Article

Aquaculture Production and Biodiversity Conservation

Authors:
To read the full-text of this research, you can request a copy directly from the author.

Abstract

This overview examines the status and trends of seafood production, and the positive and negative impacts of aquaculture on biodiversity conservation. Capture fisheries have been stabilized at about 90 million metric tons since the late 1980s, whereas aquaculture increased from 12 million metric tons in 1985 to 45 million metric tons by 2004. Aquaculture includes species at any trophic level that are grown for domestic consumption or export. Aquaculture has some positive impacts on biodiversity; for example, cultured seafood can reduce pressure on overexploited wild stocks, stocked organisms may enhance depleted stocks, aquaculture often boosts natural production and species diversity, and employment in aquaculture may replace more destructive resource uses. On the negative side, species that escape from aquaculture can become invasive in areas where they are nonnative, effluents from aquaculture can cause eutrophication, ecologically sensitive land may be converted for aquaculture use, aquaculture species may consume increasingly scarce fish meal, and aquaculture species may transmit diseases to wild fish. Most likely, aquaculture will continue to grow at significant rates through 2025, and will remain the most rapidly increasing food production system. © 2009 by American Institute of Biological Sciences. All rights reserved.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the author.

... Widespread use of chemicals, drugs, and antibiotics is an example of a disturbance to microbiota, and is a rising concern in aquaculture [ [35][36][37]. With recent expansion and rapid growth in demand for aquaculture products in conservation and food production [38], chemical and antibiotic applications are increasingly used in aquaculture to control pathogens [39,40]. While short-term benefits are often realized, there is potential for damaging impacts of these practices, including disruption of co-adapted microbial communities. ...
... While short-term benefits are often realized, there is potential for damaging impacts of these practices, including disruption of co-adapted microbial communities. Further, large amounts of chemotherapeutants are passed into aquatic environments [29][30][31][32][33][34][35][36][37][38][39][40][41], including reduction in abundance of susceptible members of microbial communities. ...
Article
Full-text available
Antibiotics, drugs, and chemicals (collectively referred to as chemotherapeutants) are widely embraced in fish aquaculture as important tools to control or prevent disease outbreaks. Potential negative effects include changes in microbial community composition and diversity during early life stages, which can reverse the beneficial roles of gut microbiota for the maintenance of host physiological processes and homeostatic regulation. We characterized the gut microbial community composition and diversity of an ecologically and economically important fish species, the lake sturgeon (Acipenser fulvescens), during the early larval period in response to weekly treatments using chemotherapeutants commonly used in aquaculture (chloramine-T, hydrogen peroxide, and NaCl2 followed by hydrogen peroxide) relative to untreated controls. The effects of founding microbial community origin (wild stream vs. hatchery water) were also evaluated. Gut communities were quantified using massively parallel next generation sequencing based on the V4 region of the 16S rRNA gene. Members of the phylum Firmicutes (principally unclassified Clostridiales and Clostridium_sensu_stricto) and Proteobacteria were the dominant taxa in all gut samples regardless of treatment. The egg incubation environment (origin) and its interaction with chemotherapeutant treatment were significantly associated with indices of microbial taxonomic diversity. We observed large variation in the beta diversity of lake sturgeon gut microbiota between larvae from eggs incubated in hatchery and wild (stream) origins based on nonmetric dimensional scaling (NMDS). Permutational ANOVA indicated the effects of chemotherapeutic treatments on gut microbial community composition were dependent on the initial source of the founding microbial community. Influences of microbiota colonization during early ontogenetic stages and the resilience of gut microbiota to topical chemotherapeutic treatments are discussed.
... There is a growing trend of converting agricultural lands into aquaculture ponds and an opposite trend has been noticed for agricultural lands. There is a lost-lasting concern over the actual or potential impacts of certain aquaculture practices on biodiversity as such practices may be harmful to biodiversity (Diana 2009). This has been identified, at least speculated, by many researchers and organisations working with the environment. ...
... The impacts of aquaculture activities on local biodi-versity are usually negative; in some cases it may be neutral but rarely positive (Beveridge et al. 1997). Several negative impacts of aquaculture on biodiversity can be identified (Diana 2009). These include unwanted escape of aquaculture species capable of being invasive; interactions between effluents from aquaculture facilities causing eutrophication and aquatic fauna in receiving waters; expansion of aquaculture in important habitats including mangroves and wetlands; impacts on other aquatic resources for aquaculture inputs such as fish meal preparation can lead to overexploitation of required stocks; transmission of disease causing agents from aquaculture species to wild stocks; possible genetic degradation of natural stocks from escaped hatchery-bred species; increasing killing of fish predators such as birds near aquaculture farms; increasing use of antibiotic and hormone. ...
Article
Full-text available
Despite positive role of aquaculture in food production, the practice may impact the environment negatively and it is difficult to quantify the loss. In this study, we assessed land use changes in four important wetlands (Hardoho Beel, Angrar Beel, Shaoil Beel and Gopalpur Beel) of Bangladesh through analysis of historical satellite images (1990 – 2020) to show how expansion of aquaculture activities threatens the existence of freshwater wetlands. Since 1990, the water area of all four wetlands decreased significantly over time (all p < 0.001). Mean yearly loss of 47.9 ± 79.3 ha, 99.2 ± 185.5 ha, 51.2 ± 61.9 ha and 2.6 ± 4.7 ha were recorded for Hardoho Beel, Angrar Beel, Shaoil Beel and Gopalpur Beel respectively. A decreasing trend in wetland area was recorded in all wetlands, primarily due to excavation of aquaculture ponds. In 2020, aquaculture ponds represented 72% of the core wetland areas. Two wetlands (Hardoho and Gopalpur) were almost totally lost and converted to aquaculture ponds and agricultural lands. This study concludes that the existence of freshwater wetlands in Bangladesh is at stake and recommends further studies to determine its impacts on people's livelihood and biodiversity.
... As a result the impact of aquaculture on the environment and the understanding of its sustainability have been a concern since the early 1990s (Folke and Kautsky, 1992;Naylor et al., 2000;Perdikaris et al., 2016). However, aquaculture continues to be associated with a series of impacts on the environment (Naylor et al., 2000;Diana, 2009;Ottinger et al., 2016). The growth of aquaculture production leads to a more significant environmental burden, such as eutrophication of water bodies, the entry of invasive species, parasites and diseases for wild populations, greater use of antibiotics, and effluent emissions contribute to climate change (Henriksson et al., 2015a,b). ...
... Finally, as the level of farming intensity accelerates, the production per unit area increases considerably, and in some cases, the feed-conversion efficiency decreases, costs rise, and more waste is generated. In developing countries, aquaculture mostly takes place in both semiintensive and intensive systems, while it remains intensive in developed countries (Diana, 2009). ...
Chapter
This chapter deals with the life cycle impact of industrial aquaculture systems. The capture fishery production has overexploited the wild-fish stocks, and the global demand for aquatic products is still increasing. Industrial aquaculture systems, such as marine net-pen, have a life cycle impact, most of which is due to the energy needed to produce feed and to the marine biotic resource overexploitation. In this regard, it should be worth estimating the impacts using a life cycle assessment. This method, which is often referred to as “cradle to grave” analysis, was already used to evaluate many aquaculture systems. Several studies reported that improving feeding practices may mitigate the environmental footprint of animal production. In this context, improving the precision in nutrition and feeding is a highly promising avenue for increasing the resource-use efficiency (e.g., nutrients) compared to conventional feeding programs.
... The opponents of spawner harvesting, in addition to arguing that these treatments are neither effective or economically justified, give specific examples of failed fish stocking campaigns, and often mention hazards to biodiversity or changes to the natural environments themselves, that can result from irresponsible or inappropriate stocking (Cambray 2003, Johnson et al. 2009. On the other hand, fish stocking promoters (Mickiewicz 2016) claim that the harvesting of spawners is a key element of fisheries management, and that one of the most important goals of these measures is to maintain or increase the size of economically valuable fish species populations to a level that makes the fisheries management economically viable (Mickiewicz and Wo³os 2011, Trella and Wo³os 2021a and ecologically important, particularly in terms of biodiversity preservation (Diana 2009). In addition, the entities authorised to fishing are required to carry out fish stocking operations (Mickiewicz 2016), therefore, in contrast to angling organisation in e.g. ...
... Efektywna gospodarka zarybieniowa jest kluczowym elementem gospodarki rybackiej, gdy¿ jednym z jej najwa¿niejszych celów jest utrzymanie lub zwiêkszenie liczebnooeci populacji cennych gospodarczo gatunków ryb do poziomu, który sprawia, ¿e prowadzenie takiej gospodarki jest op³acalne ekonomicznie (Mickiewicz i Wo³os 2011, Zakêoe i Demska-Zakêoe 2011. Jednak zarybienia s¹ te¿ wa¿ne z ekologicznego punktu widzenia, szczególnie w zakresie zachowania bioró¿norodnooeci, jest to równie¿ element akwakultury zachowawczej (Diana 2009). Wylêgarnictwo i larwikultura oraz póŸniejsze podchowanie narybku to zadania, którego podejmuj¹ siê u¿ytkownicy wód zarz¹dzaj¹cy obwodami rybackimi albo wyspecjalizowane ooerodki zarybieniowe, które tworz¹ bardzo prê¿n¹ w naszym kraju bran¿ê, o czym oewiadczy teren województwa warmiñsko-mazurskiego, gdzie w 2009 roku dzia³a³o 27 obiektów wylêgarniczo-podchowalniczych, w których w latach 2000-2008 oerednio ponad 50% inkubowanej ikry, stanowi³a ikra szczupaka (Zakêoe i Jarmo³owicz 2009 ...
Thesis
Full-text available
(PL) Zmiany klimatyczne wywierają coraz większy wpływ na globalną, państwową i regionalną gospodarkę, gdyż pośrednio i bezpośrednio oddziałują na tak ważne segmenty, jak produktywność i efektywność rolnictwa czy energetyki, ale również na ochronę środowiska czy bezpieczeństwo ludności. Wpływ zmian klimatu na ekosystemy wodne i zasoby ryb stanowi przedmiot coraz liczniejszych badań naukowych prowadzonych w różnych częściach świata. łagodzenie zmian klimatu i adaptacja do jego zmian to kluczowe wyzwania, jakim musi stawić czoła w XXI w. cała branża rybacka. Gospodarkę rybacką na śródlądziu, w odróżnieniu od rybołówstwa morskiego, można nazwać niskoemisyjną, jednak globalne zmiany na pewno wpłyną i już wpływają na warunki jej prowadzenia. Do wdrożenia właściwych strategii zarządzania i zrównoważonej eksploatacji zasobów rybnych niezbędna jest podstawowa wiedza na temat zarządzanych wód. Gospodarka rybacka jest dość złożoną formą działalności zbudowaną z wielu elementów, takich jak: rybołówstwo komercyjne i rekreacyjne (wędkarstwo) oraz właściwie prowadzona gospodarka zarybieniowa. Gospodarka zarybieniowa musi spełniać trzy podstawowe warunki: musi być ekologicznie dopuszczalna (bezpieczna), a jednocześnie pożądana społecznie i ekonomicznie wykonalna. Efektywna gospodarka zarybieniowa jest kluczowym elementem gospodarki rybackiej, gdyż jednym z jej najważniejszych celów jest utrzymanie lub zwiększenie liczebności populacji cennych gospodarczo gatunków ryb do poziomu, który sprawia, że prowadzenie takiej gospodarki jest opłacalne ekonomicznie. Omawiana dysertacja nie bazuje na skomplikowanych modelach klimatycznych, ale na informacjach uzyskanych od rybackich użytkowników wód, którzy z racji specyfiki swego zawodu są z jednej strony najbliżej środowiska wodnego i jego zmian (a zatem pełnoprawnymi ich obserwatorami), a z drugiej żywotnie zainteresowani powstrzymaniem (jeśli takie występują) negatywnych skutków zmian klimatu na ichtiofaunę i prowadzenie gospodarki rybackiej. Odpowiednie zarządzanie zasobami ichtiofauny, czyli wyważona eksploatacja, zarówno w sposób komercyjny, jak i wędkarski oraz racjonalna gospodarka zarybieniowa, wraz z odbudową środowiska naturalnego, są głównymi zadaniami zrównoważonej gospodarki rybackiej prowadzonej w wodach śródlądowych. Zasadniczym celem prac badawczych składających się na przedmiotową rozprawę doktorską było określenie wpływu zmian klimatycznych i gospodarki zarybieniowej na efektywność gospodarki rybackiej. Prace badawcze podzielono ze względu na poruszoną tematykę. Pierwszy temat, z ogólnym tytułem wpływ zmian klimatycznych na gospodarkę rybacką, analizy przeprowadzono w oparciu o zebrane szczegółowe ankiety, wyplenione przez użytkowników, którzy prowadzą gospodarkę rybacką i wędkarską na jeziorach, oraz użytkowników, którzy prowadzą gospodarkę w zbiornikach zaporowych; w drugim temacie gospodarka zarybieniowa – problematyka odłowu tarlaków, badania przeprowadzono w oparciu o ankiety, które uzyskano od użytkowników rybackich, którzy prowadzą gospodarkę rybacką i wędkarską w jeziorach; w trzecim temacie wielkość i wartość odłowów rybackich oraz zarybień szczupakiem, wykorzystano informacje na temat podstawowych parametrów charakteryzujących analizowane podmioty oraz wielkości i wartości odłowów szczupaka, oraz ilości, rodzaju materiału zarybieniowego i jego wartości, liczby podmiotów zarybiających szczupakiem, wielkości zarybianej powierzchni, całkowitej wartości zarybień wszystkimi gatunkami ryb oraz wielkości i wartości złowionych tarlaków wszystkich gatunków ryb, zebrane przy pomocy kwestionariuszy statystycznych RRW-23 od podmiotów uprawnionych do rybactwa na wodach powierzchniowych płynących (jeziora, cieki, zbiorniki zaporowe); czwarty temat wielkości i wybrane cechy połowów rybackich i wędkarskich szczupaka w perspektywie długoterminowej, opisany został na bazie wieloletnich doświadczeń i badań prowadzonych w Zakładzie Bioekonomiki Rybactwa Instytutu Rybactwa Śródlądowego im. Stanisława Sakowicza; piąty temat ocena efektywności zarybień szczupakiem, podzielony został na dwa podtematy: a) ocena efektywności zarybień szczupakiem w jeziorach, w której analizę oparto na materiałach uzyskanych w Gospodarstwie Jeziorowym Sp. z o.o. w Ełku oraz wynikach badań cen ryb i materiału zarybieniowego, b) ocena efektywności zarybień szczupakiem w zbiornikach zaporowych, gdzie podmiotem uprawnionym do rybactwa w badanych zbiornikach zaporowych jest Okręg PZW w Katowicach. Zbiorniki te były systematycznie zarybiane szczupakiem, i mogły posłużyć jako przykład możliwości przeprowadzenia oceny efektywności zarybień przy wykorzystaniu metod statystycznych oraz informacji o zarejestrowanych przez wędkarzy odłowach i przeprowadzonych zarybieniach. Na podstawie uzyskanych wyników stwierdzono, że uprawnieni do rybactwa w znacznej większości zauważyli w ostatnich latach wpływ zmian klimatycznych na ichtiofaunę i rybackie gospodarowanie; gatunkiem, który według użytkowników rybackich najbardziej narażony jest na zmiany klimatyczne jest szczupak; zmiany klimatyczne najbardziej wpływają na wielkości połowów węgorza; ankietowani najbardziej obawiają się zjawiska dłuższego okresu przebywania kormoranów na akwenach; za najistotniejszy wpływ zmian klimatu na wybrane parametry hydrologiczne jezior respondenci wybrali niskie poziomy i wahania poziomów wód; użytkownicy zbiorników zaporowych uznali, że największy wpływ na populacje ryb nie mają zachodzące zmiany klimatyczne, ale sam zbiornik, który utrudnia migracje ryb; badanych respondentów charakteryzuje wysoka niechęć do potencjalnych zmian i innowacji w kwestii odłowu tarlaków; ilość wylęgu wprowadzana do wód obwodów rybackich w ostatnich latach wykazywała bardzo wyraźną tendencję wzrostową; w skali całego kraju odłowy wędkarskie szczupaka były 8-krotnie wyższe niż rybackie; zastosowanie rachunku korelacji wykazało, że wzrost dawek zarybieniowych szczupaka powodował wyraźne zwiększenie poziomu odłowów, ale po przekroczeniu granicznego poziomu zarybień nie następował wzrost, tylko nieznaczny spadek wydajności; w badaniach efektywności zarybień szczupakiem w jeziorach ełckich nie wykazano statystycznie istotnego związku z zarybieniami, lecz wykazano ekonomizację (dążenie do podnoszenia ekonomiczności) w tym zakresie gospodarowania szczupakiem. Określenie wpływu zmian klimatycznych, ale także gospodarki zarybieniowej na efektywność gospodarki rybackiej nie należy do zadań prostych, gdyż w odróżnieniu od badań laboratoryjnych, gdzie efekty badań widoczne są w stosunkowo krótkim czasie, w przypadku poruszanych w pracy doktorskiej zagadnień na efekty trzeba czekać dość długo. Z tego powodu zdecydowano się skorzystać z wieloletnich obserwacji uprawnionych do rybactwa, których praca zawodowa na tak różnych akwenach trwa czasem dłużej niż 30 lat, i warto podkreślić, jak wartościowe były te informacje. Przeprowadzone w ramach dysertacji doktorskiej badania, wobec znacznej liczby, złożoności i kompleksowego oddziaływania czynników wpływających na prowadzenie gospodarki rybackiej, nie pozwoliły na zidentyfikowanie wszystkich z nich, a tym bardziej na skwantyfikowanie ich wpływu na efektywność tej gospodarki. W związku z tymi ograniczeniami stworzono uproszczony schemat, na którym przedstawiono te z grupy czterech najważniejszych, a nauce znanych, elementów systemu (tj. przyrodniczych, społecznych, ekonomicznych i legislacyjnych), na których wpływ dzięki przeprowadzonym badaniom przynajmniej udało się zidentyfikować i wyrazić w formie pewników bądź wpływów bardzo prawdopodobnych. Wyniki tych badań mogą służyć jako odniesienie do przyszłych norm prowadzenia racjonalnej gospodarki rybackiej na wodach Skarbu Państwa i wprowadzania odpowiednich regulacji prawnych, które bardziej odpowiednio przygotują gospodarstwa rybackie na przyszłe, niestety nieuniknione, zmiany klimatyczne. (EN) Climate change is having an increasing impact on global, national and regional economies, as it directly and indirectly affects such important segments as agricultural or energy productivity and efficiency, but also on environmental protection or human security. The impact of climate change on aquatic ecosystems and fish resources is the subject of increasing scientific research in various parts of the world. Climate change mitigation and adaptation are the key challenges facing the entire fishing sector in the 21st century. Inland, as opposed to marine, fisheries management can be called low-carbon, but global changes will certainly affect and are already affecting the conditions under which it is conducted. Basic understanding of managed waters is required to implement appropriate management strategies and sustainable exploitation of fish resources. As a fisheries sector, fisheries management is a rather complex activity comprising a number of elements, such as commercial and recreational fishing (angling) and properly conducted stocking management. Stocking management must meet three fundamental conditions: it must be ecologically acceptable (safe), and at the same time socially desirable and economically viable. Effective stocking management is a critical component of fisheries management, since one of its most important objectives is to preserve or increase the population of economically valuable fish species to a level that makes such management economically profitable. This dissertation is not based on complex climate models, but on information collected from fisheries managers who, due to the specifics of their profession, are on the one hand closest to the water environment and its changes (and therefore rightful observers), and on the other are vitally interested in halting (if any) negative effects of climate change on fish fauna and fisheries management. Proper management of ichthyofauna resources, i.e. balanced exploitation, both commercially and by anglers, and rational stocking management, together with restoration of the natural environment, are the main objectives of sustainable fisheries management in inland waters. The primary aim of the research work for this dissertation was to determine the impact of climate change and stocking management on fisheries management efficiency. The study was divided according to the subject areas investigated. The first topic, with the general title of the influence of climate change on fisheries management, was analysed on the basis of detailed questionnaires collected from users who run fishing and angling management in lakes and from users who manage in dam reservoirs; the second topic, stocking management – the problem of spawners’ harvest, was based on questionnaires obtained from fishing users who manage fishing and angling in lakes; in the third topic, the volume and value of fishing catches and pike stocking, information was used on basic parameters characterizing the analysed fishing entities and the volume and value of pike catches, data on the quantity, type and value of stocking material, the number of entities stocking pike, the size of the stocked area, the total value of stocking with all fish species and the size and value of harvested spawners of all fish species; these data were collected using statistical questionnaires RRW-23 from entities authorised to fishing on flowing surface waters (lakes, rivers, dam reservoirs); the fourth topic, the size and selected characteristics of pike catches in the long-term perspective, was described on the basis of years of experience and research activities at the Department of Fishery Bioeconomics of The Stanisław Sakowicz Inland Fisheries Institute; the fifth topic, assessment of the effectiveness of pike stocking, was divided into two sub-themes: a) assessment of the effectiveness of pike stocking in lakes, in which the analysis was based on materials obtained from Gospodarstwo Jeziorowe Ltd in Ełk and resultsof studies on prices of fish and stocking material, b) evaluation of effectiveness of pike stocking in dam reservoirs, where the entity authorised to fishing in the investigated dam reservoirs is the Katowice District of Polish Angling Association. These dams were systematically stocked with pike and could serve as an example of how to assess stocking efficiency using statistical methods and information on anglers’ records of catches and stocking events. From the results, it was concluded that: fishery users have overwhelmingly reported the impact of climate change on ichthyofauna and fishery management in recent years; the species most affected by climate change according to fishing users is pike; climate change is having the highest impact on eel catches; respondents are most concerned about the longer residence time of cormorants in water bodies; respondents selected low water levels and fluctuations in water levels as the most important influence of climate change on selected hydrological parameters of lakes; in the opinion of dam users, the greatest impact on fish populations is not caused by climate change, but by the dam itself, which makes fish migration difficult; respondents are strongly averse to potential changes and innovations in the harvesting of spawners; the amount of pike stocking with larvae to the waters of the fishing zones in recent years has shown a very clear upward trend; at the scale of the whole country, anglers’ catches of pike were eightfold higher than commercial ones; application of the correlation calculus showed that an increase in the stocking rate of pike resulted in a clear increase in the level of catches, but when the limit of the stocking rate was exceeded there was no increase, only a slight decrease in the catch efficiency; studies on efficiency of pike stocking in Ełk lakes did not show statistically significant correlation with stocking rates, but showed economization (attempt to increase economy) in this area of pike management. Identifying the impact of climate change and stocking management on the effectiveness of fisheries management is not an easy task, because unlike in the case of laboratory studies, where the effects of research are visible in a relatively short period of time, in contrast to the issues discussed in the dissertation, one has to wait rather long for results. For this reason, it was necessary to make use of the many years of observations of authorised fisheries managers, whose professional work in such various waters sometimes lasted more than 30 years, and it is worth mentioning how valuable this information has been. The studies conducted as part of the dissertation, in the light of the large number, complexity and comprehensive impact of factors influencing fisheries management, did not make it possible to identify all of them, let alone quantify their influence on the effectiveness of fisheries management. In view of these limitations, a simplified diagram was created to present those of the four most important system elements known to science (i.e. natural, social, economic and law) whose impact could at least be identified and described as certainties or very likely. The results of this studies can serve as a reference for future standards of rational fishery management in waters belonging to the State Treasury and the introduction of appropriate legal regulations, which will more adequately prepare fishing entities for future, unfortunately unavoidable upcoming climate changes.
... According to Diana (2009), no food production system now in use is truly sustainable from an energy and biodiversity perspective-all food production systems generate wastes, require energy, use water, and change land cover. Aquaculture has some positive impacts on biodiversity as reduction pressure on overexploited wild stocks, boosts natural production and species diversity, replacing more destructive resource uses. ...
... Aquaculture has some positive impacts on biodiversity as reduction pressure on overexploited wild stocks, boosts natural production and species diversity, replacing more destructive resource uses. On the negative side, species that escape from aquaculture can become invasive in areas where they are nonnative and effluents from aquaculture can cause eutrophication and may transmit diseases to wild species as for example observed in USA (Diana 2009) and Thailand (Sampantamit et al. 2020). Pollution of local waters that supply aquaculture systems threatens aquaculture itself as well as biodiversity. ...
Article
Full-text available
This study aimed to determine artificial semi-dry wetlands’ performance to wastewater treatment from fish farming and Lactuca sativa production in an aquaponics system. This trial model observed the effects of different stocking biomass on the growth rate of Colossoma macropomum and yield of two L. sativa varieties. A factorial design consisting of three fish density treatments in quadruplicate and two Lettuces variety was used. Nine hundred and sixty fingerlings with 8.35 ± 0.91 g were stocked at three stocking biomass treatments in quadruplicate: 40 fingerlings or 334 g m−3; 80 fingerlings 668 g m−3; 120 fingerlings or 1002 g m−3. Delice American Lettuce and Purple Crested Lettuce were cultured in the semi-dry wetlands. The final mass (g), consumed food, feed conversion ratio, and yield of fingerling were statistically different between the tested densities, but survival did not. The artificial semi-dry wetlands were efficient on water treatment and the recovery of nutrients in all fish densities trials, and it has potential as support for lettuce production. The recovery of nutrients was shown on the increment of the number of leaves, total fresh mass (g), and lettuces yield by area (kg m−2) in both varieties of plants tested. Precocious flowering in 30% of lettuce varieties, incidence of mealybug and whitefly, temperature and deficiency of calcium and magnesium were factors that may have compromised the full lettuce development. The aquaponics system efficiently treated the fish effluent at the densities tested, being appropriate for fish farming and lettuces production.
... Gausen and Moen, 1991;Jayanthi et al., 2018;Ottinger et al., 2016). It affects local ecosystems, for example due to nutrients emissions in surrounding waters or interactions with local environments, and contributes to global environmental problems such as climate change and fish stock depletion, through its usage of fishmeal and fish oil (FMFO) in the feed (Diana, 2009;Naylor et al., 2000). Environmental implications of new policies should therefore be assessed and put in perspective with existing environmental regulations beforehand (Hall et al., 2011). ...
... Additionally, even though many impact categories decrease through time with the introduction of that Feed option, it has no mitigation effect on eutrophication. This impact is often considered one of the most important when it comes to aquaculture systems (Diana, 2009). The most efficient way to reduce eutrophication is to reduce the FCR, hence reducing at the origin the emissions of uneaten feed and feces. ...
Article
To address global food demand and sustainability challenges, aquaculture has appeared as an essential element in food systems, and an increasing number of national aquaculture policies have emerged over the past decades. However, several of these policies have failed because of an often-argued inability to anticipate their far-reaching implications on environmental and socio-economic variables. To tackle this gap, we propose a step-wise framework to assess the national environmental impacts from aquaculture industries with a prospective and systemic approach. Starting from identifying policy-based national targets, the methodology relies on economic equilibrium modeling to develop realistic future-oriented scenarios of the aquaculture sector, and couples them with life cycle assessment principles. To evidence its operability, we apply the framework to two distinct case countries: Norway and Singapore. Beyond our key findings from the analyses of the policies in both countries, we observed that feed production and usage are important drivers of impacts, hence calling for new and more environmentally-friendly feed options. Our results additionally show that the development of aquaculture following existing governmental policies may not directly reduce greenhouse gases emissions and, hence, not support climate change mitigation objectives. These findings should however be cautioned as potential shifts of diets due to the increasing seafood availability might occur, leading to indirect environmental benefits. We therefore advocate the further expansion of our framework to cover the entire food system, so it can integrate such indirect effects. Meanwhile, we recommend its interim application to support policy-making and help move towards more environmentally sustainable aquaculture systems.
... Per capita seafood consumption is expected to continue to increase by 1.5 kg per year by 2025 (Diana, 2009). ...
... Population growth and increasing per capita consumption suggest that farmed seafood products will gradually become more important as an additional food source, and that aquaculture will play a vital role as natural fish stocks continue to decline (Diana, 2009;Beneet al. 2016). ...
Article
Full-text available
For the first time in Iraq, an economic feasibility study is being conducted for establishing a shrimp farm in Basra-southern Iraq. The expected results were according to the situation in terms of prices and costs. Through a culture density of 80 larvae / m² with a survival rate of 50%, the productivity of one acre was evaluated with no more than 1000 kg of shrimp / 0.25 hectare, and the amount of feed consumed was one ton during the annual crop (six months, i.e. from April to October), and the marketing value of each acre was not Less than 8 million Iraqi dinars (32 million hectares of production), considering the price of one kilo of shrimp is 8 thousand dinars, and the weight of one shrimp reaches 10 grams during. After calculating the costs of establishing the farm (one hectare) for the first year, 20 million, while in the second year it needed only 10 million. The sole dependence on the catch of shrimp to meet the juvenile provision of Metapenaeusaffinis and Penaeussemisulcatus juvenile shrimp, and perhaps freshwater shrimp can benefit from Macrobrachiumnipponense found in marine and river waters.
... Freshwater aquaculture generates thousands of direct and indirect employees, and it is recognized as an alternative food source with the potential to reduce pressure on wild stocks (Diana, 2009;Gutiérrez et al., 2020). However, depending on the type of system, freshwater aquaculture is also linked to a wide spectrum of environmental issues, such as habitat alteration, the escape of exotic species and competition with native species, water pollution through nitrogen and phosphorus release in superficial water bodies, that may subsequently trigger eutrophication (Diana, 2009), biotic depletion, fish diseases and parasites and greenhouse gas (GHG) emissions from aquafeed production, among others . ...
... Freshwater aquaculture generates thousands of direct and indirect employees, and it is recognized as an alternative food source with the potential to reduce pressure on wild stocks (Diana, 2009;Gutiérrez et al., 2020). However, depending on the type of system, freshwater aquaculture is also linked to a wide spectrum of environmental issues, such as habitat alteration, the escape of exotic species and competition with native species, water pollution through nitrogen and phosphorus release in superficial water bodies, that may subsequently trigger eutrophication (Diana, 2009), biotic depletion, fish diseases and parasites and greenhouse gas (GHG) emissions from aquafeed production, among others . Furthermore, veterinary drugs and antibiotics from aquaculture systems can also be discharged to the environment, causing toxic effects in aquatic biodiversity, antibiotic accumulation and antibiotic resistance (Lulijwa et al., 2020). ...
Article
Aquaculture is an increasingly important supplier of food worldwide. However, due to its high dependence on agricultural and fishing resources, its growth is constantly constrained by environmental impacts beyond aquaculture production systems. Within the European Union, Spain accounts for approximately 25 % of total aquaculture production, which implies that environmental impacts in rivers and marine ecosystems must be monitored to understand the role of aquaculture systems. While studies on the environmental performance mussels or turbot production have been reported in the literature, Spanish rainbow trout (Oncorhynchus mykiss) has not received much attention despite its relative importance. In this sense, a Life Cycle Assessment (LCA) study of rainbow trout produced in a medium-sized plant in Galicia (NW Spain) was carried out in the present study. The study considered the production of round weight trout, as well as some commonly produced processed products, including filleting. The life cycle modelling included a high level of primary data in the foreground system. In addition to the widely considered environmental impact categories for this activity (global warming potential, terrestrial acidification and freshwater eutrophication), the recent proposed antibiotic resistance (ABR) enrichment impact category was included to explore the potential impact of antibiotic release in freshwater microbiota. The results highlighted the high contribution of aquafeed to most impact categories, due to upstream agricultural and fishing processes, whereas farm operation was responsible for the larger part of the impact in freshwater eutrophication, mainly due to direct emissions of nutrients from fish feeding. Amoxicillin release to recipient water bodies was the main driver to the ABR enrichment category. In contrast, the processing phase (i.e., gutting, freezing and packaging) showed low environmental burdens. In order to improve the environmental performance of the rainbow trout production system, decreasing the feed conversion ratio (FCR), shifting to renewable energy, using low environmental burden ingredients in aquafeed, and alternatives to control of diseases without antibiotics could be considered.
... Production increased more than 6-fold from 1990 to 2018, and cultured aquatic animal products (including fish, mollusks, and crustaceans) currently account for >8% of the global human population's animal protein intake (FAO, 2020). Therefore, the aquaculture industry is important for maintaining global food security (Naylor et al., 2021), as well as for conserving biodiversity in a way that reduces the consumption of overexploited wildlife resources (Diana, 2009). Aquafarms have also become alternative habitats for a variety of waterbirds, a group affected by severe habitat loss in part due to the conversion of natural habitat to agriculture, including aquaculture (Kirby et al., 2008). ...
Article
The global aquaculture industry has expanded rapidly and is increasingly important for maintaining food security while also providing alternative artificial habitats for many waterbirds. Clarifying how waterbirds use aquafarms and how aquafarm use affects waterbird population maintenance can be useful for improving management of the artificial landscape that can also provide waterbird habitat. Here, we investigated aquafarm use by waterbirds in China, the world's largest producer of aquaculture products, supported by literature review and questionnaire survey. We used Bayesian phylogenetic generalized linear mixed models to analyze the relationship between the degree of aquafarm use and population trends of waterbirds. The results showed that 69% of waterbird species in China have been recorded at aquafarms. Approximately one‐quarter of all waterbird species and about the same proportion of threatened species were found to forage at aquafarms, consuming either cultured aquatic products or other food types. In general, species with a high degree of aquafarm use were unlikely to exhibit a population decline over the past two decades, when rapid loss of natural habitats occurred in China. This relationship was not detected in threatened species, despite there being no significant difference in the degree of aquafarm use between threatened and non‐threatened species. Our study suggests that the large and expanding aquaculture industry is important for maintaining waterbird populations in China. However, aquafarms are not a replacement for natural habitats, because threatened species benefit less from aquafarm use. Given that aquafarms often come at the expense of natural wetlands, the degree to which aquafarms compensate for natural habitat loss probably depends on the quality of aquafarm habitat. We recommend an integrated ecological and economic analysis for formulating management policies that help conserve wildlife within the constraints and opportunities associated with maintaining human livelihoods. This article is protected by copyright. All rights reserved
... For example, carps (common carp, silver carp, grass carp) have been widely introduced across the region but are not recognised as invasive species in the same way as they are in countries such as Australia and the United States of America. Potential impacts might be escapes of invasive species, pollution from aquaculture, conversion of sensitive land areas, overexploitation of resources (for example for fishmeal), spread of disease from captive to wild stocks, alteration of the genetic composition of wild stocks through inter-breeding with escaped farmed fish, predator mortality (for example culling birds) and harmful release of chemicals (for example antibiotics and hormones) into the environment (Diana, 2009). ...
... On one hand, it is obvious that the current level of consumption cannot be supported by wild catch alone. On the other hand, the increase of aquaculture production, at an average of 5.3% per year in the period (FAO, 2020, raises concerns about its negative impact on the ecosystem, such as discharges of untreated effluents, spreading of aquatic pathogens and invasive species (Diana, 2009). ...
Article
Full-text available
Japanese seafood market has witnessed a slow but steadfast increase in the amount of certified seafood circulated on the market despite the fact that there are few incentives to apply for certification schemes such as the Marine Stewardship Council (MSC) and the Aquaculture Stewardship Council (ASC). This is because it is difficult for the producers to reap benefits from the price premium as the retailers are unwilling to charge the consumers with a higher price for the certified seafood; at the same time, there are no sourcing codes set by the retailers to ban the access of uncertified seafood. By conducting semi-structured interviews with the applicants of MSC and ASC, this study reveals the motivation of the applicants such as the desire of producers to differentiate their seafood products from similar products on the market and to establish stable distribution channels with large retailers. We argue that this type of motivation poses a unique challenge in promoting sustainable seafood in Japan, that is the certified product needs to remain a small proportion of circulated seafood products.
... Penaeus monodon, Penaeus merguiensis, and Penaeus indicus were the major species that are cultivated in the Philippines that were affected by diseases [45]. Diseases are the topmost issues and challenges in shrimp aquaculture worldwide [9,18]. According to Andrino-Felarca et al. [18,45]. ...
Article
Full-text available
Shrimp aquaculture is under pressure to increase its production to meet the growing demand for food from a growing population. In the Philippines, aquaculture has experienced the shift from milkfish to prawn, with its attractive marketable price. This intensification has led to negative and positive impacts, which have raised a range of environmental and socioeconomic problems. This paper reviews the environmental and socioeconomic challenges that the shrimp aquaculture industry faces using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)method. We examine the gaps and the changes that are required to revitalize the industry. We examine and assess the impacts of shrimp culture on the environment, e.g., shrimp farm management, marine pollution, disease outbreaks, and the social, economic, and climate change impacts. The presence of viral diseases, such as White Spot Syndrome Virus (WSSV), Monodon Baculovirus (MBV), Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV), Hepatopancreatic Parvovirus(HPV), and Yellow Head Virus (YHV), have caused approximate losses in the industry of 40,080mt in 1997, and 51,000 mt in 2014. Recommended strategies and policy changes are considered for the improvement of shrimp aquaculture, including disease management, the adoption of good aquaculture practices, proper environmental monitoring, sustainable practices at the farm level, and priorities for cooperation among the concerned government agencies and local governments, as well as the involvement of state universities and colleges, for better management practices.
... Penaeus monodon, Penaeus merguiensis, and Penaeus indicus were the major species that are cultivated in the Philippines that were affected by diseases [45]. Diseases are the topmost issues and challenges in shrimp aquaculture worldwide [9,18]. According to Andrino-Felarca et al. [18,45]. ...
Preprint
Full-text available
Aquaculture production is under pressure to increase its production to meet the growing demand for food from a growing population. In the Philippines, aquaculture has experienced the shift from milkfish to prawn with its attractive marketable price. Its intensification has led to negative and positive impacts making its collapse inevitable in the mid-1990s and raised a range of environmental and socioeconomic problems. This paper reviewed the environmental impacts, challenges, and disease outbreaks that overtook the industry using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. We examined gaps and changes required to revitalize the industry to properly take-off. It considers and gives details on the impacts of shrimp culture on the environment e.g. shrimp farm management, marine pollution, disease outbreaks, climate change impacts, and socioeconomic impacts. Moreover, the presence of viral diseases such as White Spot Syndrome Virus (WSSV), Monodon Baculovirus (MBV), Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV), Hepatopancreatic Parvovirus (HPV), and Yellow Head Virus (YHV), have caused socioeconomic impacts with approximate losses of 40,080 mt in 1997 to 51,000 mt in 2014 in the shrimp industry. Recommended strategies were considered to improve the environmental management of shrimp aquaculture, including disease management, and priorities that were highlighted for future research. This management relates to adopting good aquaculture practices on shrimp culture, proper environmental monitoring and sustainable practices at the farm level.
... Fish reared in aquaculture are in the majority free of predation due to emphasis in aquaculture on high yield (except carnivorous fish breeding programs with the presence of cannibalistic individuals). Therefore, hatchery-reared fish are naive to most predators they encounter after stocking [20][21][22]. The sudden encounter with a predator is therefore a novel experience, and it can be fatal within a very short time after fish release [23,24]. ...
Article
Full-text available
Many endangered fish species in the wild are artificially bred, and their populations are strengthened by the stocking of aquaculture-raised juveniles. Because fish from aquaculture are generally not well prepared for the challenging life in the wild, we tested whether training for selected challenges could improve fish survival after stocking. We chose conditioning on predation pressure (by learning predator image of northern pike Esox lucius using predator chemical cues and visual stimuli), increased rearing water velocity 20 cm × s−1, and direct exposure to predation. The juvenile cyprinid fish asp (Leuciscus aspius) was used as a model prey species. A total of 7949 asp were reared in four groups using a combination of high flow, predation, and control treatments (low flow, no predation; 2018, 2149, 1929, and 1856 individuals, respectively). Of these, 1800 individuals were released into three ponds with pike, and their mortality rates were monitored in relation to predation for two months after stocking using passive telemetry arrays. The remaining 6149 aquaculture-reared individuals were released directly into a large reservoir, while 1426 individuals that survived pike predation for two months were released after the pond experiment ended. Fish survival in a reservoir was monitored in 2020 and 2021 by boat electrofishing and passive telemetry. The effect of training in aquaculture was not detected in pond conditions, but the fish that survived direct predation from pike for two months in the semi-natural treatment were more likely to survive in the wild than their aquaculture-reared counterparts. In the laboratory environment, asp responded to predator chemical cues with an increase in shoal cohesion and swimming activity, which demonstrate their ability to detect chemical cues. However, exposure to more fluvial conditions did not result in increased critical swimming speed. The study suggests that conditioning tested in aquaculture may not be sufficient to prepare fish for the wild, while exposing fish to direct predation could increase fish survival.
... There has been an increasing interest in epigenetics research applied to aquaculture [19], since it has become the fastest growing food production sector in the world [20]. While some fish species such as carp have a known long history of domestication, many new aquatic species are currently at early stages of domestication [21]. ...
Article
Full-text available
Animal domestication is a process of environmental modulation and artificial selection leading to permanent phenotypic modifications. Recent studies showed that phenotypic changes occur very early in domestication, i.e., within the first generation in captivity, which raises the hypothesis that epigenetic mechanisms may play a critical role on the early onset of the domestic phenotype. In this context, we applied reduced representation bisulphite sequencing to compare methylation profiles between wild Nile tilapia females and their offspring reared under farmed conditions. Approximately 700 differentially methylated CpG sites were found, many of them associated not only with genes involved in muscle growth, immunity, autophagy and diet response but also related to epigenetic mechanisms, such as RNA methylation and histone modifications. This bottom-up approach showed that the phenotypic traits often related to domestic animals (e.g., higher growth rate and different immune status) may be regulated epigenetically and prior to artificial selection on gene sequences. Moreover, it revealed the importance of diet in this process, as reflected by differential methylation patterns in genes critical to fat metabolism. Finally, our study highlighted that the TGF-β1 signalling pathway may regulate and be regulated by several differentially methylated CpG-associated genes. This could be an important and multifunctional component in promoting adaptation of fish to a domestic environment while modulating growth and immunity-related traits.
... The opponents of spawner harvesting, in addition to arguing that these treatments are neither effective or economically justified, give specific examples of failed fish stocking campaigns, and often mention hazards to biodiversity or changes to the natural environments themselves, that can result from irresponsible or inappropriate stocking (Cambray 2003, Johnson et al. 2009, Czarkowski and Kapusta 2016. On the other hand, fish stocking promoters (Mickiewicz 2016) claim that the harvesting of spawners is a key element of fisheries management, and that one of the most important goals of these measures is to maintain or increase the size of economically valuable fish species populations to a level that makes the fisheries management economically viable (Mickiewicz and Wo³os 2011, Zakêoe and Demska-Zakêoe 2011, Trella and Wo³os 2021a and ecologically important, particularly in terms of biodiversity preservation (Diana 2009). In addition, the entities authorised to fishing are required to carry out fish stocking operations (Mickiewicz 2016), therefore, in contrast to angling organisation in e.g. ...
Article
In recent years, the issue of spawner harvesting has been frequently addressed by different groups of stakeholders involved in the exploitation of fish resources. The increasingly numerous angling circles, which use these resources recreationally, question the current rules of fish stocking management in Poland, and its legal and economic status has become the focus of scientists’ interest. The aim of the study was to present and discuss the results of a questionnaire survey addressed to managers and owners of lake fisheries entities in order to identify the determinants of fisheries management related to spawner harvesting. Questionnaires were collected from a total of 76 entities, and concerned 1921 lakes with a total area of 174,078 ha, which accounts for more than 64% of the total area of lakes used for fishing and angling purposes in Poland. The paper presents inter alia the occupational characteristics of the respondents; their positions on the effect of spawner harvesting on lake ecosystem, environmental protection, and social factors; anglers’ assessments of spawner harvesting; the actual and potential methods for regulating this harvesting; and the negative and positive effects of the introduction of a prohibition on this harvesting. The results show that the respondents under study generally do not see the need for the introduction of additional (except those already in place) regulations concerning spawner harvesting, most of them notice the adverse effects of their introduction, but they are also aware of the possible changes and their impact on management.
... Indeed, some studies are asserting that the genetic diversity in breeding farms decreased significantly and it is important to carry out studies on genetic data to maintain an effective conservation program [5]. The differences between culture and natural populations will be revealed through research on natural stocks and the conservation of biodiversity [6]. In this regard, it is clearly seen that it is very important to reveal the genetic diversity in the natural habitat before the culture of D. vulgaris, which is thought to have an economic value in Turkey. ...
Article
Full-text available
In this study, the genetic polymorphism of common two-banded seabream (Diplodus vulgaris Geoffory Saint-Hilarie, 1817), a species belonging to the Sparidae family and living in the Eastern Medi-terranean coast of Turkey, was examined using different microsatellite markers. A total of 69 D. vul-garis were obtained from the fish vendors in Mersin, Antalya and İskenderun Bay and their DNAs were isolated from the muscle tissue. The chromosomal DNAs isolated from the sample tissues were amplified with the help of Dvul33, Dvul38, and Dvul84 microsatellite markers. As a result of the phyloge-netic analysis, it was found that the fish obtained from Mersin and Antalya had similar genotype characteristics. It was also found that the fish obtained from İskenderun showed a different polymorphism due to local mobility. It is thought that this genetic differentiation will help future selection and breeding studies.
... If widely accepted, such technology could challenge traditional livestock production systems, but not necessarily reducing greenhouse gas (GHG) emissions while also increasing the demand for starch crops such as maize (Lynch and Pierrehumbert, 2019). New technologies for large-scale production of seafood on land and in ocean cages could increase seafood accessibility for consumers and possibly reduce pressure on wild fish stocks (Diana, 2009). Linking new developments in aquaculture and livestock by producing feed from algae could significantly reduce GHG emissions in livestock, the largest GHG emitter in agriculture (Roque et al., 2019). ...
Article
Full-text available
The combination of advances in knowledge, technology, changes in consumer preference and low cost of manufacturing is accelerating the next technology revolution in crop, livestock and fish production systems. This will have major implications for how, where and by whom food will be produced in the future. This next technology revolution could benefit the producer through substantial improvements in resource use and profitability, but also the environment through reduced externalities. The consumer will ultimately benefit through more nutritious, safe and affordable food diversity, which in turn will also contribute to the acceleration of the next technology. It will create new opportunities in achieving progress towards many of the Sustainable Development Goals, but it will require early recognition of trends and impact, public research and policy guidance to avoid negative trade-offs. Unfortunately, the quantitative predictability of future impacts will remain low and uncertain, while new chocks with unexpected consequences will continue to interrupt current and future outcomes. However, there is a continuing need for improving the predictability of shocks to future food systems especially for ex-ante assessment for policy and planning.
... In certain parts of the world, coastal social-ecological systems understood as complex coupled human-environment systems (Berkes et al. 1998), are undergoing a shift from one where most production comes from capture fisheries to one where aquaculture dominates production. Such shifts raise sustainability concerns related to pressure and conflict around coastal resources (Bavinck et al. 2018), water pollution (Duarte et al. 2009), biodiversity effects (Diana 2009), benefit distribution (Salayo et al. 2012), and nutritional implications (Belton and Thilsted 2014), among others. ...
Article
Full-text available
Aquaculture is the most rapidly growing food production sector globally. In certain coastal social-ecological systems, this has resulted in significant changes and sustainability challenges. In particular, coastal environments which used to support only capture fisheries are becoming sites for brackish water aquaculture production; this impacts the sustainability of aquatic food production. Sustainability challenges associated with aquaculture expansion and intensification necessitate a contextually rooted understanding of institutions and institutional changes which can be used as an informed basis for leveraging institutions to achieve desirable sustainability outcomes in the aquatic food sector. This research used a qualitative empirical case study involving in-depth interviews, participant observation, and analysis of institutional documents in the region of Central Luzon, Philippines. It applied the inter-institutional systems concept which considers multiple institutions with distinct but linked purposes and functions in the societal spheres of state, market, and civil society. The study found that aquaculture emerged as an important livelihood because of rice farmers' need to adapt to saltwater intrusion into what were formerly rice farms. It grew into an industry due to developments in the availability and accessibility of inputs such as fingerlings and feeds. This process was also driven by the high demand and high profitability of fish farming at the time. Regulatory institutions have not adequately adapted to protect the environment. Market institutions adapted but the changes mostly benefited consignacions (middlemen) and large-scale players. However, organised groups of collaborating smallholder fishers and fish farmers are helping to address the disadvantages they face. Supplementary information: The online version contains supplementary material available at 10.1007/s10113-021-01853-4.
... Despite the deployed immune mechanisms, pathogens such as Francisella noatunensis can manipulate the host cell's iron metabolism to promote its growth [19]. Pathogen evasion is a problem due to the constant interaction between the native fauna in Chile, such as Patagonian blennie (Eleginops maclovinus), with important aquaculture species: allowing the horizontal transfer of pathogens and their subsequent dissemination [20,21]. ...
Article
The brain's immune system is selective and hermetic in most species, including fish, favoring immune responses mediated by soluble immunomodulatory factors such as serotonin and the availability of nutrients against infectious processes. Francisella noatunensis coexist with fish such as Eleginops maclovinus, which raises questions about the susceptibility and immune response of the brain of E. maclovinus against Francisella. In this study, we inoculated fish with different doses of Francisella and took samples for 28 days. We detected bacteria in the brain of fish injected with a high concentration of Francisella at all time points. qPCR analysis of immune genes indicated a response mainly in the medium-dose and early expression of genes involved in iron metabolism. Finally, brain serotonin levels were higher than in uninfected fish in all conditions, suggesting possible immunomodulatory participation in an infectious process.
... Cultivated seaweed plots have been shown to rapidly attract biodiversity, including many fish species in tropical areas (Radulovich et al., 2015). The addition of artificial facilities may provide a healthy habitat and nursery zones to marine species, resulting in a positive effect on marine biodiversity (Bernard et al., 2019;Diana, 2009). Chai et al. (Chai et al., 2018) showed enhanced biodiversity associated with a Gracilaria lemaneiformis cultivation, providing further support for using this species as a practical approach to increasing the ecosystem's health. ...
Article
Full-text available
Seaweeds are rich in macronutrients, micronutrients, and bioactive components and have great potential as sustainable resources in terms of both production and consumption of a desirable food. Still, the seaweed aquaculture industry’s rapid growth points out challenges that need to be taken into consideration when assessing environmental integrity, animal, and human health. In this review, the seaweed aquaculture’s potential impact on the wildlife and human welfare and the environmental integrity has been evaluated using the One Health approach, a principle in which human, animal, and environmental health outcomes are considered as strictly connected. This is the first effort to implement the One Health concept into the seaweed cultivation assessment, and it is meant to give new perspectives for the growth of this industry.
... Aquaculture could improve the livelihoods of fishing-dependent communities by reducing risks and economic uncertainties (e.g., 3,4]), yet it is also associated with several environmental concerns including habitat alteration, water pollution and the loss of biodiversity [5,6]. Indeed, it is still unclear how aquaculture could affect to local biodiversity especially in the context of inland aquatic systems [7,8]. However, it was found to contribute to the decline of wild fish populations [6] by introducing invasive species which harm native and endemic species [9, 10 and references within]. ...
Article
Full-text available
Several coastal communities rely heavily on wild-caught fish for personal consumption and their livelihoods, thus being sensitive to the rapid global change affecting fish availability. However, in the last century, aquaculture has been increasingly adopted. To understand the uses and changes of wild-caught fish, we conducted 30 semi-structured interviews with fishers of Laguna Lake, Philippines. Fishermen, with up to 60 years’ experience, reported catching 31 fish species as a staple food. The taxa with the greatest variety of food uses were the farmed Oreochromis aureus, and the wild Channa striata and Cyprinus carpio . Fish was boiled, fried, grilled and dried, and over 20 different local dishes were reported. Fishers reported that local communities previously relied more on wild fish, while today a greater proportion of consumed fish comes from aquaculture fish species such as Oreochromis aureus and Hypophthalmichthys nobilis . Wild fish remains a crucial aspect of local gastronomic diversity, underpinning the biodiversity of the Laguna Lake, while also representing an important element for food sovereignty. The study stresses the need to sustain local ecological knowledge to ensure the ecological, social and economic sustainability of the communities.
... Although we applaud the significant progress in the artificial propagation of C. nasus [68], we must point to the loss of genetic diversity that a massive reduction of the biomass as sea implies [69][70][71][72]. Since early 2020, much of the Yangtze River, including parts of the estuary, is officially declared protected by a ten-year fishing ban. ...
Article
Full-text available
An assessment of the stock status and historical changes in abundance of Coilia mystus and C. nasus in the Yangtze River Estuary, China, was carried out based on field surveys conducted in 2019–2020 and published length-frequency (L/F) data from earlier periods. These two species’ current and past relative biomasses (B/BMSY) were estimated using a length-based Bayesian biomass estimation method (LBB). The LLB method also estimated their asymptotic lengths (Linf), current and optimum mean lengths at first capture (Lc; Lopt_c), and their ratios of natural and fishing mortality to growth (M/K; F/K). In response to increasing fishing pressure, both species’ maximum lengths declined, along with their B/BMSY ratio, which declined for C. mystus from 1.7 in 1982 to 0.47 in 2020 and for C. nasus from 1.7 in 2006 (or earlier) to 0.17 in 2020. These assessments show that both of the two Coilia species are overfished, with C. nasus impacted more severely than C. mystus. The prospect for the recovery of these two species is briefly discussed. This contribution will help toward the management of the population of these two Coilia species and provides a basis for evaluating the effect of the 10-year fishing ban in the Yangtze River.
... Furthermore, considering the increasingly importance of the species for aquaculture exploration, and the fact that A. regius aquaculture escapees have been addressed for the western Mediterranean e.g., [50], further studies should focus on unraveling its impact in the wild populations, namely, in what concerns its genetic structure, since escapees could be related to one of the highest impacts of aquaculture on biodiversity, genetic alterations of wild stocks [51]. ...
Article
Full-text available
The meagre Argyrosomus regius, one of the largest sciaenidae in the world, is a valuable resource for fisheries and aquaculture. Despite its socioeconomic relevance, knowledge about population dynamics and wild stocks is still scarce, and conservation risks are associated with overexploitation. Two genetic distinct groups, one in the North Atlantic Ocean and one in the eastern Mediterranean Sea, were identified by previous studies. However, little is known about the genetic structure of the Atlantic group, where four important spawning areas have been identified. To assess if each spawning area is an independent breeding unit, the genetic diversity, populational structure, and demographic history of A. regius along the North–East and Eastern Central Atlantic coast were analyzed, using 15 microsatellite loci. Results corroborate the hypothesis tested, suggesting four genetic groups: a first group encompassing individuals from the Gironde spawning area, a second group encompassing individuals from the Tagus spawning area, a third group corresponding to individuals captured in the Algarve region, and a forth group gathering individuals from Morocco and Mauritania. This study reveals the need for specific fisheries management plans considering genetic structure information, and highlights the need for international cooperation.
... Global production from aquaculture and mariculture accounts for 50% of the world's fish supply (FAO, 2010;Cao et al., 2013). In recent decades, these industries have become the most rapidly increasing food production sector (Bostock et al., 2010) and still has great potential to grow at a significant rate (Diana, 2009). However, with the expansion of aquaculture and mariculture, it has been suggested that this will lead to more environmental problems, such as eutrophication, water pollution, threats to biodiversity, land use changes (LUC), and increased greenhouse gas (GHG) emissions (Mazzola et al., 2000;Read and Fernandes, 2003;Ray et al., 2019). ...
Article
Full-text available
Aquaculture and mariculture are becoming an increasingly important source of food supply food in many countries and regions. However, with the expansion of aquaculture and mariculture comes increasing emissions of greenhouse gases (GHG) which contribute to global warming and climate change. China leads the world in aquaculture and mariculture production, but there are no studies that systematically assess China's overall carbon footprint from these industries. This study quantified GHG emissions from aquaculture and mariculture by four source phases (feed, energy use, nitrous oxide and fertilizers), and then analyzed the carbon footprint of each of these phases for GHG production of nine major species groups over the past ten years to show the spatial distribution of GHG emissions from aquaculture and mariculture in China. Our results showed that the production of feed materials contributed most to the GHG emissions and found that crop energy use, crop land use changes (LUC), fertilizer production, crop nitrous oxide production and rice methane production were the main sources of feed emissions. The total GHG emissions of the nine species groups were 112 Mt (10⁹ kg) CO2e, the nine species accounting for approximately 86% of aquaculture and mariculture production. GHG emissions of cyprinids had the highest contribution at 47%. Spatial analysis based on our study showed Guangdong, Hubei, Jiangsu and Shandong had the highest GHG emissions of all the provinces in this study, and they accounted for approximately 46% of all emissions. The regional Gross Domestic Product (GDP) was significantly positively correlated with GHG emissions in every province, with a correlation coefficient higher than 0.6. Our results showed for the first time the relationship between the relative production by species composition and spatial distribution of GHG emissions from aquaculture and mariculture in China. Our findings provide the scientific basis for reduction of GHG emissions within a broader context of expanding aquaculture in the future.
... 11,[17][18][19] Globally, the most feared situation occurs when a non-native species expands its range and becomes an invader, resulting in negative effects on receiving ecosystems. 3,20 Aquaculture systems, especially floating net pens or rafts, are exposed to accidental loss or forced release of individuals. Escapes occur due to careless handling from human operators, structural failures of equipment during extreme environmental events (e.g., earthquakes, tides and waves, storms, flooding, tsunamis), third-party intervention (e.g., vandalism or theft), or the action of native predators, and even unknown causes. ...
Article
Here, we review extensive information to estimate environmental risks from escaped non‐native salmonids based on the assessments of hazard, sensitivity and exposure of discrete water bodies in Chile. In 2020, the country harvested about 1 million tons salmonids from net pens located along 1500 km of highly biodiverse coastline. We base our analysis on existing scientific information and authors' expert opinions including an assessment of knowledge gaps and uncertainties. Risks of environmental impacts differed by salmon species, being lowest for Atlantic salmon due to its estimated lower survival, lower ability to feed after escaping and lower reproductive capacity in the wild compared to coho salmon and rainbow trout. Overall risks due to escapes of any of the species were highest in areas of both high farming intensity and low capacity of mitigating escapes (by wild predators and fishers) such as Aysén District. At same time, risk was higher in the most farmed areas that also presented suitable habitats to support reproduction and juvenile salmonid rearing. However, the risk estimation certainty differed among species being lowest for Atlantic salmon due to insufficient monitoring of their fate in the wild. Monitoring the fate and impacts of escaped salmonids, specially in higher risk areas is recommended to improve risk projections and to prevent and mitigate further impacts. Since Atlantic and coho salmon are not yet successful invaders in Chile, research attention is urgently needed to assess the environmental consequences of escapes of these species. The present approach can be applied to any aquaculture system given the availability of information on farmed species and receiving ecosystems.
... In addition, fishing quantity in Benin has been declining as a result of the environmental degradation of major water bodies, increasing fishing pressure and climatic change (DSID, 2019). Aquaculture will therefore play an important role in fish production as natural fish stocks continue to decline (Diana, 2009). Although the fish farming sector provides food and economic sustenance to a part of the population, it has not been exempted from problems and criticisms (Lazard et al., 2010). ...
Article
Full-text available
Fish farming is promoted in the Republic of Benin to meet the demands of fish consumption and increase exports to neighbouring countries. Targeting fish farm policy interventions to increase the efficiency of heterogeneous fish farming systems is a challenge. Farm type delineation allows for simplifying the diversity in fish farming systems. Multivariate statistical techniques combined with the Calinski and Harabasz pseudo F statistic and bootstrapping were applied to determine the realistic number of fish farm types. Four fish farm types were identified and characterised based on farm intensity, species diversification, and the management capacity of operators. Furthermore, profits and both labour and capital productivity increased continuously from the extensive fish farms to the semi‐intensive farms. They also vary widely within farm types across the country. These farm types may be supported by appropriate fish farming promotion policy interventions. Most importantly, training programs must be tailored to each farm type to strengthen the technical and managerial capacity of the fish farmers. Farm type delineation allows for simplifying the diversity in fish farming systems. Multivariate statistical techniques combined with the Calinski and Harabasz pseudo F statistic and bootstrapping were applied to determine the realistic number of fish farm types. Four fish farm types were identified and characterized based on farm intensity, species diversification, and the management capacity of operators.
... Due to its reliance on importing foreign seafood, plus pressure on wild fisheries (National Oceanic and Atmospheric Administration [NOAA], 2016;Hixon, 2014), the United States has increasingly proposed expanding domestic aquaculture production (White House, 2020). Yet, certain production types, such as raising salmon in ocean net pens, have historically imposed considerable environmental impacts (Diana, 2009) and, despite increasingly sustainable production processes (Naylor et al., 2021), still often meet with public skepticism or opposition (Schlag, 2010). Local engagement on siting aquaculture facilities may be greeted with delight (e.g., more jobs), despair (e.g., competition with wild harvesters), or a combination (D'Anna & Murray, 2015;Hanes, 2018). ...
Article
Surveys in three U.S. localities (n = 523) with proposed or existing land‐based aquaculture facilities probed trust's relationship with perceived net benefits and public intentions to cooperate with siting of this novel technology. The trust, confidence, and cooperation (TCC) model posits that shared values shape willingness to be vulnerable to others (trust), while past performance shapes certainty that others will behave as expected (confidence). Trust affects confidence given moral outweighs performance information, possibly varying by familiarity. Other research suggests that trust shapes benefit and risk perceptions, which drive cooperation (defined here by potentially observable behavior: voting on siting, trying to influence government decisions directly or through citizen groups, and buying or eating facility fish). Confirmatory factor analyses suggested that a two‐factor model fit the trust/confidence measures better than a one‐factor model or a two‐factor model without inter‐factor correlation, indicating (despite a strong association of trust and confidence) that they are empirically distinct. Path analyses suggested that trust had stronger direct effects on cooperation than did confidence, reflecting the TCC notion that moral information underlying trust judgments is more influential, and stronger indirect effects through benefit‐risk judgments. Model fit was better than if the benefit‐risk mediator was omitted. Trust in government had a small direct effect on cooperation and confidence, but a large effect on trust in the corporation, and model fit was much worse if any of these paths was omitted. Low familiarity with the project lowered both model fit and trust–confidence association. We discuss implications for risk analysis theory and practice.
... Aquaculture is probably one of the fastest-growing food production industries in the last decade, and since 2014 has overtaken wild-catch production as a source of seafood (FAO, 2018). Aquaculture's rapid growth is a consequence of the big development of intensive aquaculture production, which has raised questions and criticism about its environmental impacts (Diana, 2009) and the potential adverse economic or social effects (Brugère et al., 2019). All this has happened in a global context where consumers are more aware of environmental issues and demand safer products (Bacher, 2015). ...
Article
Full-text available
Many investigations have looked to understand consumers' perceptions of aquaculture and its products, with Likert scales being the most popular instrument employed. In some of them, negatively and positively worded survey items are mixed looking to reduce potential acquiescence bias. Nevertheless, several studies found that this solution could be problematic because reverse recoded negatively worded statements might not exactly measure the same as their positively worded counterparts. This study aims to examine the impact of positive and negative wording on surveys that analyze the consumers' perceptions of aquaculture and its products. The results revealed that if the goal is to understand how well consumers perceive aquaculture and its products, using negative statements on Likert scale instruments is not appropriate because it increases respondents' negative perception, and the information appears to be less reliable and with more variability than that obtained with positively worded statements. In addition, our study reveals interesting insights on how to improve consumers' perceptions of aquaculture and its products for the segment of the population formed by young adults and highly educated residents.
... Actualmente, no hay un sector de producción de alimentos completamente sostenible desde un punto de vista energético y de biodiversidad, la mayoría requieren energía y agua, pero también generan residuos (Troell et al. 2017;Diana 2009). No obstante, existen métodos de cultivo más sostenibles que otros. ...
Article
Full-text available
Traditional aquaculture faces serious environmental problems, particularly due to the use of large volumes of water, with the consequent discharge of effluents rich in inorganic nutrients and organic particles. A clear example of this is that only 20 to 30% of the nitrogen present in the protein of the supplied food is used by the fish. The remaining 70 to 80% is disposed of in the water body as a result of excretion and unconsumed food, favoring the eutrophication of receiving waters and their environment. Therefore, the development of innovative, responsible, sustainable, and profitable technologies and production practices is required. One of the alternatives that is generating interest due to its environmental, economic, and social implications is the production in integrated multitrophic aquaculture systems (IMTA). This concept is based on the integration of different trophic levels in the same system, which results in a conversion of the culture residues of some species into food or fertilization for other species. Applicated, the IMTA systems can improve the sustainability of aquaculture by reducing the impact of effluents, generating greater economic profitability due to the simultaneous production of two or more end products and minimal use of fertilizers. The objective of this review is to present fundamentals basic aspects of IMTA systems, as an alternative to fish farming production systems.
... Introduced species often occur due to accidental escaping from nearby ponds and deliberate introduction by fishermen (Humpl & Pivnicka 2006). It is known that the most damaging effect of aquaculture on biodiversity loss is the escapement of introduced cultivated fish species and their potential to be invasive (Diana 2009). Due to predation, one detrimental effect is the depletion of the stock of the valued smaller commercial and non-commercial fish species. ...
Article
Full-text available
This study aimed to evaluate the diversity and distribution of freshwater fishes in Bayog Watershed, Bayog, Zamboanga del Sur, Philippines. A total of 1408 fish individuals were collected, comprising 11 families, 13 genera, and 19 species. Out of the 19 species, 11 were identified as endemic and native, while eight were introduced species. The presence of Pterygoplichthys disjunctivus is the most concerning since it would be a possible pest in this area. The two most abundant species comprised 51% of the overall count: Oreochromis niloticus (25.99%) and Barbodes binotatus (25.5%). Shannon-Weiner's diversity indices calculated for the six sampling sites varied from 1.67 to 2.05 (H'=2.04), which is relatively good. However, the abundance of many introduced species may disrupt the population structures of the native/endemic freshwater species in the different sites. The information generated in this study may serve as one of the bases for different conservation strategies for the fish of the area.
... Currently, the fish sector in food systems is associated with ecosystem damage from overfishing and unsustainable aquaculture practices that result in damage to life under water (Diana, 2009;FAO et al., 2020). The indicator monitoring the SDG target 14.4 shows that fish stocks within biologically sustainable level have deteriorated from 90% of stocks in 1974 to 66% in 2017 and more than 30% have been overfished (FAO, 2020). ...
Article
Full-text available
Food production for human consumption is a leading cause of environmental damage in the world and yet over two billion people suffer from malnutrition. Several studies have presented evidence that changes in dietary patterns across the world can lead to win-win outcomes for environmental and social sustainability and can complement ongoing technological and policy efforts to improve the efficiency of agricultural production. However, the existing evidence have been compiled in “silos” by a large range of researchers across several disciplines using different indicators. The aim of this quantitative review is to bring together the existing knowledge on heterogeneity of current dietary patterns across the world and how a transition toward healthy diets in different countries can aid in progress toward multiple global Sustainable Development Goals (SDGs). We first summarize the nutritional quality, economic cost, and environmental footprint of current diets of over 150 countries using multiple indicators. Next, we review which shifts in dietary patterns across different world regions can help toward achievement of SDG2 (Zero hunger), SDG3 (Good health and wellbeing), SDG 6 (Clean water and sanitation), SDG13 (Climate action), SDG14 (Life below water), and SDG15 (Life on land). Finally, we briefly discuss how to enable the shift toward sustainable dietary patterns and identify the research and data gaps that need to be filled through future efforts. Our analysis reveals that dietary change is necessary in all countries as each one has unique priorities and action items. For regions such as Sub-Saharan Africa and South Asia, increased intake of nutrient dense foods is needed to address deficiency of essential nutrients like folate, potassium, and vitamin A. For North America and Europe, shifting toward more plant-based diets would be healthier and simultaneously reduce the per capita environmental footprints. The results can be useful for policymakers in designing country-specific strategies for adoption of sustainable dietary behaviors and for food industry to ensure the supply of sustainable food items customized with regions' need.
... Positive impacts of floodplain aquaculture on ecology and fish biodiversity were recorded by (Hossain et al., 2014). A positive impact of aquaculture on aquatic production and both a positive and negative impact on aquatic biodiversity were observed (Diana, 2009). All leaseholders claimed to be performing admirably in terms of fish production and biodiversity richness, both physically and ecologically. ...
Article
Full-text available
This research was conducted to explore the status of fish species diversity and production in the Kawadighi Haor of northeastern Bangladesh. Data were collected biweekly through direct catch assessment surveys, focus group discussions, and personal interviews using a questionnaire. A total of 87 fish and prawn species belonging 14 orders and 30 families were identified in the Haor, where 18% species were abundantly available, 20% were commonly available, 42% were moderately available and 20% were rarely available. Among the recorded species, Cypriniformes, having 34 species, had the most species, followed by Siluriformes (20), Anabantiformes (11), Ovalentaria (4), Synbranchiformes (4), Clupeiformes (3), Decapoda (3), Osteoglossiformes (2), Anguilliformes (1), Beloniformes (1), Cyprinodontiformes (1), Gobiiformes (1), Mugiliformes (1), and Tetraodontiformes (1). The values of Shannon-Weaver diversity (H), Margalef’s richness (d), and Pielou’s evenness (J) indices were 2.98, 7.72 and 0.67 in Hawagulaia, 2.97, 7.52 and 0.67 in Patasingra and 2.61, 7.30 and 0.59 in Salkatua beel, respectively. The haor's average yearly fish production was 704.09 kg/ha. Small indigenous species (SIS) of fish dominated the haor's total production, accounting for 51.8 to 70.57 percent of the total contribution. The highest portion of fish produced in the non-stocked beel was SIS of fish but per hectare SIS of fish production of non-stocked beel was lower than the fingerling stocked beels. Aquaculture might have a good effect on fish production and biodiversity. The findings showed that Kawadighi Haor is a very productive and biodiversity-rich inland open waterbody that may function as a mother fishery. For the protection of current fisheries resources, multiple approaches including public awareness campaigns might be beneficial.
... The intensification of aquaculture has a dramatic effect on seabed fauna and their abundance (Diana, 2009;Tsutsumi et al., 1991). In turn, coastal pollution (agriculture, hydrocarbon, heavy metals) and marine pollution affect the success of aquaculture (Eng et al., 1989). ...
Chapter
Full-text available
Over fifty years of global conservation has failed to bend the curve of biodiversity loss, so we need to transform the ways we govern biodiversity. The UN Convention on Biological Diversity aims to develop and implement a transformative framework for the coming decades. However, the question of what transformative biodiversity governance entails and how it can be implemented is complex. This book argues that transformative biodiversity governance means prioritizing ecocentric, compassionate and just sustainable development. This involves implementing five governance approaches - integrative, inclusive, adaptive, transdisciplinary and anticipatory governance - in conjunction and focused on the underlying causes of biodiversity loss and unsustainability. Transforming Biodiversity Governance is an invaluable source for academics, policy makers and practitioners working in biodiversity and sustainability governance. This is one of a series of publications associated with the Earth System Governance Project. For more publications, see www.cambridge.org/earth-system-governance. This title is also available as Open Access on Cambridge Core.
... Refer to the UNODC Fisheries Crime, at https://bit.ly/3GYAGUv. The intensification of aquaculture has a dramatic effect on seabed fauna and their abundance (Diana, 2009;Tsutsumi et al., 1991). In turn, coastal pollution (agriculture, hydrocarbon, heavy metals) and marine pollution affect the success of aquaculture (Eng et al., 1989). ...
Chapter
Freshwater fish are one of the most diverse groups of vertebrates, but are also amongst the most threatened. With contributions from leaders in the field, this is the first assessment of the global state of freshwater fish diversity, synthesising the opportunities, challenges and barriers facing the conservation of freshwater fish biodiversity. The book includes the first global assessment of the number, type and distribution of threatened freshwater fish species, discussing the features of freshwater fish biology and ecology that render so many species vulnerable to extinction. Introductory chapters on why freshwater fish are so sensitive to environmental change and disturbance lead into chapters providing detailed reviews of the key threatening processes and potential solutions. A concluding chapter summarises the key issues and looks to the future for opportunities and challenges for the conservation and management of freshwater fish.
Article
Full-text available
The giant freshwater prawn (GFP), Macrobrachium rosenbergii has emerged as a significant crustacean in global aquaculture. A cradle-to-farm Life Cycle Assessment (LCA) was used to assess the potential environmental impacts of GFP in Malaysia. The four main iterative farming phases involved were pond preparation, stocking, farming, and harvesting. The impact categories chosen were global warming, terrestrial ecotoxicity, terrestrial acidification, freshwater eutrophication, human non-carcinogenic toxicity, human carcinogenic activity, and water consumption. The software SimaPro 9.3.0.3 was used for impact analysis, with background data from the database Ecoinvent 3.0. and ReCiPe 2016 Midpoint (H) V1.06/World (2010). Among other environmental impact categories, stocking and harvesting phases contributed to human carcinogenic toxicity impact values of 33.33%, followed by farming (33.31%). Another impact category, freshwater ecotoxicity also produces the same pattern with the stocking and harvesting process, still generating the highest impact value of 33.34%, followed by farming (33.30%). Apart from the identified capital items that require consideration for future waste management in aquaculture, this LCA study found that M. rosenbergii farming generates a low impact to the environment, however, could inspire further research on other perspectives of sustainability.
Chapter
Freshwater fish are one of the most diverse groups of vertebrates, but are also amongst the most threatened. With contributions from leaders in the field, this is the first assessment of the global state of freshwater fish diversity, synthesising the opportunities, challenges and barriers facing the conservation of freshwater fish biodiversity. The book includes the first global assessment of the number, type and distribution of threatened freshwater fish species, discussing the features of freshwater fish biology and ecology that render so many species vulnerable to extinction. Introductory chapters on why freshwater fish are so sensitive to environmental change and disturbance lead into chapters providing detailed reviews of the key threatening processes and potential solutions. A concluding chapter summarises the key issues and looks to the future for opportunities and challenges for the conservation and management of freshwater fish.
Chapter
Freshwater fish are one of the most diverse groups of vertebrates, but are also amongst the most threatened. With contributions from leaders in the field, this is the first assessment of the global state of freshwater fish diversity, synthesising the opportunities, challenges and barriers facing the conservation of freshwater fish biodiversity. The book includes the first global assessment of the number, type and distribution of threatened freshwater fish species, discussing the features of freshwater fish biology and ecology that render so many species vulnerable to extinction. Introductory chapters on why freshwater fish are so sensitive to environmental change and disturbance lead into chapters providing detailed reviews of the key threatening processes and potential solutions. A concluding chapter summarises the key issues and looks to the future for opportunities and challenges for the conservation and management of freshwater fish.
Article
Improving the energy efficiency of fish culture has always been a concern for warm‐water fish farming units. In this respect, the present study explored energy consumption flow and energy indices of warm‐water fish production in Guilan province, northern Iran. The impact of the energy equivalent of the system inputs on the energy equivalent of fish yield was modeled by the Cobb‐Douglas function. The results revealed that total energy input, energy ratio, energy productivity, and energy intensity were 3710.4 MJ per 100 m2, 0.042, 0.009 kg MJ‐1, and 109.77 MJ kg‐1, respectively. Feed, electricity, and fossil fuel were the most energy‐intensive inputs accounting for 70.09%, 11.95%, and 11.70% of total energy use, respectively; representing the dominant role of feed in the energy input of warm‐water fish farming. Renewable and non‐renewable energy resources accounted for 6.97% and 93.03% of the total energy input of warm‐water fish culture system, respectively; requiring more care to cut the share of non‐renewable energy inputs. The Pareto chart determined that fingerling, labor, and electricity had the highest effects on the warm‐water fish yield. Therefore, more attention should be paid to the appropriate use of these inputs in warm‐water fish culture in the study region. This article is protected by copyright. All rights reserved.
Chapter
Freshwater fish are one of the most diverse groups of vertebrates, but are also amongst the most threatened. With contributions from leaders in the field, this is the first assessment of the global state of freshwater fish diversity, synthesising the opportunities, challenges and barriers facing the conservation of freshwater fish biodiversity. The book includes the first global assessment of the number, type and distribution of threatened freshwater fish species, discussing the features of freshwater fish biology and ecology that render so many species vulnerable to extinction. Introductory chapters on why freshwater fish are so sensitive to environmental change and disturbance lead into chapters providing detailed reviews of the key threatening processes and potential solutions. A concluding chapter summarises the key issues and looks to the future for opportunities and challenges for the conservation and management of freshwater fish.
Chapter
Freshwater fish are one of the most diverse groups of vertebrates, but are also amongst the most threatened. With contributions from leaders in the field, this is the first assessment of the global state of freshwater fish diversity, synthesising the opportunities, challenges and barriers facing the conservation of freshwater fish biodiversity. The book includes the first global assessment of the number, type and distribution of threatened freshwater fish species, discussing the features of freshwater fish biology and ecology that render so many species vulnerable to extinction. Introductory chapters on why freshwater fish are so sensitive to environmental change and disturbance lead into chapters providing detailed reviews of the key threatening processes and potential solutions. A concluding chapter summarises the key issues and looks to the future for opportunities and challenges for the conservation and management of freshwater fish.
Chapter
Freshwater fish are one of the most diverse groups of vertebrates, but are also amongst the most threatened. With contributions from leaders in the field, this is the first assessment of the global state of freshwater fish diversity, synthesising the opportunities, challenges and barriers facing the conservation of freshwater fish biodiversity. The book includes the first global assessment of the number, type and distribution of threatened freshwater fish species, discussing the features of freshwater fish biology and ecology that render so many species vulnerable to extinction. Introductory chapters on why freshwater fish are so sensitive to environmental change and disturbance lead into chapters providing detailed reviews of the key threatening processes and potential solutions. A concluding chapter summarises the key issues and looks to the future for opportunities and challenges for the conservation and management of freshwater fish.
Chapter
Freshwater fish are one of the most diverse groups of vertebrates, but are also amongst the most threatened. With contributions from leaders in the field, this is the first assessment of the global state of freshwater fish diversity, synthesising the opportunities, challenges and barriers facing the conservation of freshwater fish biodiversity. The book includes the first global assessment of the number, type and distribution of threatened freshwater fish species, discussing the features of freshwater fish biology and ecology that render so many species vulnerable to extinction. Introductory chapters on why freshwater fish are so sensitive to environmental change and disturbance lead into chapters providing detailed reviews of the key threatening processes and potential solutions. A concluding chapter summarises the key issues and looks to the future for opportunities and challenges for the conservation and management of freshwater fish.
Chapter
Freshwater fish are one of the most diverse groups of vertebrates, but are also amongst the most threatened. With contributions from leaders in the field, this is the first assessment of the global state of freshwater fish diversity, synthesising the opportunities, challenges and barriers facing the conservation of freshwater fish biodiversity. The book includes the first global assessment of the number, type and distribution of threatened freshwater fish species, discussing the features of freshwater fish biology and ecology that render so many species vulnerable to extinction. Introductory chapters on why freshwater fish are so sensitive to environmental change and disturbance lead into chapters providing detailed reviews of the key threatening processes and potential solutions. A concluding chapter summarises the key issues and looks to the future for opportunities and challenges for the conservation and management of freshwater fish.
Article
The plummeting productivity of marine resources complemented by a growing demand for fish and its products makes the intensification of aquaculture systems inevitable. Such intensification breeds the predicament of nutrient loading which eventually hampers the smooth functioning of an aquatic ecosystem. Ecological engineering, working in tandem with aquaculture has evolved a system under the backdrop of Integrated multi-trophic aquaculture (IMTA) which facilitates such intensification. IMTA involves simulating a co-culture system that mimics a natural aquatic ecosystem, entailing multiple tropic levels arranged in a way to harness the potential of by-products and thereby minimize waste production. IMTA offers a sustainable approach to aquaculture development with a two-component stock configuration of fed aquatic species (fish or shrimp) and extractive species (seaweeds, molluscs, echinoderms etc). The theme of the setup is to feed the fed component and utilize their waste for the culture of the extractive species. Since its inception, the IMTA has evolved in every aspect ranging from diversification of its components to its expansion to open waters, providing avenues that support its emergence as the aquaculture of the future. The following paper reviews the evolution of IMTA in the context of its need, components and design, besides providing ways to valorize the system via diversification and optimization.
Article
Unplanned aquaculture led to the destruction of important ecosystems worldwide. A multi-criteria land suitability model (MLSM) was developed to locate the suitable regions for aquaculture using satellite images, AHP and Monte Carlo simulation, spatial analysis, resource characteristics, and regulations. Twenty-one variables within four subgroups (land use, water quality, soil characteristics, and infrastructure support) have been integrated for the site suitability. Land availability was the major limiting factor. The area available for aquaculture was 4310 ha in Ramanathapuram District, which consists of 33.3% of most appropriate, 23.1% of appropriate, and 43.6% of moderately appropriate regions. The carrying capacity of rivers indicated that all rivers had sufficient nutrient assimilation capacity, except the Kottagudi River, where the aquaculture planning is to be within the carrying capacity of the river. The sensitivity analysis confirmed that integrated MLSM and carrying capacity approach could be adopted to identify suitable zones to develop aquaculture and save productive ecosystems.
Article
This review summarizes (1) the U.S. status quo for aquatic food animal production and marketing; (2) major food safety and quality issues/concerns for aquatic food animals in the United States, including fish misbranding, finfish/shellfish allergies, pathogens, toxins and harmful residues, microplastics, and genetically engineered salmon; and (3) various U.S. regulations, guidances, and detection methods for the surveillance of fishery products. Overall, fish misbranding is the biggest challenge in the United States due to the relatively low inspection rate. In addition, due to the regulatory differences among countries, illegal animal drugs and/or pesticide residues might also be identified in imported aquatic food animals. Future regulatory and research directions could focus on further strengthening international cooperation, enhancing aquatic food animal inspection, and developing reliable, sensitive, and highly efficient detection methods.
Article
Full-text available
Human activities, particularly habitat destruction and species introductions, are resulting in increased homogenization of once unique biogeographic regions. In the southeastern United States, extensive endemism occurs among highland fish species that have specialized ecologies, are adapted to cool, clear, nutrient-poor conditions, and are sediment-intolerant. Highland streams flow into lower elevation systems, which are often inhabited by more widespread, generalist fish species adapted to warmer, more turbid, fine-sediment-rich, and nutrient-rich conditions. Common land use practices, such as deforestation, degrade stream habitats and reduce habitat diversity, which is often correlated with taxonomic and ecological diversity. Habitat homogenization can thus cause assemblage homogenization via loss of native species and addition of nonindigenous species. However, midpoints in the homogenization process may be characterized by constant or even increased species diversity because generalist, sediment-tolerant, “native” species invade from downstream areas. Perusal of a species list for a river system would not reveal such invasions because lists seldom discriminate between upstream and downstream assemblages in a drainage. Traditional metrics often used in biological assessment, such as species richness (α diversity) and evenness, should not include invasive species, whether native or exotic. Greater attention should be paid to the actual species present and their ecological requirements, and to changes in overlap in species occurrence among regions. Aquatic ecosystem integrity can degrade despite apparent increases in species diversity.
Article
Full-text available
Global production of farmed fish and shellfish has more than doubled in the past 15 years. Many people believe that such growth relieves pressure on ocean fisheries, but the opposite is true for some types of aquaculture. Farming carnivorous species requires large inputs of wild fish for feed. Some aquaculture systems also reduce wild fish supplies through habitat modification, wild seedstock collection and other ecological impacts. On balance, global aquaculture production still adds to world fish supplies; however, if the growing aquaculture industry is to sustain its contribution to world fish supplies, it must reduce wild fish inputs in feed and adopt more ecologically sound management practices.
Article
Full-text available
The identification and risk assessment of potential biological invaders would provide valuable criteria for the allocation of resources toward the detection and control of invasion threats. Yet, freshwater biologists have made few attempts at predicting potential invaders, apparently because such efforts are perceived to be costly and futile. We describe some simple, low-cost empirical approaches that would facilitate prediction and demonstrate their use in identifying high-risk species from an important donor region: the Ponto-Caspian (Black, Caspian, and Azov seas) basin. This region is the source of several freshwater organisms already invading North America, including the zebra mussel (Dreissena polymorpha), quagga mussel (Dreissena bugensis), ruffe (Gymnocephalus cernuus), and round goby (Neogobius melanostomus). Based on a thorough literature review, we identify 17 additional Ponto-Caspian animals that have recent invasion histories and are likely to be transported overseas in ship ballast water; moreover, their broad salinity tolerance could allow them to survive an incomplete ballast-water exchange. These results suggest that, unless current vectors are more effectively controlled, the Great Lakes - St. Lawrence River system and other North American inland waterways will continue to receive and be impacted by invasive Eurasian species.
Article
Full-text available
From 1985 to 1988, the Saguling and Cirata hydropower reservoirs in the highlands of West Java, Indonesia, displaced more than 40,000 families. As part of a comprehensive resettlement plan, an attempt to resettle 3,000 families in water-based f loating fish cage aquaculture and land-based aquaculture sup port was initiated. Although the reservoir cage aquaculture developments were successful from a fish-production viewpoint, since 1944 cage aquaculture has not been socially or environmentally sustainable. Fish cage aquaculture in reservoirs can be an important new means ofpopulation resettlement from hy dropower dam construction and protein production in tropical developing countries only with adequate government planning for fisheries; adequate fi nancial compensation for lost assets; rigid enforcement of institutional regula tions guaranteeing the long-term benefits of the new lakes for the exclusive use of the displaced people; enforcement of regulations on cage numbers to prevent environmental degradation; and adequate government subsidies for aquacul ture job creation, training, long-term extension support, and active monitoring.
Article
Full-text available
The farming of salmon and other marine finfish in open net pens continues to increase along the world's coastlines as the aquaculture industry expands to meet human demand. Farm fish are known to escape from pens in all salmon aquaculture areas. Their escape into the wild can result in interbreeding and competition with wild salmon and can facilitate the spread of pathogens, thereby placing more pressure on already dwindling wild populations. Here we assess the ecological, genetic, and socioeconomic impacts of farm salmon escapes, using a risk-assessment framework. We show that risks of damage to wild salmon populations, ecosystems, and society are large when salmon are farmed in their native range, when large numbers of salmon are farmed relative to the size of wild populations, and when exotic pathogens are introduced. We then evaluate the policy and management options for reducing risks and discuss the implications for farming other types of marine finfish.
Article
Full-text available
On 16 November 1963, the U. S. Fish and Wildlife Service Fish Farming Experimental Station at Stuttgart, Arkansas, became the first institution to import grass carp (Ctenopharyngodon idella) into the United States. This introduction was the result of at least seven years of effort to find an effective biological control for problematic aquatic weeds. The introduction was in keeping with a strong environmental and political mandate of that day to replace the broad use of chemicals with biological controls. For about 10 years, federal and state agencies and university systems strongly promoted introductions, spawning, and nationwide stocking of the grass carp. In 1966, the USFWS laboratory at Stuttgart, Arkansas, was apparently responsible for the first accidental release of grass carp to the environment. By 1972, grass carp were stocked in open water systems, documented in 16 states, and established in the Mississippi River system. All this occurred before the first private-sector commercial producers received and spawned the fish in 1972 and 1973, respectively. From 1972 to 1985, public agencies were actively involved in research to produce non-reproductive grass carp for stocking purposes and in 1983, in conjunction with a private producer, these efforts led to the development of triploid grass carp. In 1985, an official U.S. Fish and Wildlife Service biological opinion was rendered that grass carp triploids were an environmentally safe, weed-controlling fish. In the same year, the U.S. Fish and Wildlife Service established a triploid grass carp ploidy inspection program that opened the way to ship certified triploid grass carp around the country. From 1985 to 2005, more than 7 million triploid grass carp were shipped throughout the United States. With grass carp now officially recorded from 45 states it is important to be aware of (or remember) the facts surrounding its introduction, early spread, present usage, and need. Understanding these will in turn will allow for more rational decisions to be made concerning the future of these fish.
Article
Full-text available
Contrary to several recent studies, a review (Brooks, 2005) of sea lice (Lepeophtheirus salmonis) interactions between wild and farm salmon in the Broughton Archipelago, British Columbia, Canada, concluded that there is little potential for sea lice transmission from farm to wild salmon. In this rebuttal, we show that this conclusion was based on a flawed interpretation of how salinity affects louse development, a misunderstanding of how the timing of salinity changes corresponds to the timing of the juvenile salmon migration, models of larval dispersion that overestimate the transport of louse larvae, and a selective and misleading assessment of the literature. We analyze and extend the current models of larval dispersion and demonstrate the (perhaps counter-intuitive) result that sustained high abundances of infectious larvae should be expected near lice-infested salmon farms. We also highlight important studies overlooked in Brooks (2005) and clarify some misinterpretations. Counter to the conclusions in Brooks (2005), the modeling and empirical work to date on sea lice interactions between wild and farm salmon are consistent and point to a strong association between salmon farming and recurrent infestations of wild juvenile salmon in the Broughton Archipelago.
Article
Full-text available
Although many fisheries stocks have declined precipitously throughout the world, fish farming--and especially shrimp and salmon farming--has boomed. The increasingly large scale of these enterprises is now having unforeseen ecological consequences on ocean resources through habitat destruction, effluent discharge, exotic species introductions, and heightened fish catch for feed use. Ending unsustainable production practices will require reorienting regulatory policies and fiscal incentives in shrimp- and salmon-producing counties, and enhancing restrictions on environmentally unsound practices.
Article
Full-text available
There is interest in certification of aquaculture production facilities in response to concerns about negative environmental and social impacts and food safety. This study identifies issues to be considered by stakeholders in developing certification standards for channel catfish, tilapias, rainbow trout, oysters, mussels, clams, scallops, abalone, and seaweed. Common issues include land and water use, water pollution, benthic effects, effects on biodiversity, use of antibiotics and other chemicals, and relationships with workers and local communities. Specific, contentious issues apply to individual species or species groups. Fish meal use in feeds will be a major concern in finfish certification. Use of groundwater, removal of daily mortalities, and medicated feed in channel catfish culture should be given particular attention. Tilapia culture can introduce these species into watersheds where they have not previously occurred, resulting in serious competition with native species. Some environmentalists and consumers object to hormone treatment of tilapia to produce all male fry. Widespread use of therapeutic agents in trout culture will be a major concern. Discussions of shellfish certification should focus on water use conflicts and public health risks associated with the consumption of these organisms. The introduction of non-native species and genetic alterations with respect to oysters also will need to be addressed. Further, introduction of non-native species should be a major topic in discussions of abalone and seaweed culture. The source of wild seaweed to use as food in abalone culture also will be an issue.
Article
Full-text available
Mangroves, the only woody halophytes living at the confluence of land and sea, have been heavily used traditionally for food, timber, fuel and medicine, and presently occupy about 181 000 km2 of tropical and subtropical coastline. Over the past 50 years, approximately one-third of the world's mangrove forests have been lost, but most data show very variable loss rates and there is considerable margin of error in most estimates. Mangroves are a valuable ecological and economic resource, being important nursery grounds and breeding sites for birds, fish, crustaceans, shellfish, reptiles and mammals; a renewable source of wood; accumulation sites for sediment, contaminants, carbon and nutrients; and offer protection against coastal erosion. The destruction of mangroves is usually positively related to human population density. Major reasons for destruction are urban development, aquaculture, mining and overexploitation for timber, fish, crustaceans and shellfish. Over the next 25 years, unrestricted clear felling, aquaculture, and overexploitation of fisheries will be the greatest threats, with lesser problems being alteration of hydrology, pollution and global warming. Loss of biodiversity is, and will continue to be, a severe problem as even pristine mangroves are species-poor compared with other tropical ecosystems. The future is not entirely bleak. The number of rehabilitation and restoration projects is increasing worldwide with some countries showing increases in mangrove area. The intensity of coastal aquaculture appears to have levelled off in some parts of the world. Some commercial projects and economic models indicate that mangroves can be used as a sustainable resource, especially for wood. The brightest note is that the rate of population growth is projected to slow during the next 50 years, with a gradual decline thereafter to the end of the century. Mangrove forests will continue to be exploited at current rates to 2025, unless they are seen as a valuable resource to be managed on a sustainable basis. After 2025, the future of mangroves will depend on technological and ecological advances in multi-species silviculture, genetics, and forestry modelling, but the greatest hope for their future is for a reduction in human population growth.
Article
Full-text available
We review estimates of the spatial ecosystem support required to run a typical semi-intensive shrimp farm in a coastal mangrove area in Carribean Colombia, and to produce food inputs and process wastes for large-scale industrially managed tilapia cage culture and small-scale, semi-intensive tilapia pond farming in Lake Kariba, Zimbabwe. The tilapia farming is discussed in relation to the pelagic kapenta, Limnothrissa miodon (Boulenger), fishery and to inshore fisheries in the Lake. The results show that a semi-intensive shrimp farm needs a spatial ecosystem support?the ecological footprint?35 to 190 times the surface area of the pond, mainly mangrove area. Based on the analysis, we conclude that shrimp farming in Colombia is already utilizing close to the full support capacity of its coastal environment. In intensive tilapia cage farming, the ecological footprint for feed production is 10 000 times larger than the area of the cages. In contrast, a tilapia pond farm maintained on offals from fisheries, agriculture and households depends very little on external ecosystem areas. As long as there is a direct market for human consumption of all kapenta caught in the Lake, fish cage farming based on fish meal from kapenta would be doubtful from ethical, ecological as well as resource management points of view, even if it was economically feasible.
Article
Full-text available
Using a Ricker (1975) model and escapement data for a subset of Broughton Archipelago, British Columbia watersheds, Krkošek et al. (2007a) predicted that sea lice infections originating on Atlantic salmon (Salmo salar)farms will cause the extinction of pink salmon (Oncorhynchus gorbuscha) in the archipelago by 2010. The purpose of this article is to examine this issue in the context of all of the escapement data available for the archipelago and to review additional scientific reports and information not discussed by Krkošek et al. (2007a). Additional research during the last five years is not consistent with the Krkošek et al. (2007a) conclusion that sea lice routinely cause in excess of 80% mortality of fry. Rather, the literature reviewed herein indicates that pink salmon fry mount an effective immune response at sizes as small as 0.7 g, resulting in the rapid shedding of lice within two weeks. Pink salmon returns are shown to be highly variable throughout the Northeast Pacific in areas without salmon farms. Following periods of high abundance, pink salmon populations typically fall to low levels, and they may remain depressed for several generations. However, in most cases, the populations then gradually increase to begin the cycle anew. An examination of returns to all of the documented Broughton Archipelago watersheds indicates that following exceptionally high returns in 2000 and 2001, the populations declined to very low numbers in 2002 and 2003. Contrary to the conclusions reached by Krkošek et al. (2007a), Broughton pink salmon returns have steadily increased since then, with no indication that they are threatened with extinction. Other unsubstantiated assumptions used in Krkošek et al. (2007a) are also discussed in light of additional scientific reports and theoretical considerations.
Article
Full-text available
Significant efforts should be devoted to reducing waste outputs from aquaculture operations in order to lower the environmental impacts of aquaculture in many parts of the world. Since most aquaculture wastes are ultimately from dietary origin, reduction of waste outputs should first be through improvements of diet formulation and feeding strategies. The first step in the production of feeds producing less solid waste is to eliminate poorly digestible ingredients (such as whole grain or grain by-products used as binders and fillers in the feed formulae) and to use highly digestible ingredients with good binding properties. Further reduction of solid waste can then be achieved through careful selection of the ingredients to improve apparent digestibility and the nutrient balance of the feed. Nitrogen waste outputs can be reduced through the reduction of the digestible protein to digestible energy (DP/DE) ratio of the diet. Phosphorus waste outputs can be reduced through careful selection of the ingredients and optimization of the digestible phosphorus content of the diet to meet the requirement of the fish but avoid greatly exceeding this required level. Finally, feeding practices that minimize feed wastage should be adopted since feed wastage can have a very significant impact on waste outputs from fish culture operations.
Article
Full-text available
Rising demand for shrimp in the developed nations has helped to foster a dramatic growth in marine shrimp aquaculture, particularly in South America and South Asia. In Thailand, Marine shrimp aquaculture is now an important earmer of foreign exchange. The growth in Production has been achieved through the expansion of the culture area and the adoption of intensive production methods. The conversion of near-shore areas to shrimp culture, however, is proving to have many consequences that impinge on the environmental integrity of coastal areas. This paper reviews the development of Thailand's marine shrimp culture industry and examines the nature of the environmental impacts that are emerging. It then discusses the implications these have for rural poor and the long-term viability of the culture industry.
Article
Full-text available
Goal, Scope and BackgroundIn face of continued declines in global fisheries landings and concurrent rapid aquaculture development, the sustainability of seafood production is of increasing concern. Life Cycle Assessment (LCA) offers a convenient means of quantifying the impacts associated with many of the energetic and material inputs and outputs in these industries. However, the relevant but limited suite of impact categories currently used in most LCA research fails to capture a number of important environmental and social burdens unique to fisheries and aquaculture. This article reviews the impact categories used in published LCA research of seafood production to date, reports on a number of methodological innovations, and discusses the challenges to and opportunities for further impact category developments. Main FeaturesThe range of environmental and socio-economic impacts associated with fisheries and aquaculture production are introduced, and both the commonly used and innovative impact categories employed in published LCA research of seafood production are discussed. Methodological innovations reported in agricultural LCAs are also reviewed for possible applications to seafood LCA research. Challenges and options for including additional environmental and socioeconomic impact categories are explored. ResultsA review of published LCA research in fisheries and aquaculture indicates the frequent use of traditional environmental impact categories as well as a number of interesting departures from the standard suite of categories employed in LCA studies in other sectors. Notable examples include the modeling of benthic impacts, by-catch, emissions from anti-fouling paints, and the use of Net Primary Productivity appropriation to characterize biotic resource use. Socio-economic impacts have not been quantified, nor does a generally accepted methodology for their consideration exist. However, a number of potential frameworks for the integration of such impacts into LCA have been proposed. DiscussionLCA analyses of fisheries and aquaculture call attention to an important range of environmental interactions that are usually not considered in discussions of sustainability in the seafood sector. These include energy use, biotic resource use, and the toxicity of anti-fouling paints. However, certain important impacts are also currently overlooked in such research. While prospects clearly exist for improving and expanding on recent additions to environmental impact categories, the nature of the LCA framework may preclude treatment of some of these impacts. Socio-economic impact categories have only been described in a qualitative manner. Despite a number of challenges, significant opportunities exist to quantify several important socio-economic impacts. ConclusionThe limited but increasing volume of LCA research of industrial fisheries and aquaculture indicates a growing interest in the use of LCA methodology to understand and improve the sustainability performance of seafood production systems. Recent impact category innovations, and the potential for further impact category developments that account for several of the unique interactions characteristic of fisheries and aquaculture will significantly improve the usefulness of LCA in this context, although quantitative analysis of certain types of impacts may remain beyond the scope of the LCA framework. The desirability of incorporating socio-economic impacts is clear, but such integration will require considerable methodological development. Recommendations and PerspectivesWhile the quantity of published LCA research for seafood production systems is clearly increasing, the influence this research will have on the ground remains to be seen. In part, this will depend on the ability of LCA researchers to advance methodological innovations that enable consideration of a broader range of impacts specific to seafood production. It will also depend on the ability of researchers to communicate with a broader audience than the currently narrow LCA community.
Article
Full-text available
Goal and Scope The goal of this study is to explore the potentials and limitations of using LCA as the basis for setting ecolabelling criteria in developing countries. The practicality of using LCA for this purpose, as required by ISO 14020, has been criticised as lacking in transparency and scientific rigour. Furthermore, ecolabelling is not widespread in developing countries. The application of LCA has therefore been illustrated by using the specific case of shrimp aquaculture in Thailand, as a basis for ecolabelling criteria for a typical product intended for export from a developing country. Method For the LCA case study, the functional unit is the standard consumer-package size, containing 1.8 kg of frozen shrimp produced by conventional intensive aquaculture in Thailand, subject to an appropriate environmental management system. The impact assessment method used in this study is CML 2 Baseline 2000. Results According to the results from the LCA study, farming appears to be the key life cycle stage generating the most significant environmental impacts: abiotic depletion and global warming, which arise mainly from the use of energy; and eutrophication caused by wastewater discharged from the shrimp ponds. It is possible to cover these impacts by quantitative ecolabelling criteria. Other important impacts could not be quantified by the LCA: depletion of wild shrimp broodstock, impacts of trawling on marine biodiversity and the choice of suitable farm sites. These impacts, which are also related to the farming stage, must be covered by 'hurdle criteria'. Conclusions and recommendations. For the present case, LCA provides a basis for quantifying a number of important ecolabelling criteria related to the use of abiotic resources and to emissions. Other important issues, connected with the use of biotic natural resources and land, are not quantifiable by current LCA methodology, but were also revealed and clarified by using an LCA framework for the analysis. Thus, focussing the assessment on life cycle considerations, as required by ISO 14024, was effective in identifying all key environmental issues. In the light of this case study, main limitations and barriers associated with the application of LCA to setting ecolabelling criteria particularly in developing countries are discussed, including recommendations on how to overcome them.
Article
Full-text available
The species composition, abundance and diversity of demersal fish assemblages has been investigated in an oligotrophic coastal bay in the Aegean Sea which is a designated zone for the development of aquaculture. Samples were collected using experimental trawling, before the establishment of fish cages in the area during early June 1987 and after attaining the maximal production of the aquaculture zone in late May 2001. The overall abundance of the fish assemblage increased by a factor of 4 and the average trophic level of the fish community increased from 3.59 to 3.79. Traditional diversity indices showed an increase in dominance but the distinctness measures of biodiversity showed that the overall structure obtained after the establishment of fish farming was not phylogenetically impoverished. Multivariate analysis showed that the community differences between the two periods are quantitative rather than qualitative. Comparisons in length frequencies between the two periods indicated that specimens of the species compared were either similar or larger in the second period. The species favoured by the presence of aquaculture were not the ones normally feeding on the food pellets under the cages but those normally occurring in the fishing grounds of the study. It is concluded that the release of nutrients from fish farming in nutrient-poor systems can have a positive effect on local fisheries with no visible negative change in species composition or biodiversity.
Article
Full-text available
This paper reviews and discusses, from an ecological perspective, the causes behind the development and spreading of pathogens in shrimp aquaculture. The risk of disease in shrimp farming often increases with culture intensity and high stocking densities, and when polyculture is replaced by monoculture. High pond densities will facilitate the spread of pathogens between ponds. Shortage of clean water supply and insufficient waste removal lead to overloading of metabolites, environmental degradation, and to the shrimp becoming stressed by bad water quality, and thus more prone to becoming affected by disease. Excessive fluctuations in abiotic factors like oxygen, salinity, and temperature may also increase stress and susceptibility to disease. The location of farms in mangrove environments can lead to acidification that may directly, or indirectly, through release of heavy metals from the sediments, lower disease resistance. The use of hatchery-reared larvae will increase genetic uniformity and thus disease risk in comparison to the collection of wild larvae where selection has already favored the most viable individuals. Global and regional transportation of seed larvae and broodstock will facilitate the spread of pathogens. Apart from the above factors, which are all dependant on the farming itself, contamination by pesticides and pollutants from agriculture and industrial activities may lower disease resistance of the shrimp, especially if combined with other environmental factors.
Article
Full-text available
The hypothesis that the presence of fish farms affects the communities of wild fish at large spatial scales was investigated through experimental trawl surveys. Three regions of the Aegean Sea with aquaculture zones were sampled in May and September (reproductive and recruitment periods, respectively for most species in the Aegean Sea). In each region, 2 sub-areas were sampled: 1 located nearby the fish farming zones (within 2 to 3 n mile) and a similar site (‘reference site’) far away from these zones (>20 n mile). Three replicate hauls were made in each sub-area for each of the 3 investigated regions. Significant differences were observed in community structure between farming and reference sites, which were mainly due to quantitative rather than qualitative aspects. The overall abundance and/or biomass of wild demersal fish was significantly higher near the fish farms in every region studied during May without any significant change in diversity or biodiversity. During the recruitment period in September, total abundance and biomass were fairly similar. These findings support the hypothesis that the presence of fish farms affects the wild fish populations in the oligotrophic eastern Mediterranean at a spatial scale larger than the immediate vicinity of fish cages. It seems that during the recruitment period all sites were stocked with fish close to the carrying capacity of the respective areas, and by late spring the areas close to fish farming zones had suffered little losses during winter, whereas populations at the reference sites had decreased substantially.
Article
Full-text available
1. The common name 'tilapia' refers to a group of tropical freshwater .sh in the family Cichlidae (Oreochromis, Tilapia, and Sarotherodon spp.) that are indigenous to Africa and the southwestern Middle East. Since the 1930s, tilapias have been intentionally dispersed worldwide for the biological control of aquatic weeds and insects, as bait.sh for certain capture .sheries, for aquaria, and as a food .sh. They have most recently been promoted as an important source of protein that could provide food security for developing countries without the environmental problems associated with terrestrial agriculture. In addition, market demand for tilapia in developed countries such as the United States is growing rapidly. 2. Tilapias are well-suited to aquaculture because they are highly proli.c and tolerant to a range of environmental conditions. They have come to be known as the 'aquatic chicken' because of their potential as an a.ordable, high-yield source of protein that can be easily raised in a range of environments } from subsistence or 'backyard' units to intensive .sh hatcheries. In some countries, particularly in Asia, nearly all of the introduced tilapias produced are consumed domestically; tilapias have contributed to basic food security for such societies. 3. This review indicates that tilapia species are highly invasive and exist under feral conditions in every nation in which they have been cultured or introduced. Thus, the authors have concluded that, despite potential or observed bene.ts to human society, tilapia aquaculture and open-water introductions cannot continue unchecked without further exacerbating damage to native .sh species and biodiversity. Recommendations include restricting tilapia culture to carefully managed, contained ponds, although exclusion is preferred when it is feasible. Research into culture of indigenous species is also recommended. Yes Yes
Book
Full-text available
Using a state-of-the art computer model of global supply and demand for food and feed commodities, this book projects the likely changes in the fisheries sector over the next two decades. As prices for most food commodities fall, fish prices are expected to rise, reflecting demand for fish that outpaces the ability of the world to supply it. The model shows that developing countries will consume and produce a much greater share of the world's fish in the future, and trade in fisheries commodities will also increase. The authors show the causes and implications of these and other changes, and argue for specific actions and policies that can improve outcomes for the poor and for the environment.
Article
Full-text available
Theory predicts that systems that are more diverse should be more resistant to exotic species, but experimental tests are needed to verify this. In experimental communities of sessile marine invertebrates, increased species richness significantly decreased invasion success, apparently because species-rich communities more completely and efficiently used available space, the limiting resource in this system. Declining biodiversity thus facilitates invasion in this system, potentially accelerating the loss of biodiversity and the homogenization of the world's biota.
Article
Full-text available
Farm Atlantic salmon escape and invade rivers throughout the North Atlantic annually, which has generated growing concern about their impacts on native salmon populations. A large-scale experiment was therefore undertaken in order to quantify the lifetime success and interactions of farm salmon invading a Norwegian river. Sexually mature farm and native salmon were genetically screened, radio tagged and released into the River Imsa where no other salmon had been allowed to ascend. The farm fishes were competitively and reproductively inferior, achieving less than one-third the breeding success of the native fishes. Moreover, this inferiority was sex biased, being more pronounced in farm males than females, resulting in the principal route of gene flow involving native males mating with farm females. There were also indications of selection against farm genotypes during early survival but not thereafter. However, evidence of resource competition and competitive displacement existed as the productivity of the native population was depressed by more than 30%. Ultimately, the lifetime reproductive success (adult to adult) of the farm fishes was 16% that of the native salmon. Our results indicate that such annual invasions have the potential for impacting on population productivity, disrupting local adaptations and reducing the genetic diversity of wild salmon populations.
Article
Full-text available
Over 75% of the world marine fisheries catch (over 80 million tonnes per year) is sold on international markets, in contrast to other food commodities (such as rice). At present, only one institution, the Food and Agriculture Organization of the United Nations (FAO) maintains global fisheries statistics. As an intergovernmental organization, however, FAO must generally rely on the statistics provided by member countries, even if it is doubtful that these correspond to reality. Here we show that misreporting by countries with large fisheries, combined with the large and widely fluctuating catch of species such as the Peruvian anchoveta, can cause globally spurious trends. Such trends influence unwise investment decisions by firms in the fishing sector and by banks, and prevent the effective management of international fisheries.