and for numerous coastal and riv- erine regions, production of fish and fishery products is essential to their economies, accounting for more than 40% of the total value of traded com- modities in some countries, mainly islands. This represents a value 9% of global agricultural exports and 1% of world commodity trade (FAO, 2016). This impressive growth of the aquaculture sector was possible through the development of technologies that confer improved productiv- ity, allowing the production of aquatic animals in line with the increasing demand for seafood as a source of animal protein. However, major con- straints impinging aquaculture include the biofouling on aquaculture equip- ment and infrastructure, and the losses from diseases. Biofouling is of major concern in both shipping and aquaculture indus- tries. In the shipping industry, biofouling brings economic constraints because fouled organisms result in the deformation of the shape of hulls and hence the hydrodynamics of the boat, leading to an increase in the fric- tional drag and thereby fuel consumption (Abbott et al., 2000). Biofouling is a problem especially for sea cage-based finfish aquaculture where impacts are well documented. In particular, a major concern with the fouling of cages is the occlusion of netting mesh, which restricts water flow resulting in Aquaculture Toxicology © 2021 Elsevier Inc. https://doi.org/10.1016/B978-0-12-821337-7.00005-0 All rights reserved. 25
  • 41. reduced water quality (De Nys and Guenther, 2009). Another major chal- lenge is the development of effective disease treatment and prevention. Studies have shown that caged salmon may come in contact with nemato- cysts of fouling cnidarians when nets are cleaned and hydroids are released into the water (Bloecher et al., 2018; Floerl et al., 2016). Hydroid’s nema- tocysts lead to irritation and pathological damage to salmon gills and may facilitate the spread of the amoebic gill disease (AGD), an increasing threat to Atlantic salmon farming (Bloecher et al., 2018). In this sense, in order to maintain optimum culture conditions and ensure aquaculture as a profitable industry, proper husbandry techniques are mandatory, requiring that anti- fouling biocides are used to minimize biofouling. About 90% of the aquaculture occurs in developing countries, and the production losses due to disease reach up to 6 billion dollars per annum (Assefa and Abunna, 2018; Leung and Bates, 2013). The proliferation of opportunistic pathogens (bacteria, virus, fungi, or protozoa) is driven by the high density of fish stocks and the feed wastes; thus, the use of quick and effective antipathogens is necessary (Castillo-Rodal et al., 2012; Twiddy et al., 1995). Therefore, disinfection is commonly used in aquacul- ture facilities. 3.2 Definitions and uses 3.2.1 Antifoulants When an object is placed into water, microorganisms followed by algae and animals start to adhere to it. This process is termed biofouling, defined as the settlement and attachment of organisms on the external surfaces of sub- merged or semisubmerged objects (Lewis, 1998). Antifouling technologies have developed to protect structures against biofouling. Antifouling coatings have been used for many centuries. The Phoeni- cians and Carthaginians were the first to use pitch and likely copper sheeting to prevent the settlement of organisms on the bottom of wooden ships (Hellio and Yebra, 2009). From the late 18th century, the use of metals in coatings increased successfully and these compounds, particularly copper, are still incorporated into modern coatings (Dafforn et al., 2011). The effi- cacy of metals as antifoulants can be enhanced by co-biocides (or booster biocides) in the painting formulations. Such co-biocides found their market from the early 1960s when organotin-based paints were introduced as marine antifoulants and believed to be the solution to preventing biofouling 26 Samantha Eslava Martins and Camila de Martinez Gaspar Martins
  • 42. (Yebra et al., 2004). However, severe impacts on the marine environment occurred following the introduction of tributyltin (TBT), including the well-known phenomenon of imposex, which decimated the marine gastro- pod Nucella lapillus in coastal areas of Southwest England (Gibbs and Bryan, 1996). The severity of adverse ecological effects of organotin-based anti- foulants culminated in the gradual restriction until the global ban of TBT as an active ingredient in antifouling paints, in 2008 (AkzoNobel, 2000; Dafforn et al., 2011). Subsequently, organotin-free technologies flooded the paint market, turning paint formulations into a mixture of inorganic bio- cides (typically cuprous oxide) and one or more organic/organometallic co- biocides (Hellio and Yebra, 2009), such as Irgarol 1051, Diuron, DCOIT (Seanine), chlorothalonil, dichlofluanid, TCMTB, thiram, zinc pyrithione (ZnPT), and copper pyrithione (CuPT) (Castro et al., 2011; Hellio and Yebra, 2009). Such co-biocides are not expected to leach into the water bodies to trigger toxic concentrations to nontarget species (Hellio and Yebra, 2009). However, it is already known that several organisms may be very sensitive to such antifoulants, particularly during the early life stages, including farmed aquatic animals (Martins et al., 2018). 3.2.2 Disinfectants Disinfectants are used in intensive cultures, particularly in finfish and shrimp hatcheries and grow-out ponds in routine practices to disinfect culture facil- ities and equipment, to maintain hygiene throughout the production cycle, and often to treat bacterial disease outbreaks. A disinfectant is an agent that destroys infection-producing organisms. In this sense, disinfectants can act on microorganisms in two distinct ways: (1) through growth inhibition (bacteriostasis and fungistasis) or (2) through lethal action (bactericidal, fun- gicidal, or virucidal effects). The particular reason for disinfection will deter- mine the disinfection strategy used and how it should be applied. General practices of the disinfection of aquaculture systems involve the application of chemical compounds in sufficient concentrations, and for suf- ficient periods, to kill or reduce the pathogenic organisms, mainly virus and fungus, avoiding the loss of production. Essential disinfection protocols include: (1) removal of all aquatic animals (both dead and alive) from the facility; (2) a deep cleaning and washing to eliminate remaining organic mat- ter adhered to the surfaces; (3) the application of disinfectants on equipment and installations; (4) a final wash; and (5) the neutralization using chemical products, if needed. The disposal of diseased animals should not be done in 27 Antifoulants and disinfectants
  • 43. receiving waters due to the risk of contamination of wild populations or neighboring farms that use the same water supply. Therefore, the animals must be euthanized and collected by a company designed to treat or store hazardous waste. The disinfectants must be stored in such a way that they will not pose direct or indirect dangers to animal or human health and the environment (OIE - World Organisation for Animal Health, 2009). Among the most used disinfectants are formaldehyde, hydrogen perox- ide, chlorine, potassium permanganate, isopropyl alcohol, iodophors, peracetic acid and quaternary ammonium compounds (Bowker et al., 2014; Scarfe et al., 2006). In general, they are characterized by high solubility and low persistence in the aquatic environment. The efficacy and character- istics of the commonly used disinfectants are summarized in Table 3.1 (Kohn et al., 2017; Rico et al., 2012). 3.3 Mode of action 3.3.1 Antifoulants The mode of action of antifouling biocides depends on the target organisms for which the formulation was designed for. Antifouling herbicides such as Irgarol 1051 and Diuron act by inhibiting the transport of electrons during photosystem II (Hall et al., 1999), affecting photosynthetic organisms. Anti- fouling fungicides may act through different mechanisms. Chlorothalonil acts through the inhibition of glycolysis or depleting glutathione (Caux et al., 1996); despite being designed to act as a fungicide, the presence of multiple reactive electrophilic centers makes chlorothalonil extremely toxic Table 3.1 Efficacy and characteristics of commonly used disinfectants. Disinfectant Efficacy Target organism Virus Bacteria Bacterial spore Fungi Spore-forming protozoan Formaldehyde High + + + + + H2O2 High + + VA + + PAA High + + + + + Chlorine High + + VA + LA Iodophors Intermediate + + + LA QACs Low VA VA + Ozone High + + VA + LA QACs, quaternary ammonium compounds; PAA, peracetic acid; +, effective; , nonrecommended; VA, variable activity; LA, limited activity. Information on specific efficacies followed Scarfe et al. (2006) and AQUAVETPLAN (2008). 28 Samantha Eslava Martins and Camila de Martinez Gaspar Martins
  • 44. to nontarget aquatic organisms (Castro et al., 2011), causing effects in ani- mals and plants. Dichlofluanid is a potent inhibitor of fungal spore germina- tion (PPDB, 2007–2017), but its degradation products may play a major role in toxicity since dichlofluanid quickly undergoes hydrolysis in water (Schouten et al., 2005). Thiram inhibits spore germination and mycelial growth (PPDB, 2007–2017) as well as nontarget species for being a multisite inhibitor (KEMI, 2015). The organometallic antifouling biocides such as zinc pyrithione (ZnPT) and copper pyrithione (CuPT) show microbiocidal activity. There is a lack of information on the mode of action of pyrithione salts, but it has been reported that ZnPT and CuPT catalyze the electroneutral exchange of H+ and other ions with K+ across cell membranes, disrupting the proton motive force in target organisms. As a consequence, the transport of nutri- ents across membranes is impaired, leading organisms to starvation and even- tual death (KEMI, 2014). Some antifoulants act as broad-spectrum biocides with efficacy against either weeds or fungi (Fernández-Alba et al., 2002). For instance, the anti- fouling co-biocide DCOIT (4,5-dichloro-2-octyl-1,2-thiazol-3-one) reacts with the proteins of fouling specimens when they find the painting surface, breaking metabolic processes, and hence preventing the attachment of the organism to solid surfaces. Another important broad-spectrum co- biocide is TCMTB (1,3-benzothiazol-2-ylsulfanylmethyl thiocyanate) that inhibits the mitochondrial electron transport chain (Fernández-Alba et al., 2002) in a wide range of nontarget organisms. In addition to herbicides, fungicides, microbiocides, and broad-spectrum biocides, some antifoulants are categorized as “emerging compounds” because they have a relatively new use as an antifouling biocide encompassing mainly regional markets. Among them, tralopyril, medetomidine, and TPBP (pyridine-triphenylborane) should be highlighted as synthetic biocides. Tralopyril is used in coatings to enhance the antifouling efficacy of copper-free antifouling paintings by uncoupling mitochondrial oxidative phosphorylation (EU, 2014; International, 2014). Medetomidine acts through the activation of analogous octopamine leading to an anti-settling effect (EU, 2015) and is designed to protect against shell-building marine organisms. TPBP has been largely used in Japan (Mochida et al., 2012), but its mode of action is still unknown (Wendt et al., 2016). Capsaicin is a natural co-biocide extracted from chili peppers, which acts on the nervous system and also disrupts metabolism and damages membranes (Gervais et al., 2008). The capsaicin derivative nonivamide acts the same way. 29 Antifoulants and disinfectants
  • 45. 3.3.2 Disinfectants Formaldehyde is one of the most applied disinfectants in intensive aquacul- ture, being frequently used to control parasitic infections on fish and crus- tacean surfaces, and it is also used for treatment against water mold (fungus) on fish eggs (Boyd and Massaut, 1999). Although its use is encouraged in hatcheries to control the presence of “fungus,” it is not recommended for ponds because it kills algae present in pond water, reducing the production of oxygen by phytoplankton and augmenting the organic matter and decomposition (Francis-Floyd and Pouder, 1996). Formaldehyde when diluted in water form is known as formalin. Formalin may be applied as a prophylactic measure or for therapeutic purposes and is extremely effective against most protozoan parasites (Ichthyophthirius spp., Costia spp., Epistylis spp., Chilodonella spp., Scyphidia sp., and Trichodina spp.) and monogenetic trematodes (Cleidodiscus spp., Gyrodactylus spp., and Dactylogyrus spp.) (FDA, 1995; Francis-Floyd and Pouder, 1996; Shao, 2001). Due to its elec- trophilic character, formalin can react with functional groups of several bio- logical macromolecules, such as proteins, DNA and RNA, polysaccharides, and glycoproteins (Leal et al., 2018). Hydrogen peroxide (H2O2) and chlorine are potent oxidizing agents not only used as broad-spectrum disinfectants in finfish and shellfish produc- tions, but can also be used to treat fungal infections and as pesticides during the pond preparation between production cycles (Rico et al., 2012). Chlo- rine gas and powdered forms such as calcium hypochlorite and sodium hypochlorite are used to disinfect water supplies in fish and shrimp hatch- eries. They can be used in ponds after physical sediment removal, also between production cycles (AQUAVETPLAN, 2008). The chlorine and H2O2 oxidize electrons from susceptible chemical groups and become themselves reduced in the process. Oxidizing agents are usually low-molec- ular-weight compounds ready to easily pass through cell walls/membranes and then react with internal cellular components disrupting them, and lead- ing to apoptotic and necrotic cell death (Finnegan et al., 2010). At cellular level, low levels of oxidation can be reversible and prokaryotic organisms have developed many defenses against these effects. Recently, Pedersen et al. (2019) showed a relation between H2O2 decomposition and particle-associated bacterial activity, suggesting that the quantification of H2O2 in water samples can be used as a rapid and feasible indicator of micro- bial activity in fresh and saltwater aquaculture systems, ranging from pond farming to intensive recirculating systems. 30 Samantha Eslava Martins and Camila de Martinez Gaspar Martins
  • 46. Iodophors are polyvinylpyrrolidone-iodide-iodine complexes in aque- ous solution, used as disinfectants for nonhardened fish eggs to prevent spreading pathogens from the broodstock fish to the offspring (Lahnsteiner and Kletzl, 2016). Iodine acts by decreasing the oxygen requirements of aerobic microorganisms. It acts on microorganisms’ respi- ratory chain by blocking the transport of electrons through electrophilic reactions with the enzymes of the respiratory chain (Maris, 1995). The opti- mum concentration is 200mgL1 free iodine with a contact time of 2min and 100mgL1 free iodine for cleaned and dried equipment. In a nonfood- contact application, the concentration may rise to 500–800mgL1 . Iodo- phors should be used with caution because they are highly toxic to fish (Boyd and Massaut, 1999). Ammonia treatment in sanitation is a relatively new approach. In contrast to oxidants, ammonia is not consumed during the treatment. The ammonia effect on sanitation is sustained for prolonged periods, while also reducing the risk for regrowth (Kohn et al., 2017). Quaternary ammonium com- pounds (QACs) impair membrane permeability by irreversibly binding to phospholipids and proteins of the membrane. One of the commonly used products is benzalkonium chloride, applied to inhibit bacterial growth and the development of mucus in the gills of salmon (Burka et al., 1997), thereby allowing an adequate absorption of oxygen. The capability of the bacterial cell to absorb such molecules influences sensitivity. These com- pounds are used in finfish and shellfish production to treat bacterial, proto- zoan, and monogenean infections and as fungicides in shrimp hatcheries (Rico et al., 2012). Ozone is a powerful oxidizing agent widely used in aquaculture for dis- infection of pathogens and for water quality enhancements since it oxidizes organic wastes and nitrite. The oxidation of pathogens and other material by ozone occurs extremely rapidly, through reactions of molecular ozone with oxidizable compounds, and also due to the reaction of the oxidizable com- pounds with reactive oxygen species (ROS) formed by ozone decomposi- tion in water (AQUAVETPLAN, 2008; Gonçalvez and Gagnon, 2011; Scarfe et al., 2006; Spiliotopoulou et al., 2018; Summerfelt and Hochheimer, 1997; Tyrell et al., 1995). As an oxidative disinfectant, it is consumed by organic matter; thus, initial ozone concentration decays faster in waters with higher concentrations of organic matter as wastewater. For this reason, it is important to apply an ozone dose that remains in the system for enough time for the oxidation demands, whether inactivation of path- ogens or degradation of the organic matter present, without affecting farmed 31 Antifoulants and disinfectants
  • 47. species. Nevertheless, monitoring ozone performance is still a challenge (Spiliotopoulou et al., 2018). Ozonation is usually used in recirculating cul- ture systems that consume less water per kg of fish produced and allow solid removal and effluent treatment (Gonçalvez and Gagnon, 2011). The liter- ature reports a wide range of ozone dosages in recirculating systems, according to the number of animals and feed ratio (Bullock et al., 1997; Summerfelt et al., 2009; Summerfelt and Hochheimer, 1997). A drawback of ozone use is that its application is energy-consuming and requires a trained operator. Even though ozone is more reactive than chlorine in demand-free solutions toward all microorganisms, it has shown to be more efficient against viruses, but less efficient against bacteria than chlorine (Tyrell et al., 1995), although both can inactivate bacterial spores, depending on the conditions of the application and the origin of the pathogen (Broadwater et al., 1973; Rose et al., 2005; Tyrell et al., 1995). Nanomaterials are gaining space as disinfectants for aquaculture pur- poses. For example, they have been used to improve water quality in shrimp aquaculture, reducing the rate of water exchange, increasing shrimp survival rate and yield (Wen et al., 2003). Silver (Ag) nanoparticles (NPs) (nAg) are the most investigated antibacterial compounds. The nAg was used for the treatment of fungal infections in rainbow trout eggs showing an inhibitory effect on fungi growth ( Johari et al., 2015). Dananjaya et al. (2016) inves- tigated the antibacterial function of chitosan-Ag nanocomposites (CagNCs) against the fish pathogen Aliivibrio salmonicida. The CagNCs inhibited A. sal- monicida growth with a minimum inhibitory concentration (MIC) and min- imum bactericidal concentration (MBC) at 50 and 100mgL1 , respectively. Similarly, nZnO exhibited antibacterial activity disrupting bacterial cell membrane integrity, reducing cell surface hydrophobicity and down- regulating the transcription of oxidative stress-resistance genes (Pati et al., 2014). Furthermore, M€ uhling et al. (2009) showed that nTiO2 and nAg reduced the buildup of bacteria in estuarine water (). Another disinfectant that has been recognized to be suitable for aquacul- ture is peracetic acid (PAA) which is considered an alternative sanitizer to formaldehyde. PAA is a highly reactive peroxygen with widespread antimi- crobial effects (Liu et al., 2015, 2016; Pedersen et al., 2009, 2013). It degrades entirely within several hours after application, resulting in trace concentration residuals that are not readily measured (Pedersen et al., 2009). The test kits are not sensitive enough to analyze PAA at low ranges (below 0.2ppm). Only a few studies have described analytical measurement of the commercial PAA compound (Pedersen et al., 2013). In this sense, 32 Samantha Eslava Martins and Camila de Martinez Gaspar Martins