EarthTrends: Featured Topic Title Farming Fish: The Aquaculture Boom Author(s): Greg Mock, Robin White, and Amy Wagener Editor. Wendy vanasselt World Resources 1998-99, updated for EarthTrends Date written: 1998, updated July 2001 Aquaculture--the farming of 1997: 11; FAO 200033; FAO virtually all farmed fish are fish, shrimp, shellfish, and 2001 used as human food. Today, seaweeds- -has been a source Globally more than 25 nearly one-third of the fish of human protein for nearly percent of all fish and shellfish consumed by humans is the 4,000 years, especially in Asia production in 1999 was product of aquaculture, and wama1991:176-216) attributable to aquaculture, or that percentage will only Unprecedented growth in about 33 million metric tons increase as aquaculture aquaculture production in the (not counting seaweeds) out of expands and the world's last decade, however, has given 125 million metric tons(FAO conventional fish catch from it increased importance in the 2000a: 6).(See Figure 1). Yet oceans and lakes continues to modern food supply. World this industry's contribution to decline because of overfishing aquaculture production has the human diet is actually and environmental damage increased more than 300 greater than the numbers (FAO 2000b: 172; OECD percent since 1984, with imply. Whereas one-third of 2001: 112). As currently growth of about 10 percent a the conventional fish catch iced. ho year in the 1990s, making it the used to make fishmeal and fish aquaculture also causes fastest-growing food oil(FAO 1997: 4, 5; FAO environmental damage, raising production activity(FAO 2000a: 6) for animal feeds questions about how best to meet food demands and Farmed Fish Are a Growing Share of the Global Fish Harvest preserve environmental quality Figure 1: Aquaculture Producton as a Share of Total Marine and Freshwater Fish Haryest, 1970-1999 What Fish are farmed and Where? 160.0 140.0 Asia dominates world aquaculture, producing almost 120.0 90 percent of all farmed fish g100.0 shrimp, and shellfish(FAO 2000b: 173). China is by far the 80.0 leading producer, contributing 60.0 early 70 percent of 1999 million metric tons(FAO22 world pro 20.0 2001). Indeed, aquaculture 0.0 accounts for more than half of 19701974197819821986199019941998 China's total fish production each year(FAO 1997: 11-13) Total Capture O Total Aquaculture India is the second largest producer, with about 6 percent Source: FISHSTAT 2001 of the worlds aquaculture total OEarthTrends 2001 World Resources Institute. All rights reserved. Fair ed on a limited scale and for educational
©EarthTrends 2001 World Resources Institute. All rights reserved. Fair use is permitted on a limited scale and for educational purposes. EarthTrends: Featured Topic Title: Farming Fish: The Aquaculture Boom Author(s): Greg Mock, Robin White, and Amy Wagener Editor: Wendy Vanasselt Source: World Resources 1998-99, updated for EarthTrends Date written: 1998, updated July 2001 Aquaculture—the farming of fish, shrimp, shellfish, and seaweeds—has been a source of human protein for nearly 4,000 years, especially in Asia (Iwama 1991:176-216). Unprecedented growth in aquaculture production in the last decade, however, has given it increased importance in the modern food supply. World aquaculture production has increased more than 300 percent since 1984, with growth of about 10 percent a year in the 1990s, making it the fastest-growing food production activity (FAO 1997:11; FAO 2000a:3; FAO 2001). Globally, more than 25 percent of all fish and shellfish production in 1999 was attributable to aquaculture, or about 33 million metric tons (not counting seaweeds) out of 125 million metric tons (FAO 2000a:6). (See Figure 1). Yet this industry's contribution to the human diet is actually greater than the numbers imply. Whereas one-third of the conventional fish catch is used to make fishmeal and fish oil (FAO 1997:4,5; FAO 2000a:6) for animal feeds, virtually all farmed fish are used as human food. Today, nearly one-third of the fish consumed by humans is the product of aquaculture, and that percentage will only increase as aquaculture expands and the world's conventional fish catch from oceans and lakes continues to decline because of overfishing and environmental damage (FAO 2000b:172; OECD 2001:112). As currently practiced, however, aquaculture also causes environmental damage, raising questions about how best to meet food demands and preserve environmental quality. What Fish Are Farmed and Where? Asia dominates world aquaculture, producing almost 90 percent of all farmed fish, shrimp, and shellfish (FAO 2000b:173). China is by far the leading producer, contributing nearly 70 percent of 1999 world production, or about 22 million metric tons (FAO 2001). Indeed, aquaculture accounts for more than half of China's total fish production each year (FAO 1997:11-13). India is the second largest producer, with about 6 percent of the world's aquaculture total
1999(FAO2001) China Dominates Word Aquaculture sing even as many ocean see Figure 2) Figure 2: Top Nine Countries for Global stocks are declining, and Aquaculture Aquaculture Production aquaculture techniques and products fall into two SHARE OF GLOBAL technology continue to distinct groups: high- COUNTRY PRODUCTION improve. In addition, smal valued species such as 70.2 scale aquaculture offers rimp and salmon that India 48% farmers a ready source of frequently grown Japan 3,1% both subsistence food and or ex 22% cash and these benefits are valued species such likely to promote expansion carp and tilapia that are Korea, Republic of 1.8% beyond its traditional 1.6% Cons rimar tronghold in Asia(FAO locally. China, fo 14% 1997:24-25 instance, raises a Viet Nam 14% However, substantial amount of 14% serious constraints on shrimp and marine fish Other countries 12.09 aquaculture's growth For like flounder、sea one, fish farming requires bream. mullet. and Source: FISHSTAT 2001 both land and water-two puffer fish in intensively resources already in short naged ponds along its easier to integrate with other supply in many areas.In coastline for the lucrative conventional farm activities Thailand both these resources export trade( Gujja and Finger- than are other types of have been diverted in recent Stich1996:12-14,33;Guo aquaculture. Whereas farmed years to fuel the growth of the 2000: 2). Yet China's total shrimp tend to grace the tables aquaculture industry.For aquaculture production is of consumers in high-income ole, nearly half the land dominated not by shrimp but regions like Japan, Europe, and now used for shrimp ponds in by carp raised in relatively low- the United States, carp make a Thailand was formerly used for tech inland ponds for local direct, significant contribution rice paddies; in addition,water consumption. The four major to the protein needs of less diversion for carp species--silver carp, grass affluent rural Chinese(FAO lowered groundwater levels 1997:59; Holmes1996:34) oticeably in some coastal 1ghead carp--account for A e's limitations areas In China. the concern more than one-third of world Can continued expansion of over loss of arable land has led aquaculture production- nearly all of it in China(FAo fish catch enough to feed the conversion of farmland to 1997:11-12 world's growing need for fish aquaculture ponds(Holmes are raise protein? Certainly, some 6:35-36) primarily as a supplementary growth in world aquaculture More serious still are the activity to regular crop can be expected, but just how environmental impacts of agriculture on Chinese farms. much is not clear. One analysis aquaculture operations herbivores and can projects that global production especially the inter nsive survive on low-cost, readily ould nearly double by 2020 to production systems and larg available feed material, rather 70 million metric tons(OECD scale facilities used to raise than on the high-cost fishmeal 2001: 112-113).Several facto high-value shrimp, salmon, and that carnivorous species such are pushing this growth in both other premium species. Shrimp shrimp and salmon require intensive aquaculture and in farming has taken an especially to grow; thus carp farming is small-scale, farm-based efforts. heavy toll on coastal habitats both more economical and Global demand for fish is with mangrove swamps in OEarthTrends 2001 World Resources Institute. All rights reserved. Fair ed on a limited scale and for educational
©EarthTrends 2001 World Resources Institute. All rights reserved. Fair use is permitted on a limited scale and for educational purposes. 2 in 1999 (FAO 2001 ) (see Figure 2). Aquaculture products fall into two distinct groups: highvalued species such as shrimp and salmon that are frequently grown for export, and lowervalued species such as carp and tilapia that are consumed primarily locally. China, for instance, raises a substantial amount of shrimp and marine fish like flounder, sea bream, mullet, and puffer fish in intensively managed ponds along its coastline for the lucrative export trade (Gujja and FingerStich 1996:12-14, 33; Guo 2000:2). Yet China's total aquaculture production is dominated not by shrimp but by carp raised in relatively lowtech inland ponds for local consumption. The four major carp species—silver carp, grass carp, common carp, and bighead carp—account for more than one-third of world aquaculture production— nearly all of it in China (FAO 1997:11-12). These carp are raised primarily as a supplementary activity to regular crop agriculture on Chinese farms. Carp are herbivores and can survive on low-cost, readily available feed material, rather than on the high-cost fishmeal that carnivorous species such as shrimp and salmon require to grow; thus carp farming is both more economical and easier to integrate with other conventional farm activities than are other types of aquaculture. Whereas farmed shrimp tend to grace the tables of consumers in high-income regions like Japan, Europe, and the United States, carp make a direct, significant contribution to the protein needs of less affluent rural Chinese (FAO 1997:59; Holmes 1996:34). Aquaculture's Limitations Can continued expansion of aquaculture increase the global fish catch enough to feed the world's growing need for fish protein? Certainly, some growth in world aquaculture can be expected, but just how much is not clear. One analysis projects that global production could nearly double by 2020 to 70 million metric tons (OECD 2001:112-113). Several factors are pushing this growth in both intensive aquaculture and in small-scale, farm-based efforts. Global demand for fish is rising even as many ocean stocks are declining, and aquaculture techniques and technology continue to improve. In addition, smallscale aquaculture offers farmers a ready source of both subsistence food and cash, and these benefits are likely to promote expansion beyond its traditional stronghold in Asia (FAO 1997:24-25). However, there are also serious constraints on aquaculture's growth. For one, fish farming requires both land and water—two resources already in short supply in many areas. In Thailand both these resources have been diverted in recent years to fuel the growth of the aquaculture industry. For example, nearly half the land now used for shrimp ponds in Thailand was formerly used for rice paddies; in addition, water diversion for shrimp ponds has lowered groundwater levels noticeably in some coastal areas. In China, the concern over loss of arable land has led to restrictions on any further conversion of farmland to aquaculture ponds (Holmes 1996:35-36). More serious still are the environmental impacts of aquaculture operations, especially the intensive production systems and largescale facilities used to raise high-value shrimp, salmon, and other premium species. Shrimp farming has taken an especially heavy toll on coastal habitats, with mangrove swamps in
Africa and Southeast asia lease of about 100 kg of impacts of aquaculture. Fc being cleared at an alarming nitrogenous compounds, like example, several countries rate to make room for shrimp ammonia, into nearby waters where salmon are farmed have ponds(gujja and Finger-Stich(Roth 2000: 38). Nutrient instituted controls on 1996:12-15,33-39; Iwama pollution from aquaculture, in production to ensure that 1991: 192-216) In just 6 years, turn, can cause declines in pollution is kept within from 1987 to 1993, Thailand aquaculture productivity by acceptable limitsFAO lost more than 17 percent of its promoting outbreaks of disease 1997: 22). In some cases, new mangrove forests to shrimp among the fish(Naylor et al. technology has also helped In ponds(olmes 1996: 36) 20008) Puget Sound, on the west coast Destruction of mangroves Paradoxically, some of the United States, of leaves coastal areas exposed to aquaculture production also salmon farmer is using a giant, erosion and flooding, and has puts more pressure on ocean floating, semienclosed tub to altered natural drainage fish stocks, rather than raise his fish rather than the patterns, increased salt relieving pressure. As noted usual porous pens made of intrusion. and removed a previously, carnivorous species netting. The tub prevents fish critical habitat for many aquatic like salmon and shrimp depend wastes from polluting species(Iwama 1991: 177-216). on high-protein feed ding waters and also According to one estimate, for formulated from fishmeal-a keeps fish from escaping and every kilogram of shrimp blend of sardines. anchovies intermingling with wild farmed in Thai shrimp ponds pilchard, and other low-value salmon, which would developed in mangroves, 400 g fish. But it is also becoming contaminate the gene pool of of fish and shrimp are los more common, especially in the native fish(Christensen from wild captured fisheries Asia, to boost the weights of 1997: 27-29). Integrating the aylor et al. 2000: 6) herbivorous and omnivorous production of fish and other Intensive aquaculture ish by giving them feed that marine products, like seaweed operations can also lead to contains as much as 15 percent and mussels that grow well water shortages and pollution. fish meal and fish oil. There wastewater from intensive farm requires 50-60 thousand addition of extra fish meal and nutrient and particulate load Raising 1 ton of shrimp in a are growing concerns that the farms, can also help reduce th litres of water (Anonymous oil could place significan In Chile. some salmon are 1997: 109). When that water is pressure on the pelagic farmed with a red alga that flushed from the ponds into fisheries and marine removes nitrogen and surrounding coastal or river ecosystems that supply it phosphorous wastes from the waters in exchange for fresh (Naylor et aL. 2000: 4, 8). By cages. The effluent can also be applies. its heay some estimates, as much as 33 d to produ concentrations of fish feces, percent of fishmeal is used for crop, offsetting the costs of uneaten food. and other aquaculture feeds, and it takes creating the integrated farming organic debris can lead to ughly 2 kg of fishmeal to system(Naylor 2001: 9) oxygen depletion and produce a kg of farmed fish or Even in the problematic contribute to harmful algal shrimp. The result is a net loss shrimp-farming industry, there blooms In Thailand alone of fish protein (Naylor et al. re some initial signs of hrimp ponds discharge some 2000: 4-5) progress. In South Asia,a 1.3 billion m of effluent into The Food and Agriculture major shrimp producer has coastal waters each year Organization of the United instituted a temporary ban on Holmes1996:3435).In Nations(FAO)asserts that ew ponds until the Scotland, producing a ton of some progress has been made government adopts an farmed salmon results in the in reducing the environmental acceptable social and OEarthTrends 2001 World Resources Institute. All rights reserved. Fair ed on a limited scale and for educational
©EarthTrends 2001 World Resources Institute. All rights reserved. Fair use is permitted on a limited scale and for educational purposes. 3 Africa and Southeast Asia being cleared at an alarming rate to make room for shrimp ponds (Gujja and Finger-Stich 1996:12-15, 33-39; Iwama 1991:192-216). In just 6 years, from 1987 to 1993, Thailand lost more than 17 percent of its mangrove forests to shrimp ponds (Holmes 1996:36). Destruction of mangroves leaves coastal areas exposed to erosion and flooding, and has altered natural drainage patterns, increased salt intrusion, and removed a critical habitat for many aquatic species (Iwama 1991:177-216). According to one estimate, for every kilogram of shrimp farmed in Thai shrimp ponds developed in mangroves, 400 g of fish and shrimp are lost from wild captured fisheries (Naylor et al. 2000:6). Intensive aquaculture operations can also lead to water shortages and pollution. Raising 1 ton of shrimp in a farm requires 50-60 thousand litres of water (Anonymous 1997:109). When that water is flushed from the ponds into surrounding coastal or river waters in exchange for fresh supplies, its heavy concentrations of fish feces, uneaten food, and other organic debris can lead to oxygen depletion and contribute to harmful algal blooms. In Thailand alone, shrimp ponds discharge some 1.3 billion m³ of effluent into coastal waters each year (Holmes 1996:34-35). In Scotland, producing a ton of farmed salmon results in the release of about 100 kg of nitrogenous compounds, like ammonia, into nearby waters (Roth 2000:38). Nutrient pollution from aquaculture, in turn, can cause declines in aquaculture productivity by promoting outbreaks of disease among the fish (Naylor et al. 2000:8). Paradoxically, some aquaculture production also puts more pressure on ocean fish stocks, rather than relieving pressure. As noted previously, carnivorous species like salmon and shrimp depend on high-protein feed formulated from fishmeal—a blend of sardines, anchovies, pilchard, and other low-value fish. But it is also becoming more common, especially in Asia, to boost the weights of herbivorous and omnivorous fish by giving them feed that contains as much as 15 percent fish meal and fish oil. There are growing concerns that the addition of extra fish meal and oil could place significant pressure on the pelagic fisheries and marine ecosystems that supply it (Naylor et al. 2000:4, 8). By some estimates, as much as 33 percent of fishmeal is used for aquaculture feeds, and it takes roughly 2 kg of fishmeal to produce a kg of farmed fish or shrimp. The result is a net loss of fish protein (Naylor et al. 2000:4-5). The Food and Agriculture Organization of the United Nations (FAO) asserts that some progress has been made in reducing the environmental impacts of aquaculture. For example, several countries where salmon are farmed have instituted controls on production to ensure that pollution is kept within acceptable limits (FAO 1997:22). In some cases, new technology has also helped. In Puget Sound, on the west coast of the United States, one salmon farmer is using a giant, floating, semienclosed tub to raise his fish rather than the usual porous pens made of netting. The tub prevents fish wastes from polluting surrounding waters and also keeps fish from escaping and intermingling with wild salmon, which would contaminate the gene pool of the native fish (Christensen 1997:27-29). Integrating the production of fish and other marine products, like seaweed and mussels that grow well in wastewater from intensive farms, can also help reduce the nutrient and particulate loads. In Chile, some salmon are farmed with a red alga that removes nitrogen and phosphorous wastes from the cages. The effluent can also be used to produce a seaweed crop, offsetting the costs of creating the integrated farming system (Naylor 2001:9). Even in the problematic shrimp-farming industry, there are some initial signs of progress. In South Asia, a major shrimp producer has instituted a temporary ban on new ponds until the government adopts an acceptable social and
environment to help in the transition to low- In the end, aquaculture's 1997: 22). In some locales in impact, high-productivity fish contribution to the global food Thailand. farmers are farming. For example, Chinese supply will likely turn on how voluntarily coordinating the researchers are developing a ell these and other flushing and filling of ponds to protein supplement based on innovations can help fish farms reduce the spread of diseases. yeast that can substitute for more closely mimic natural In addition, some shrimp more than half the fishmeal in ecosystems, with better farmers are advocating an aquaculture feed preparations. recycling of nutrients and less ecolabeling"scheme that Further, work on fish breeding waste generation(Fc would certify shrimp grown by has already produced a strain Kautsky 1992: 5-24) producers using more benign of tilapia that grows 60 percent mean fewer inputs and farming practices(Christensen faster and with higher survival impacts, without eroding 1997:29) rates than native tilapia aquaculture's profitability and Progress in aquaculture Holmes1996:3435) versatility research can also be expected REFERENCES Anonymous. 1997. Aquaculture: A solution, or source of new problems? Nature 386(6621): 109 Christensen, J. 1997. Cultivating the worlds demand for seafood. The Ne York Times(New York City)( March1,1997):27-29 Folke, C and N. Kautsky. 1992. Aquaculture with its environment: Prospects for sustainability Ocean and Coastal Management 17(1): 5-24 Food and Agriculture Organization of the United Nations(FAO). 1997. The State of w orld Fisberie and aquaculture 1996. Rome: FAO Food and Agriculture Organization of the United Nations(FAO). 2000a. The State of the World Fisheries and aquaclture 2000. Rome: FAO Food and Agriculture Organization of the United Nations(FAO) Global Perspectives Unit. 2000b Agriculture: Towards 2015/30: Technical Interim Report. Rome: FAO.(April) Food and Agriculture Organization of the United Nations(FAO). 2001. FISHSTAT. Online at http://www.fao.org/fi/statist/fisoft/fishplus.asp Guo, X. 2000. Aquaculture in China: two decades of rapid growth. Aquaculture Magasine 26(3) Guja, B and A Finger-Stich. 1996. What price prawn? Shrimp aquacultures impact in Asia Entironment38(7)12-15,3-39 Holmes, B. 1996. Blue revolutionaries. New Scientist 152(2059): 32 OEarthTrends 2001 World Resources Institute. All rights reserved. Fair use is permitted on a limited scale and for educational I
©EarthTrends 2001 World Resources Institute. All rights reserved. Fair use is permitted on a limited scale and for educational purposes. 4 environmental policy (FAO 1997:22). In some locales in Thailand, farmers are voluntarily coordinating the flushing and filling of ponds to reduce the spread of diseases. In addition, some shrimp farmers are advocating an "ecolabeling" scheme that would certify shrimp grown by producers using more benign farming practices (Christensen 1997:29). Progress in aquaculture research can also be expected to help in the transition to lowimpact, high-productivity fish farming. For example, Chinese researchers are developing a protein supplement based on yeast that can substitute for more than half the fishmeal in aquaculture feed preparations. Further, work on fish breeding has already produced a strain of tilapia that grows 60 percent faster and with higher survival rates than native tilapia (Holmes 1996:34-35). In the end, aquaculture's contribution to the global food supply will likely turn on how well these and other innovations can help fish farms more closely mimic natural ecosystems, with better recycling of nutrients and less waste generation (Folke and Kautsky 1992:5-24). That will mean fewer inputs and impacts, without eroding aquaculture's profitability and versatility. REFERENCES Anonymous. 1997. Aquaculture: A solution, or source of new problems? Nature 386(6621):109. Christensen, J. 1997. Cultivating the world's demand for seafood. The New York Times (New York City) (March 1, 1997):27-29. Folke, C. and N. Kautsky. 1992. Aquaculture with its environment: Prospects for sustainability. Ocean and Coastal Management 17(1):5-24. Food and Agriculture Organization of the United Nations (FAO). 1997. The State of World Fisheries and Aquaculture 1996. Rome: FAO. Food and Agriculture Organization of the United Nations (FAO). 2000a. The State of the World Fisheries and Aquaculture 2000. Rome: FAO. Food and Agriculture Organization of the United Nations (FAO) Global Perspectives Unit. 2000b. Agriculture: Towards 2015/30: Technical Interim Report. Rome: FAO. (April). Food and Agriculture Organization of the United Nations (FAO). 2001. FISHSTAT. Online at: http://www.fao.org/fi/statist/FISOFT/FISHPLUS.asp. Guo, X. 2000. Aquaculture in China: two decades of rapid growth. Aquaculture Magazine 26(3). Gujja, B. and A. Finger-Stich. 1996. What price prawn? Shrimp aquaculture's impact in Asia. Environment 38(7):12-15, 33-39. Holmes, B. 1996. Blue revolutionaries. New Scientist 152(2059):32
rama, G.K. 1991. Interactions between aquaculture and the environment. Critical Reviews in Enironmental Control 21(2): 177-216 Naylor, R,, R. Goldburg, J. Primavera, N. Kautsky, M. Beveridge, J Clay, C. Folke,J Lubchenco, H Mooney, and M. Troll. 2000. Effect of aquaculture on world fish supplies. Nature 405: 1017-1024 Organization for Economic Cooperation and Development(OECD). 2001. OECD Emzronmental Outlook. Paris: OECD Roth, S. 2001. The horrors of intensive salmon farming. The Ecologist Special Issue. ( une EarthTrends 2001 World Resources Institute. All rights reserved. Fair use is permitted on a limited scale and for educational I
©EarthTrends 2001 World Resources Institute. All rights reserved. Fair use is permitted on a limited scale and for educational purposes. 5 Iwama, G. K. 1991. Interactions between aquaculture and the environment. Critical Reviews in Environmental Control 21(2):177-216. Naylor, R., R. Goldburg, J. Primavera, N. Kautsky, M. Beveridge, J. Clay, C. Folke, J. Lubchenco, H. Mooney, and M. Troll. 2000. Effect of aquaculture on world fish supplies. Nature 405:1017-1024. Organization for Economic Cooperation and Development (OECD). 2001. OECD Environmental Outlook. Paris: OECD. Roth, S. 2001. The horrors of intensive salmon farming. The Ecologist Special Issue. (June)
