Shrimp farm
Encyclopedia
A shrimp farm is an aquaculture
business for the cultivation of marine shrimp
or prawn
s for human consumption. Commercial shrimp farming began in the 1970s, and production grew steeply, particularly to match the market demands of the United States
, Japan
and Western Europe
. The total global production of farmed shrimp reached more than 1.6 million tonne
s in 2003, representing a value of nearly 9 billion U.S. dollars
. About 75% of farmed shrimp is produced in Asia
, in particular in China
and Thailand
. The other 25% is produced mainly in Latin America
, where Brazil
, Ecuador
, and Mexico
are the largest producers. The largest exporting nation is Thailand.
Shrimp farming has changed from traditional, small-scale businesses in Southeast Asia
into a global industry. Technological advances have led to growing shrimp at ever higher densities, and broodstock
is shipped worldwide. Virtually all farmed shrimp are of the family
Penaeidae
, and just two species – Penaeus vannamei
(Pacific white shrimp) and Penaeus monodon
(giant tiger prawn) – account for roughly 80% of all farmed shrimp. These industrial monoculture
s are very susceptible to diseases, which have caused several regional wipe-outs of farm shrimp populations. Increasing ecological problems, repeated disease outbreaks, and pressure and criticism from both NGOs
and consumer countries led to changes in the industry in the late 1990s and generally stronger regulation by governments. In 1999, a program aimed at developing and promoting more sustainable farming
practices was initiated, including governmental bodies, industry representatives, and environmental organizations.
n brackish water
ponds, called tambaks, can be traced back as far as the 15th century. They used small scale ponds for monoculture
or polyculture
d with other species, such as milkfish
, or in rotation with rice
, using the rice paddies
for shrimp cultures during the dry season, when no rice could be grown. Such cultures often were in coastal areas or on river banks. Mangrove
areas were favored because of their abundant natural shrimp. Wild juvenile shrimp were trapped in ponds and reared on naturally occurring organisms in the water until they reached the desired size for harvesting.
Industrial shrimp farming can be traced to the 1930s, when Japan
ese agrarians spawned and cultivated Kuruma shrimp (Penaeus japonicus) for the first time. By the 1960s, a small industry had developed in Japan. Commercial shrimp farming began to grow rapidly in the late 1960s and early 1970s. Technological advances led to more intensive forms of farming, and growing market demand led to worldwide proliferation of shrimp farms, concentrated in tropical and subtropical regions. Growing consumer demand in the early 1980s coincided with faltering wild catches, creating a booming industry. Taiwan
was an early adopter and a major producer in the 1980s; its production collapsed beginning in 1988 due to poor management practices and disease. In Thailand
, large-scale production expanded rapidly from 1985. In South America
, Ecuador
pioneered shrimp farming, where it expanded dramatically from 1978. Brazil had been active in shrimp farming since 1974, but trade boomed there only in the 1990s, making the country a major producer within a few years. Today, there are marine shrimp farms in over fifty countries.
s, ponds of sizes up to 100 hectare were used and huge areas of mangroves were cleared in some areas. Technological advances made more intensive practices possible that increase yield per area, helping reduce pressure to convert more land. Semi-intensive and intensive farms appeared, where the shrimp were reared on artificial feeds and ponds were actively managed. Although many extensive farms remain, new farms typically are of the semi-intensive kind.
Until the mid-1980s, most farms were stocked with young wild animals, called 'postlarvae', typically caught locally. Postlarvae fishing became an important economic sector in many countries. To counteract the depletion of fishing grounds and to ensure a steady supply of young shrimp, the industry started breeding shrimp in hatcheries
.
Shrimp mature and breed only in a marine habitat
. The females lay 50,000 to 1 million eggs, which hatch after some 24 hours into tiny nauplii. These nauplii feed on yolk reserves within their bodies, and then metamorphose into zoeae. Shrimp in this second larval stage feed in the wild on algae
, and after a few days, morph again into myses. The myses look akin to tiny shrimp, and feed on algae and zooplankton
. After another three to four days, they metamorphose a final time into postlarvae: young shrimp that have adult characteristics. The whole process takes about 12 days from hatching. In the wild, postlarvae then migrate into estuaries
, which are rich in nutrients and low in salinity
. They migrate back into open waters when they mature. Adult shrimp are benthic animals living primarily on the sea bottom.
s). There are three different stages:
Most farms produce one to two harvests a year; in tropical climates, even three are possible. Because of the need for salt water, shrimp farms are located on or near a coast. Inland shrimp farms have also been tried in some regions, but the need to ship salt water and competition for land with agricultural users led to problems. Thailand
banned inland shrimp farms in 1999.
Small-scale hatcheries are very common throughout Southeast Asia. Often run as family businesses and using a low-technology approach, they use small tanks (less than ten tons) and often low animal densities. They are susceptible to disease, but due to their small size, they can typically restart production quickly after disinfection. The survival rate is anywhere between zero and 90%, depending on a wide range of factors, including disease, the weather, and the experience of the operator.
Greenwater hatcheries are medium-sized hatcheries using large tanks with low animal densities. To feed the shrimp larvae, an algal bloom
is induced in the tanks. The survival rate is about 40%.
Galveston hatcheries (named after Galveston, Texas
, where they were developed) are large-scale, industrial hatcheries using a closed and tightly controlled environment. They breed the shrimp at high densities in large (15 to 30 ton) tanks. Survival rates vary between zero and 80%, but typically achieve 50%.
In hatcheries, the developing shrimp are fed on a diet of algae and later also brine shrimp
nauplii, sometimes (especially in industrial hatcheries) augmented by artificial diets. The diet of later stages also includes fresh or freeze-dried animal protein, for example krill
. Nutrition and medication (such as antibiotic
s) fed to the brine shrimp nauplii are passed on to the shrimp that eat them.
In a typical nursery, there are 150 to 200 animals per square metre. They are fed on a high-protein
diet for at most three weeks before they are moved to the growout ponds. At that time, they weigh between one and two grams. The water salinity is adjusted gradually to that of the growout ponds.
Farmers refer to postlarvae as "PLs", with the number of days suffixed (i.e., PL-1, PL-2, etc.). They are ready to be transferred to the growout ponds after their gill
s have branched, which occurs around PL-13 to PL-17 (about 25 days after hatching). Nursing is not absolutely necessary, but is favoured by many farms because it makes for better food utilization, improves the size uniformity, helps use the infrastructure better, and can be done in a controlled environment to increase the harvest. The main disadvantage of nurseries is that some of the postlarval shrimp die upon the transfer to the growout pond.
Some farms do not use a nursery, but stock the postlarvae directly in the growout ponds after having acclimated them to the appropriate temperature and salinity levels in an acclimation tank. Over the course of a few days, the water in these tanks is changed gradually to match that of the growout ponds. The animal density should not exceed 500/litre for young postlarvae and 50/liter for larger ones, such as PL-15.
Extensive shrimp farms using traditional low-density methods are invariably located on a coast and often in mangrove
areas. The ponds range from just a few to more than 100 hectare
s; shrimp are stocked at low densities (2–3 animals per square metre, or 25,000/ha). The tides provide for some water exchange, and the shrimp feed on naturally occurring organisms. In some areas, farmers even grow wild shrimp by just opening the gates and impounding wild larvae. Prevalent in poorer or less developed countries where land prices are low, extensive farms produce annual yields from 50 to 500 kg/ha of shrimp (head-on weight). They have low production costs (US$1–3/kg live shrimp), are not very labor intensive, and do not require advanced technical skills.
Semi-intensive farms do not rely on tide
s for water exchange, but use pumps and a planned pond layout. They can therefore be built above the high tide line. Pond sizes range from 2 to 30 ha; the stocking densities range from 10 to 30/square meter (100,000–300,000/ha). At such densities, artificial feeding using industrially prepared shrimp feeds and fertilizing the pond to stimulate the growth of naturally occurring organisms become a necessity. Annual yields range from 500 to 5,000 kg/ha, while production costs are in the range of US$2–6/kg live shrimp. With densities above 15 animals per square meter, aeration
is often required to prevent oxygen depletion. Productivity varies depending upon water temperature, thus it is common to have larger sized shrimp in some seasons than in others.
Intensive farms use even smaller ponds (0.1–1.5 ha) and even higher stocking densities. The ponds are actively managed: they are aerated, there is a high water exchange to remove waste products and maintain water quality, and the shrimp are fed on specially designed diets, typically in the form of formulated pellets. Such farms produce annual yields between 5,000 and 20,000 kg/ha; a few super-intensive farms can produce as much as 100,000 kg/ha. They require an advanced technical infrastructure and highly trained professionals for constant monitoring of water quality and other pond conditions; their production costs are in the range of US$4–8/kg live shrimp.
Estimates on the production characteristics of shrimp farms vary. Most studies agree that about 55–60% of all shrimp farms worldwide are extensive farms, another 25–30% are semi-intensive, and the rest are intensive farms. Regional variation is high, though, and [Tacon (2002)] reports wide discrepancies in the percentages claimed for individual countries by different studies.
is established in the ponds, based on the growth of phytoplankton
. Fertilizers and mineral conditioners are used to boost the growth of the phytoplankton to accelerate the growth of the shrimp. Waste from the artificial food pellets and shrimp excrement can lead to the eutrophication
of the ponds.
Artificial feeds come in the form of specially formulated, granulated pellets that disintegrate quickly. Up to 70% of such pellets are wasted, as they decay before the shrimp have eaten them. They are fed two to five times daily; the feeding can be done manually either from ashore or from boats, or using mechanized feeders distributed all over a pond. The feed conversion rate (FCR), i.e. the amount of food needed to produce a unit (e.g. one kilogram) of shrimp, is claimed by the industry to be around 1.2–2.0 in modern farms, but this is an optimum value that is not always attained in practice. For a farm to be profitable, a feed conversion rate below 2.5 is necessary; in older farms or under suboptimal pond conditions, the ratio may easily rise to 4:1. Lower FCRs result in a higher profit for the farm.
Penaeidae
), and within it to the genus Penaeus
. Many species are unsuitable for farming: they are too small to be profitable, or simply stop growing when crowded together, or are too susceptible to diseases. The two species dominating the market are:
Together, these two species account for about 80% of the whole farmed shrimp production. Other species being bred are:
Several other species of Penaeus play only a very minor role in shrimp farming. Some other kinds of shrimp also can be farmed, e.g. the "Akiami paste shrimp" or Metapenaeus spp. Their total production from aquaculture is of the order of only about 25,000 tonnes per year, small in comparison to that of the penaeids.
disease
s that affect shrimp. In the densely populated, monocultural
farms such virus infections spread rapidly and may wipe out whole shrimp populations. A major transfer vector of many of these viruses is the water itself; and thus any virus outbreak also carries the danger of decimating shrimp living in the wild.
Yellowhead disease
, called Hua leung in Thai
, affects P. monodon throughout Southeast Asia. It had been reported first in Thailand in 1990. The disease is highly contagious and leads to mass mortality within 2 to 4 days. The cephalothorax
of an infected shrimp turns yellow after a period of unusually high feeding activity ending abruptly, and the then moribund shrimp congregate near the surface of their pond before dying.
Whitespot syndrome is a disease caused by a family of related viruses. First reported in 1993 from Japanese P. japonicus cultures, it spread throughout Asia and then to the Americas. It has a wide host range and is highly lethal, leading to mortality rates of 100% within days. Symptoms include white spots on the carapace and a red hepatopancreas
. Infected shrimp become lethargic before they die.
Taura syndrome
was first reported from shrimp farms on the Taura river in Ecuador in 1992. The host of the virus causing the disease is P. vannamei, one of the two most commonly farmed shrimp. The disease spread rapidly, mainly through the shipping of infected animals and broodstock. Originally confined to farms in the Americas, it has also been propagated to Asian shrimp farms with the introduction of L. vannamei there. Birds are thought to be a route of infection between farms within one region.
Infectious hypodermal and hematopoietic necrosis
(IHHN) is a disease that causes mass mortality among P. stylirostris (as high as 90%) and severe deformations in L. vannamei. It occurs in Pacific farmed and wild shrimp, but not in wild shrimp on the Atlantic
coast of the Americas.
There are also a number of bacteria
l infections that are lethal to shrimp. The most common is vibriosis, caused by bacteria of the Vibrio
species. The shrimp become weak and disoriented, and may have dark wounds on the cuticle
. The mortality rate can exceed 70%. Another bacterial disease is necrotising hepatopancreatitis
(NHP); symptoms include a soft exoskeleton and fouling. Most such bacterial infections are strongly correlated to stressful conditions, such as overcrowded ponds, high temperatures, and poor water quality, factors that positively influence the growth of bacteria. Treatment is done using antibiotic
s. Importing countries have repeatedly placed import bans on shrimp containing various antibiotics. One such antibiotic is chloramphenicol
, which has been banned in the European Union
since 1994, but continues to pose problems.
With their high mortality rates, diseases represent a very real danger to shrimp farmers, who may lose their income for the whole year if their ponds are infected. Since most diseases cannot yet be treated effectively, the industry's efforts are focused on preventing disease outbreak in the first place. Active water quality management helps avoid poor pond conditions favorable to the spread of diseases, and instead of using larvae from wild catches, specific pathogen free
broodstock
s raised in captivity in isolated environments and certified not to carry diseases are used increasingly. To avoid introducing diseases into such disease-free populations on a farm, there is also a trend to create more controlled environments in the ponds of semi-intensive farms, such as by lining them with plastic to avoid soil contact, and by minimizing water exchange in the ponds.
s in 2005. This accounts for 42% of the total shrimp production that year (farming and wild catches combined). The largest single market for shrimp is the United States
, importing between 500 – 600,000 tonnes of shrimp products yearly in the years 2003-2009. About 200,000 tonnes yearly are imported by Japan
, while the European Union
imported in 2006 another about 500,000 tonnes of tropical shrimps, with the largest importers being Spain
and France
. The EU also is a major importer of coldwater shrimp from catches, mainly common shrimp (Crangon crangon
) and Pandalidae
such as Pandalus borealis
; in 2006, these imports accounted for about another 200,000 tonnes.
The import prices for shrimp fluctuate wildly. In 2003, the import price per kilogram
shrimp in the United States
was US$ 8.80, slightly higher than in Japan at US$8.00. The average import price in the EU was only about US$5.00/kg; this much lower value is explained by the fact that the EU imports more coldwater shrimp (from catches) that are much smaller than the farmed warm water species, and thus attain lower prices. In addition, Mediterranean Europe prefers head-on shrimp, which weigh approximately 30% more, but have a lower unit price.
About 75% of the world production of farmed shrimp comes from Asian countries; the two leading nations being China
and Thailand
, closely followed by Vietnam
, Indonesia
, and India
. The other 25% are produced in the western hemisphere, where Latin American countries (Brazil
, Ecuador
, Mexico
) dominate. In terms of export, Thailand is by far the leading nation, with a market share of more than 30%, followed by China, Indonesia, and India, accounting each for about 10%. Other major export nations are Vietnam, Bangladesh, and Ecuador. Thailand exports nearly all of its production, while China uses most of its shrimp in the domestic market. The only other major export nation that has a strong domestic market for farmed shrimp is Mexico
.
Disease problems have repeatedly impacted the shrimp production negatively. Besides the near-wipeout of P. chinensis in 1993, there were outbreaks of viral diseases that led to marked declines in the per-country production in 1996/97 in Thailand and repeatedly in Ecuador. In Ecuador alone, production suffered heavily in 1989 (IHHN), 1993 (Taura), and 1999 (whitespot). Another reason for sometimes wild changes in shrimp farm output are the import regulations of the destination countries, which do not allow shrimp contaminated by chemicals or antibiotics to be imported.
In the 1980s and through much of the 1990s, shrimp farming promised high profits. The investments required for extensive farms were low, especially in regions with low land prices and wages. For many tropical countries, especially those with poorer economies, shrimp farming was an attractive business, offering jobs and incomes for poor coastal populations and has, due to the high market prices of shrimp, provided many developing countries with non-negligible foreign currency earnings. Many shrimp farms were funded initially by the World Bank
or substantially subsidized by local governments.
In the late 1990s, the economic situation changed. Governments and farmers alike were under increasing pressure from NGOs and the consumer countries, who criticized the practices of the trade. International trade
conflicts erupted, such as import bans by consumer countries on shrimp containing antibiotics, the United States
' shrimp import ban against Thailand in 2004 as a measure against Thai shrimp fishers not using turtle excluder device
s in their nets, or the "anti-dumping
" case initiated by U.S. shrimp fishers in 2002 against shrimp farmers worldwide, which resulted two years later in the U.S. imposing antidumping tariff
s of the order of about 10% against many producer countries (except China, which received a 112% duty). Diseases caused significant economic losses. In Ecuador
, where shrimp farming was a major export sector (the other two are banana
s and oil
), the whitespot outbreak of 1999 caused an estimated 130,000 workers to lose their jobs. Furthermore, shrimp prices dropped sharply in 2000. All of these factors contributed to the slowly growing acceptance by farmers that improved farming practices were needed, and resulted in tighter government regulation of the business, both of which internalized some of the external costs that were ignored during the boom years.
, with much regional variation and depending on the type of farms surveyed. In general, intensive shrimp farming requires more labor per unit area than extensive farming. Extensive shrimp farms cover much more land area and are often, but not always, located in areas where no agricultural land uses are possible. Supporting industries such as feed production or storage, handling, and trade companies should also not be neglected, even if not all of them are exclusive to shrimp farming.
Typically, workers on a shrimp farm can get better wages than with other employment. A global estimate from one study is that a shrimp farm worker can earn 1.5 – 3 times as much as in other jobs; a study from India arrived at a salary increase of about 1.6, and a report from Mexico states the lowest paid job at shrimp farms was paid in 1996 at 1.22 times the average worker salary in the country.
NGOs have frequently criticized that most of the profits went to large conglomerates instead of to the local population. While this may be true in certain regions, such as Ecuador
, where most shrimp farms are owned by large companies, it does not apply in all cases. For instance in Thailand, most farms are owned by small local entrepreneurs, although there is a trend to vertically integrate
the industries related to shrimp farming from feed producers to food processors and trade companies. A 1994 study reported a farmer in Thailand could increase his income by a factor of ten by switching from growing rice to farming shrimp. An Indian study from 2003 arrives at similar figures for shrimp farming in the East Godavari
district in Andhra Pradesh
.
Whether the local population benefits from shrimp farming is also dependent on the availability of sufficiently trained people. Extensive farms tend to offer mainly seasonal jobs during harvest that do not require much training. In Ecuador, many of these positions are known to have been filled by migrant workers. More intensive farms have a need for year-round labor in more sophisticated jobs.
s were cleared, reducing biodiversity
. During the 1980s and 1990s, about 35% of the world's mangrove forests had vanished. Shrimp farming was a major cause of this, accounting for over a third of it according to one study; other studies report between 5% and 10% globally, with enormous regional variability. Other causes of mangrove destruction are population pressure, logging, pollution from other industries, or conversion to other uses such as salt pans. Mangroves, through their roots, help stabilize a coastline and capture sediments; their removal has led to a marked increase of erosion
and less protection against floods. Mangrove estuaries are also especially rich and productive ecosystems and provide the spawning grounds for many species of fish, including many commercially important ones. Many countries have protected their mangroves and forbidden the construction of new shrimp farms in tidal or mangrove areas. The enforcement of the respective laws is often problematic, though, and especially in the least developed countries such as Bangladesh, Myanmar
, or Vietnam the conversion of mangroves to shrimp farms remains an issue for areas such as the Myanmar Coast mangroves
.
Intensive farms, while reducing the direct impact on the mangroves, have other problems. Their nutrient-rich effluents (industrial shrimp feeds disintegrate quickly, as little as 30% are actually eaten by the shrimp with a corresponding economic loss to the farmer, the rest is wasted) are typically discharged into the environment, seriously upsetting the ecological balance. These waste waters contain significant amounts of chemical fertilizer
s, pesticide
s, and antibiotic
s that cause pollution
of the environment. Furthermore, releasing antibiotics in such ways injects them into the food chain
and increases the risks of bacteria becoming resistant
against them. However, most aquatic bacteria, unlike bacteria associated with terrestrial animals, are not zoonotic. Only a few disease transfers from animals to humans have been reported.
Prolonged use of a pond can lead to an incremental buildup of a sludge at the pond's bottom from waste products and excrement. The sludge can be removed mechanically, or dried and plowed to allow biodecomposition, at least in areas without acid problems. Flushing a pond never completely removes this sludge, and eventually, the pond is abandoned, leaving behind a wasteland, with the soil made unusable for any other purposes due to the high levels of salinity, acidity, and toxic chemicals. A typical pond in an extensive farm can be used only a few years. An Indian study estimated the time to rehabilitate such lands to about 30 years. Thailand
has banned inland shrimp farms since 1999 because they caused too much destruction of agricultural lands due to salination
. A Thai study estimated 60% of the shrimp farming area in Thailand was abandoned in the years 1989–1996. Many of these problems stem from using mangrove land that has high natural pyrite
content (acid sulfate soil
) and poor drainage. The shift to semi-intensive farming requires higher elevations for drain harvesting and low sulfide
(pyrite) content to prevent acid formation when the soils shift from anaerobic
to aerobic conditions.
The global nature of the shrimp farming business, and in particular the shipment of broodstock
and hatchery products, throughout the world have not only introduced various shrimp species as exotic species, but also distributed the diseases the shrimp may carry worldwide. As a consequence, most broodstock shipments require health certificates and/or to have specific pathogen free (SPF) status. Many organizations lobby actively for consumers to avoid buying farmed shrimp; some also advocate the development of more sustainable
farming methods. A joint programme of the World Bank
, the Network of Aquaculture Centres in Asia-Pacific (NACA), the WWF
, and the FAO
was established in August 1999 to study and propose improved practices for shrimp farming. Some existing attempts at sustainable export-oriented shrimp farming marketing the shrimp as "ecologically produced" are criticized by NGOs as being dishonest and trivial window-dressing.
Yet, the industry has been slowly changing since about 1999. It has adopted the "best management practices" developed by the World Bank program, for example, and others. and instituted educational programs to promote them. Due to the mangrove protection laws enacted in many countries, new farms are usually of the semi-intensive kind, which are best constructed outside mangrove areas anyway. There is a trend to create even more tightly controlled environments in these farms, with the hope to achieve better disease prevention. Waste water treatment has attracted considerable attention; modern shrimp farms routinely have effluent treatment ponds where sediments are allowed to settle at the bottom and other residuals are filtered. As such improvements are costly, the World Bank program also recommends low-intensity polyculture
farming for some areas. Since it has been discovered that mangrove soils are effective in filtering waste waters and tolerate high nitrate
levels, the industry has also developed an interest in mangrove reforestation
, although its contributions in that area are still minor. The long-term effects of these recommendations and industry trends cannot be evaluated conclusively yet.
A significant problem causing much conflict in some regions, for instance in Bangladesh
, are the land use rights. With shrimp farming, a new industry expanded into coastal areas and started to make exclusive use of previously public resources. In some areas, the rapid expansion resulted in the local coastal population being denied access to the coast by a continuous strip of shrimp farms with serious impacts on the local fisheries. Such problems were compounded by poor ecological practices that caused a degradation of common resources (such as excessive use of freshwater
to control the salinity of the ponds, causing the water table
to sink and leading to the salination of freshwater aquifer
s by an inflow of salt water). With growing experience, countries usually introduced stronger governmental regulations and have taken steps to mitigate such problems, for instance through land zoning
legislations. Some late adopters have even managed to avoid some problems through proactive legislation, e.g. Mexico. The situation in Mexico is unique owing to the strongly government-regulated market. Even after the liberalisation in the early 1990s, most shrimp farms are still owned and controlled by locals or local co-ops (ejido
s).
Social tensions have occurred due to changes in the wealth distribution within populations. The effects of this are mixed, though, and the problems are not unique to shrimp farming. Changes in the distribution of wealth tend to induce changes in the power structure within a community. In some cases, there is a widening gap between the general population and local élites who have easier access to credits, subsidies, and permits and thus are more likely to become shrimp farmers and benefit more. In Bangladesh, on the other hand, local élites were opposing shrimp farming, which was controlled largely by an urban élite. Land concentrations in a few hands has been recognized to carry an increased risk of social and economic problems developing, especially if the landowners are non-local.
In general, it has been found that shrimp farming is accepted best and introduced most easily and with the greatest benefits for the local communities if the farms are owned by local people instead of by restricted remote élites or large companies because local owners have a direct interest in maintaining the environment and good relations with their neighbors, and because it avoids the formation of large-scale land property.
" and "prawn
" is often blurred. The FAO, for instance, calls P. monodon the "Giant Tiger Prawn", but P. vannamei the "Whiteleg Shrimp". Recent aquaculture literature increasingly uses the term "prawn" only for the freshwater forms of palaemonids and "shrimp" for the marine penaeids.
Since adult shrimp are bottom dwellers, stocking densities in ponds are usually given per area, not per water volume.
The taxonomy
of the whole genus
Penaeus is in flux. Pérez Farfante and Kensley have proposed a subdivision or reassignment of several species in this genus to new genera based on morphological differences, in particular their genital characteristics. See Penaeus
for more information. As a consequence, some of the farmed species are also known under names using the genera Litopenaeus, Farfantepenaeus, Fenneropenaeus, or Marsupenaeus instead of plain Penaeus. Penaeus vannamei, for instance, has become Litopenaeus vannamei.
Accurate statistics on shrimp farming do not exist. The FAO
relies on the voluntary reporting of countries for its fisheries databases; if no numbers are reported, the FAO fills in its own "guesstimate". Such estimates are marked in the databases, but these obviously also contain estimates made already by the reporting government agencies, recognizable only by the suspiciously round numbers.
Aquaculture
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...
business for the cultivation of marine shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
or prawn
Prawn
Prawns are decapod crustaceans of the sub-order Dendrobranchiata. There are 540 extant species, in seven families, and a fossil record extending back to the Devonian...
s for human consumption. Commercial shrimp farming began in the 1970s, and production grew steeply, particularly to match the market demands of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
and Western Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
. The total global production of farmed shrimp reached more than 1.6 million tonne
Tonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
s in 2003, representing a value of nearly 9 billion U.S. dollars
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
. About 75% of farmed shrimp is produced in Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, in particular in China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...
and Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
. The other 25% is produced mainly in Latin America
Latin America
Latin America is a region of the Americas where Romance languages – particularly Spanish and Portuguese, and variably French – are primarily spoken. Latin America has an area of approximately 21,069,500 km² , almost 3.9% of the Earth's surface or 14.1% of its land surface area...
, where Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
are the largest producers. The largest exporting nation is Thailand.
Shrimp farming has changed from traditional, small-scale businesses in Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
into a global industry. Technological advances have led to growing shrimp at ever higher densities, and broodstock
Broodstock
Broodstock, or broodfish, are a group of mature individuals used in aquaculture for breeding purposes. Broodstock can be a population of animals maintained in captivity as a source of replacement for, or enhancement of, seed and fry numbers. These are generally kept in ponds or tanks in which...
is shipped worldwide. Virtually all farmed shrimp are of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Penaeidae
Penaeidae
Penaeidae is a family of prawns, although they are often referred to as penaeid shrimp. It contains many species of economic importance, such as the tiger prawn , whiteleg shrimp, Atlantic white shrimp and Indian prawn. Many prawns are the subject of commercial fishery, and farming, both in marine...
, and just two species – Penaeus vannamei
Whiteleg shrimp
Whiteleg shrimp , also known as Pacific white shrimp, is a variety of prawn of the eastern Pacific Ocean commonly caught or farmed for food.-Description:...
(Pacific white shrimp) and Penaeus monodon
Penaeus monodon
Penaeus monodon, the giant tiger prawn , is a marine crustacean that is widely reared for food.-Distribution:...
(giant tiger prawn) – account for roughly 80% of all farmed shrimp. These industrial monoculture
Monoculture
Monoculture is the agricultural practice of producing or growing one single crop over a wide area. It is also known as a way of farming practice of growing large stands of a single species. It is widely used in modern industrial agriculture and its implementation has allowed for large harvests from...
s are very susceptible to diseases, which have caused several regional wipe-outs of farm shrimp populations. Increasing ecological problems, repeated disease outbreaks, and pressure and criticism from both NGOs
Non-governmental organization
A non-governmental organization is a legally constituted organization created by natural or legal persons that operates independently from any government. The term originated from the United Nations , and is normally used to refer to organizations that do not form part of the government and are...
and consumer countries led to changes in the industry in the late 1990s and generally stronger regulation by governments. In 1999, a program aimed at developing and promoting more sustainable farming
Sustainable agriculture
Sustainable agriculture is the practice of farming using principles of ecology, the study of relationships between organisms and their environment...
practices was initiated, including governmental bodies, industry representatives, and environmental organizations.
History and geography
Indonesians and others have farmed shrimp for centuries, using traditional low-density methods. IndonesiaIndonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
n brackish water
Brackish water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
ponds, called tambaks, can be traced back as far as the 15th century. They used small scale ponds for monoculture
Monoculture
Monoculture is the agricultural practice of producing or growing one single crop over a wide area. It is also known as a way of farming practice of growing large stands of a single species. It is widely used in modern industrial agriculture and its implementation has allowed for large harvests from...
or polyculture
Polyculture
Polyculture is agriculture using multiple crops in the same space, in imitation of the diversity of natural ecosystems, and avoiding large stands of single crops, or monoculture...
d with other species, such as milkfish
Milkfish
The milkfish is the sole living species in the family Chanidae. - Description and biology :...
, or in rotation with rice
Rice
Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
, using the rice paddies
Paddy field
A paddy field is a flooded parcel of arable land used for growing rice and other semiaquatic crops. Paddy fields are a typical feature of rice farming in east, south and southeast Asia. Paddies can be built into steep hillsides as terraces and adjacent to depressed or steeply sloped features such...
for shrimp cultures during the dry season, when no rice could be grown. Such cultures often were in coastal areas or on river banks. Mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
areas were favored because of their abundant natural shrimp. Wild juvenile shrimp were trapped in ponds and reared on naturally occurring organisms in the water until they reached the desired size for harvesting.
Industrial shrimp farming can be traced to the 1930s, when Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese agrarians spawned and cultivated Kuruma shrimp (Penaeus japonicus) for the first time. By the 1960s, a small industry had developed in Japan. Commercial shrimp farming began to grow rapidly in the late 1960s and early 1970s. Technological advances led to more intensive forms of farming, and growing market demand led to worldwide proliferation of shrimp farms, concentrated in tropical and subtropical regions. Growing consumer demand in the early 1980s coincided with faltering wild catches, creating a booming industry. Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
was an early adopter and a major producer in the 1980s; its production collapsed beginning in 1988 due to poor management practices and disease. In Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, large-scale production expanded rapidly from 1985. In South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
pioneered shrimp farming, where it expanded dramatically from 1978. Brazil had been active in shrimp farming since 1974, but trade boomed there only in the 1990s, making the country a major producer within a few years. Today, there are marine shrimp farms in over fifty countries.
Farming methods
When shrimp farming emerged to satisfy demand that had surpassed the wild fisheries' capacity, the subsistence farming methods of old were rapidly replaced by the more productive practices required to serve a global market. Industrial farming at first followed traditional methods, with so-called "extensive" farms, compensating for low density with increased pond sizes; instead of ponds of just a few hectareHectare
The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
s, ponds of sizes up to 100 hectare were used and huge areas of mangroves were cleared in some areas. Technological advances made more intensive practices possible that increase yield per area, helping reduce pressure to convert more land. Semi-intensive and intensive farms appeared, where the shrimp were reared on artificial feeds and ponds were actively managed. Although many extensive farms remain, new farms typically are of the semi-intensive kind.
Until the mid-1980s, most farms were stocked with young wild animals, called 'postlarvae', typically caught locally. Postlarvae fishing became an important economic sector in many countries. To counteract the depletion of fishing grounds and to ensure a steady supply of young shrimp, the industry started breeding shrimp in hatcheries
Hatchery
A hatchery is a facility where eggs are hatched under artificial conditions, especially those of fish or poultry. It may be used for ex-situ conservation purposes, i.e. to breed rare or endangered species under controlled conditions; alternatively, it may be for economic reasons A hatchery is a...
.
Life cycle
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
. The females lay 50,000 to 1 million eggs, which hatch after some 24 hours into tiny nauplii. These nauplii feed on yolk reserves within their bodies, and then metamorphose into zoeae. Shrimp in this second larval stage feed in the wild on algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
, and after a few days, morph again into myses. The myses look akin to tiny shrimp, and feed on algae and zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
. After another three to four days, they metamorphose a final time into postlarvae: young shrimp that have adult characteristics. The whole process takes about 12 days from hatching. In the wild, postlarvae then migrate into estuaries
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
, which are rich in nutrients and low in salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
. They migrate back into open waters when they mature. Adult shrimp are benthic animals living primarily on the sea bottom.
Supply chain
In shrimp farming, this lifecycle occurs under controlled conditions. The reasons to do so include more intensive farming, improved size control resulting in more uniformly sized shrimp, and better predator control, but also the ability to accelerate growth and maturation by controlling the climate (especially in farms in the temperate zones, using greenhouseGreenhouse
A greenhouse is a building in which plants are grown. These structures range in size from small sheds to very large buildings...
s). There are three different stages:
- Hatcheries breed shrimp and produce nauplii or even postlarvae, which they sell to farms. Large shrimp farms maintain their own hatcheries and sell nauplii or postlarvae to smaller farms in the region.
- Nurseries grow postlarvae and accustom them to the marine conditions in the growout ponds.
- In the growout ponds the shrimp are grown from juveniles to marketable size, which takes between three to six months.
Most farms produce one to two harvests a year; in tropical climates, even three are possible. Because of the need for salt water, shrimp farms are located on or near a coast. Inland shrimp farms have also been tried in some regions, but the need to ship salt water and competition for land with agricultural users led to problems. Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
banned inland shrimp farms in 1999.
Hatcheries
Greenwater hatcheries are medium-sized hatcheries using large tanks with low animal densities. To feed the shrimp larvae, an algal bloom
Algal bloom
An algal bloom is a rapid increase or accumulation in the population of algae in an aquatic system. Algal blooms may occur in freshwater as well as marine environments. Typically, only one or a small number of phytoplankton species are involved, and some blooms may be recognized by discoloration...
is induced in the tanks. The survival rate is about 40%.
Galveston hatcheries (named after Galveston, Texas
Galveston, Texas
Galveston is a coastal city located on Galveston Island in the U.S. state of Texas. , the city had a total population of 47,743 within an area of...
, where they were developed) are large-scale, industrial hatcheries using a closed and tightly controlled environment. They breed the shrimp at high densities in large (15 to 30 ton) tanks. Survival rates vary between zero and 80%, but typically achieve 50%.
In hatcheries, the developing shrimp are fed on a diet of algae and later also brine shrimp
Brine shrimp
Artemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period...
nauplii, sometimes (especially in industrial hatcheries) augmented by artificial diets. The diet of later stages also includes fresh or freeze-dried animal protein, for example krill
Krill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...
. Nutrition and medication (such as antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s) fed to the brine shrimp nauplii are passed on to the shrimp that eat them.
Nurseries
Many farms have nurseries where the postlarval shrimp are grown into juveniles for another three weeks in separate ponds, tanks, or so-called raceways. A raceway is a rectangular, long, shallow tank through which water flows continuously.In a typical nursery, there are 150 to 200 animals per square metre. They are fed on a high-protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
diet for at most three weeks before they are moved to the growout ponds. At that time, they weigh between one and two grams. The water salinity is adjusted gradually to that of the growout ponds.
Farmers refer to postlarvae as "PLs", with the number of days suffixed (i.e., PL-1, PL-2, etc.). They are ready to be transferred to the growout ponds after their gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
s have branched, which occurs around PL-13 to PL-17 (about 25 days after hatching). Nursing is not absolutely necessary, but is favoured by many farms because it makes for better food utilization, improves the size uniformity, helps use the infrastructure better, and can be done in a controlled environment to increase the harvest. The main disadvantage of nurseries is that some of the postlarval shrimp die upon the transfer to the growout pond.
Some farms do not use a nursery, but stock the postlarvae directly in the growout ponds after having acclimated them to the appropriate temperature and salinity levels in an acclimation tank. Over the course of a few days, the water in these tanks is changed gradually to match that of the growout ponds. The animal density should not exceed 500/litre for young postlarvae and 50/liter for larger ones, such as PL-15.
Growout
In the growout phase, the shrimp are grown to maturity. The postlarvae are transferred to ponds where they are fed until they reach marketable size, which takes about another three to six months. Harvesting the shrimp is done by fishing them from the ponds using nets or by draining the ponds. Pond sizes and the level of technical infrastructure vary.Extensive shrimp farms using traditional low-density methods are invariably located on a coast and often in mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
areas. The ponds range from just a few to more than 100 hectare
Hectare
The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
s; shrimp are stocked at low densities (2–3 animals per square metre, or 25,000/ha). The tides provide for some water exchange, and the shrimp feed on naturally occurring organisms. In some areas, farmers even grow wild shrimp by just opening the gates and impounding wild larvae. Prevalent in poorer or less developed countries where land prices are low, extensive farms produce annual yields from 50 to 500 kg/ha of shrimp (head-on weight). They have low production costs (US$1–3/kg live shrimp), are not very labor intensive, and do not require advanced technical skills.
Semi-intensive farms do not rely on tide
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the moon and the sun and the rotation of the Earth....
s for water exchange, but use pumps and a planned pond layout. They can therefore be built above the high tide line. Pond sizes range from 2 to 30 ha; the stocking densities range from 10 to 30/square meter (100,000–300,000/ha). At such densities, artificial feeding using industrially prepared shrimp feeds and fertilizing the pond to stimulate the growth of naturally occurring organisms become a necessity. Annual yields range from 500 to 5,000 kg/ha, while production costs are in the range of US$2–6/kg live shrimp. With densities above 15 animals per square meter, aeration
Aeration
Aeration is the process by which air is circulated through, mixed with or dissolved in a liquid or substance.-Aeration of liquids:-Methods:Aeration of liquids is achieved by:...
is often required to prevent oxygen depletion. Productivity varies depending upon water temperature, thus it is common to have larger sized shrimp in some seasons than in others.
Intensive farms use even smaller ponds (0.1–1.5 ha) and even higher stocking densities. The ponds are actively managed: they are aerated, there is a high water exchange to remove waste products and maintain water quality, and the shrimp are fed on specially designed diets, typically in the form of formulated pellets. Such farms produce annual yields between 5,000 and 20,000 kg/ha; a few super-intensive farms can produce as much as 100,000 kg/ha. They require an advanced technical infrastructure and highly trained professionals for constant monitoring of water quality and other pond conditions; their production costs are in the range of US$4–8/kg live shrimp.
Estimates on the production characteristics of shrimp farms vary. Most studies agree that about 55–60% of all shrimp farms worldwide are extensive farms, another 25–30% are semi-intensive, and the rest are intensive farms. Regional variation is high, though, and [Tacon (2002)] reports wide discrepancies in the percentages claimed for individual countries by different studies.
Feeding the shrimp
While extensive farms mainly rely on the natural productivity of the ponds, more intensively managed farms rely on artificial shrimp feeds, either exclusively or as a supplement to the organisms that naturally occur in a pond. A food chainFood chain
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...
is established in the ponds, based on the growth of phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
. Fertilizers and mineral conditioners are used to boost the growth of the phytoplankton to accelerate the growth of the shrimp. Waste from the artificial food pellets and shrimp excrement can lead to the eutrophication
Eutrophication
Eutrophication or more precisely hypertrophication, is the movement of a body of water′s trophic status in the direction of increasing plant biomass, by the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system...
of the ponds.
Artificial feeds come in the form of specially formulated, granulated pellets that disintegrate quickly. Up to 70% of such pellets are wasted, as they decay before the shrimp have eaten them. They are fed two to five times daily; the feeding can be done manually either from ashore or from boats, or using mechanized feeders distributed all over a pond. The feed conversion rate (FCR), i.e. the amount of food needed to produce a unit (e.g. one kilogram) of shrimp, is claimed by the industry to be around 1.2–2.0 in modern farms, but this is an optimum value that is not always attained in practice. For a farm to be profitable, a feed conversion rate below 2.5 is necessary; in older farms or under suboptimal pond conditions, the ratio may easily rise to 4:1. Lower FCRs result in a higher profit for the farm.
Farmed species
Although there are many species of shrimp and prawn, only a few of the larger ones are actually cultivated, all of which belong to the family of penaeids (familyFamily (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Penaeidae
Penaeidae
Penaeidae is a family of prawns, although they are often referred to as penaeid shrimp. It contains many species of economic importance, such as the tiger prawn , whiteleg shrimp, Atlantic white shrimp and Indian prawn. Many prawns are the subject of commercial fishery, and farming, both in marine...
), and within it to the genus Penaeus
Penaeus
Penaeus is a genus of prawns, including the giant tiger prawn , the most important species of farmed crustacean worldwide. The genus has been reorganised following a proposition of Pérez Farfante and Kensley based on morphological differences, in particular the genital characteristics of these...
. Many species are unsuitable for farming: they are too small to be profitable, or simply stop growing when crowded together, or are too susceptible to diseases. The two species dominating the market are:
- Pacific white shrimp (Litopenaeus vannamei, also called "whiteleg shrimp") is the main species cultivated in western countries. Native to the PacificPacific OceanThe Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
coast from MexicoMexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
to PeruPeruPeru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, it grows to a size of 23 cm. L. vannamei accounts for 95% of the production in Latin AmericaLatin AmericaLatin America is a region of the Americas where Romance languages – particularly Spanish and Portuguese, and variably French – are primarily spoken. Latin America has an area of approximately 21,069,500 km² , almost 3.9% of the Earth's surface or 14.1% of its land surface area...
. It is easy to breed in captivity, but succumbs to the Taura disease. - Giant tiger prawn (P. monodon, also known as "black tiger shrimp") occurs in the wild in the Indian OceanIndian OceanThe Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
and in the Pacific OceanPacific OceanThe Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
from Japan to AustraliaAustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. The largest of all the cultivated shrimp, it can grow to a length of 36 cm and is farmed in AsiaAsiaAsia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
. Because of its susceptibility to whitespot disease and the difficulty of breeding it in captivity, it is gradually being replaced by L. vannamei since 2001.
Together, these two species account for about 80% of the whole farmed shrimp production. Other species being bred are:
- Western blue shrimp (P. stylirostris) was a popular choice for shrimp farming in the western hemisphere, until the IHHN virus wiped out nearly the whole population in the late 1980s. A few stocks survived and became resistant against this virus. When it was discovered that some of these were also resistant against the Taura virus, some farms again bred P. stylirostris from 1997 on.
- Chinese white shrimp (P. chinensis, also known as the fleshy prawn) occurs along the coast of ChinaPeople's Republic of ChinaChina , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...
and the western coast of KoreaKoreaKorea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
and is being farmed in China. It grows to a maximum length of only 18 cm, but tolerates colder water (min. 16 °C). Once a major factor on the world market, it is today used almost exclusively for the Chinese domestic market after a disease wiped out nearly all the stocks in 1993. - Kuruma shrimp (P. japonicus) is farmed primarily in Japan and TaiwanTaiwanTaiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, but also in Australia; the only market is in Japan, where live Kuruma shrimp reach prices of the order of US$100 per poundPound (mass)The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...
($220/kg). - Indian white shrimpIndian prawnThe Indian prawn, Fenneropenaeus indicus , is one of the major commercial prawn species of the world. It is found in the Indo-West Pacific from eastern and south-eastern Africa, through India, Malaysia and Indonesia to southern China and northern Australia.-Common names:F...
(P. indicus) is a native of the coasts of the Indian OceanIndian OceanThe Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
and is widely bred in IndiaIndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, IranIranIran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
and the Middle EastMiddle EastThe Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
and along the African shores. - Banana shrimp (P. merguiensis) is another cultured species from the coastal waters of the Indian Ocean, from OmanOmanOman , officially called the Sultanate of Oman , is an Arab state in southwest Asia on the southeast coast of the Arabian Peninsula. It is bordered by the United Arab Emirates to the northwest, Saudi Arabia to the west, and Yemen to the southwest. The coast is formed by the Arabian Sea on the...
to IndonesiaIndonesiaIndonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
and AustraliaAustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. It can be grown at high densities.
Several other species of Penaeus play only a very minor role in shrimp farming. Some other kinds of shrimp also can be farmed, e.g. the "Akiami paste shrimp" or Metapenaeus spp. Their total production from aquaculture is of the order of only about 25,000 tonnes per year, small in comparison to that of the penaeids.
Diseases
There are a variety of lethal viralVirus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
s that affect shrimp. In the densely populated, monocultural
Monoculture
Monoculture is the agricultural practice of producing or growing one single crop over a wide area. It is also known as a way of farming practice of growing large stands of a single species. It is widely used in modern industrial agriculture and its implementation has allowed for large harvests from...
farms such virus infections spread rapidly and may wipe out whole shrimp populations. A major transfer vector of many of these viruses is the water itself; and thus any virus outbreak also carries the danger of decimating shrimp living in the wild.
Yellowhead disease
Yellowhead disease
Yellowhead disease is a viral infection of shrimp and prawn, in particular of the giant tiger prawn , one of the two major species of farmed shrimp. The disease is highly lethal and contagious, killing shrimp quickly. Outbreaks of this disease have wiped out in a matter of days the entire...
, called Hua leung in Thai
Thai language
Thai , also known as Central Thai and Siamese, is the national and official language of Thailand and the native language of the Thai people, Thailand's dominant ethnic group. Thai is a member of the Tai group of the Tai–Kadai language family. Historical linguists have been unable to definitively...
, affects P. monodon throughout Southeast Asia. It had been reported first in Thailand in 1990. The disease is highly contagious and leads to mass mortality within 2 to 4 days. The cephalothorax
Cephalothorax
The cephalothorax is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. The word cephalothorax is derived from the Greek words for head and thorax...
of an infected shrimp turns yellow after a period of unusually high feeding activity ending abruptly, and the then moribund shrimp congregate near the surface of their pond before dying.
Whitespot syndrome is a disease caused by a family of related viruses. First reported in 1993 from Japanese P. japonicus cultures, it spread throughout Asia and then to the Americas. It has a wide host range and is highly lethal, leading to mortality rates of 100% within days. Symptoms include white spots on the carapace and a red hepatopancreas
Hepatopancreas
The hepatopancreas, digestive gland or midgut gland is an organ of the digestive tract of arthropods, molluscs and fish. It provides the functions which in mammals are provided separately by the liver and pancreas, including the production of digestive enzymes, and absorption of digested...
. Infected shrimp become lethargic before they die.
Taura syndrome
Taura syndrome
Taura syndrome is one of the more devastating diseases affecting the shrimp farming industry worldwide.Taura syndrome was first described in Ecuador during the summer of 1992. In March 1993, it returned as a major epidemic and was the object of extensive media coverage...
was first reported from shrimp farms on the Taura river in Ecuador in 1992. The host of the virus causing the disease is P. vannamei, one of the two most commonly farmed shrimp. The disease spread rapidly, mainly through the shipping of infected animals and broodstock. Originally confined to farms in the Americas, it has also been propagated to Asian shrimp farms with the introduction of L. vannamei there. Birds are thought to be a route of infection between farms within one region.
Infectious hypodermal and hematopoietic necrosis
Infectious Hypodermal and Hematopoietic Necrosis
Infectious hypodermal and hematopoietic necrosis is a viral disease of penaeid shrimp that causes mass mortality among the Western blue shrimp and severe deformations in the Pacific white shrimp . It occurs in Pacific farmed and wild shrimp, but not in wild shrimp on the Atlantic coast of the...
(IHHN) is a disease that causes mass mortality among P. stylirostris (as high as 90%) and severe deformations in L. vannamei. It occurs in Pacific farmed and wild shrimp, but not in wild shrimp on the Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
coast of the Americas.
There are also a number of bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
l infections that are lethal to shrimp. The most common is vibriosis, caused by bacteria of the Vibrio
Vibrio
Vibrio is a genus of Gram-negative bacteria possessing a curved rod shape, several species of which can cause foodborne infection, usually associated with eating undercooked seafood. Typically found in saltwater, Vibrio are facultative anaerobes that test positive for oxidase and do not form...
species. The shrimp become weak and disoriented, and may have dark wounds on the cuticle
Cuticle
A cuticle , or cuticula, is a term used for any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticles" are non-homologous; differing in their origin, structure, function, and chemical composition...
. The mortality rate can exceed 70%. Another bacterial disease is necrotising hepatopancreatitis
Necrotising hepatopancreatitis
Necrotising hepatopancreatitis , also known as the Texas pond mortality syndrome , Texas necrotizing hepatopancreatitis and Peru necrotizing hepatopancreatitis , is a lethal epizootic disease of farmed shrimp, caused by a bacterial infection.NHP mainly affects the farmed shrimp species Litopenaeus...
(NHP); symptoms include a soft exoskeleton and fouling. Most such bacterial infections are strongly correlated to stressful conditions, such as overcrowded ponds, high temperatures, and poor water quality, factors that positively influence the growth of bacteria. Treatment is done using antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s. Importing countries have repeatedly placed import bans on shrimp containing various antibiotics. One such antibiotic is chloramphenicol
Chloramphenicol
Chloramphenicol is a bacteriostatic antimicrobial that became available in 1949. It is considered a prototypical broad-spectrum antibiotic, alongside the tetracyclines, and as it is both cheap and easy to manufacture it is frequently found as a drug of choice in the third world.Chloramphenicol is...
, which has been banned in the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
since 1994, but continues to pose problems.
With their high mortality rates, diseases represent a very real danger to shrimp farmers, who may lose their income for the whole year if their ponds are infected. Since most diseases cannot yet be treated effectively, the industry's efforts are focused on preventing disease outbreak in the first place. Active water quality management helps avoid poor pond conditions favorable to the spread of diseases, and instead of using larvae from wild catches, specific pathogen free
Specific Pathogen Free
Specific Pathogen Free is a term used for laboratory animals that are guaranteed free of particular pathogens. It is always accompanied by a list of the absent pathogens.Use of SPF animals ensures that specified diseases do not interfere with an experiment...
broodstock
Broodstock
Broodstock, or broodfish, are a group of mature individuals used in aquaculture for breeding purposes. Broodstock can be a population of animals maintained in captivity as a source of replacement for, or enhancement of, seed and fry numbers. These are generally kept in ponds or tanks in which...
s raised in captivity in isolated environments and certified not to carry diseases are used increasingly. To avoid introducing diseases into such disease-free populations on a farm, there is also a trend to create more controlled environments in the ponds of semi-intensive farms, such as by lining them with plastic to avoid soil contact, and by minimizing water exchange in the ponds.
Economy
The total global production of farmed shrimp reached 2.5 million tonneTonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
s in 2005. This accounts for 42% of the total shrimp production that year (farming and wild catches combined). The largest single market for shrimp is the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, importing between 500 – 600,000 tonnes of shrimp products yearly in the years 2003-2009. About 200,000 tonnes yearly are imported by Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, while the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
imported in 2006 another about 500,000 tonnes of tropical shrimps, with the largest importers being Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
and France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
. The EU also is a major importer of coldwater shrimp from catches, mainly common shrimp (Crangon crangon
Crangon crangon
Crangon crangon is a commercially important species of shrimp fished mainly in the southern North Sea, although also found in the Irish Sea, Baltic Sea, Mediterranean Sea and Black Sea, as well as off much of Scandinavia and parts of Morocco's Atlantic coast...
) and Pandalidae
Pandalidae
The family Pandalidae is a taxon of Caridean shrimp. These species are commonly called pandalid shrimps. They are edible and have high economic value. They are characterized by the subdivided carpus of the second pereiopod and, mainly, by the lack of the chelae of the first pereiopod...
such as Pandalus borealis
Pandalus borealis
Pandalus borealis is a species of shrimp found in cold parts of the Atlantic and Pacific Oceans. Many different common names are used, including pink shrimp, deepwater prawn, deep-sea prawn, great northern prawn, and northern shrimp.-Distribution:P...
; in 2006, these imports accounted for about another 200,000 tonnes.
The import prices for shrimp fluctuate wildly. In 2003, the import price per kilogram
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...
shrimp in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
was US$ 8.80, slightly higher than in Japan at US$8.00. The average import price in the EU was only about US$5.00/kg; this much lower value is explained by the fact that the EU imports more coldwater shrimp (from catches) that are much smaller than the farmed warm water species, and thus attain lower prices. In addition, Mediterranean Europe prefers head-on shrimp, which weigh approximately 30% more, but have a lower unit price.
About 75% of the world production of farmed shrimp comes from Asian countries; the two leading nations being China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...
and Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, closely followed by Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
, Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, and India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
. The other 25% are produced in the western hemisphere, where Latin American countries (Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
) dominate. In terms of export, Thailand is by far the leading nation, with a market share of more than 30%, followed by China, Indonesia, and India, accounting each for about 10%. Other major export nations are Vietnam, Bangladesh, and Ecuador. Thailand exports nearly all of its production, while China uses most of its shrimp in the domestic market. The only other major export nation that has a strong domestic market for farmed shrimp is Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
.
Disease problems have repeatedly impacted the shrimp production negatively. Besides the near-wipeout of P. chinensis in 1993, there were outbreaks of viral diseases that led to marked declines in the per-country production in 1996/97 in Thailand and repeatedly in Ecuador. In Ecuador alone, production suffered heavily in 1989 (IHHN), 1993 (Taura), and 1999 (whitespot). Another reason for sometimes wild changes in shrimp farm output are the import regulations of the destination countries, which do not allow shrimp contaminated by chemicals or antibiotics to be imported.
In the 1980s and through much of the 1990s, shrimp farming promised high profits. The investments required for extensive farms were low, especially in regions with low land prices and wages. For many tropical countries, especially those with poorer economies, shrimp farming was an attractive business, offering jobs and incomes for poor coastal populations and has, due to the high market prices of shrimp, provided many developing countries with non-negligible foreign currency earnings. Many shrimp farms were funded initially by the World Bank
World Bank
The World Bank is an international financial institution that provides loans to developing countries for capital programmes.The World Bank's official goal is the reduction of poverty...
or substantially subsidized by local governments.
In the late 1990s, the economic situation changed. Governments and farmers alike were under increasing pressure from NGOs and the consumer countries, who criticized the practices of the trade. International trade
International trade
International trade is the exchange of capital, goods, and services across international borders or territories. In most countries, such trade represents a significant share of gross domestic product...
conflicts erupted, such as import bans by consumer countries on shrimp containing antibiotics, the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
' shrimp import ban against Thailand in 2004 as a measure against Thai shrimp fishers not using turtle excluder device
Turtle excluder device
A turtle excluder device or TED is a specialized device that allows a captured sea turtle to escape when caught in a fisherman's net.In particular, sea turtles can be caught when bottom trawling is used by the commercial shrimp fishing industry. In order to catch shrimp, a fine meshed trawl net is...
s in their nets, or the "anti-dumping
Dumping (pricing policy)
In economics, "dumping" is any kind of predatory pricing, especially in the context of international trade. It occurs when manufacturers export a product to another country at a price either below the price charged in its home market, or in quantities that cannot be explained through normal market...
" case initiated by U.S. shrimp fishers in 2002 against shrimp farmers worldwide, which resulted two years later in the U.S. imposing antidumping tariff
Tariff
A tariff may be either tax on imports or exports , or a list or schedule of prices for such things as rail service, bus routes, and electrical usage ....
s of the order of about 10% against many producer countries (except China, which received a 112% duty). Diseases caused significant economic losses. In Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, where shrimp farming was a major export sector (the other two are banana
Banana
Banana is the common name for herbaceous plants of the genus Musa and for the fruit they produce. Bananas come in a variety of sizes and colors when ripe, including yellow, purple, and red....
s and oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
), the whitespot outbreak of 1999 caused an estimated 130,000 workers to lose their jobs. Furthermore, shrimp prices dropped sharply in 2000. All of these factors contributed to the slowly growing acceptance by farmers that improved farming practices were needed, and resulted in tighter government regulation of the business, both of which internalized some of the external costs that were ignored during the boom years.
Socioeconomic aspects
Shrimp farming offers significant employment opportunities, which may help alleviate the poverty of the local coastal populations in many areas, if it is properly managed. The published literature on that topic shows large discrepancies, and much of the available data are of anecdotal nature. Estimates of the labor intensity of shrimp farms range from about one-third to three times more than when the same area was used for rice paddiesPaddy field
A paddy field is a flooded parcel of arable land used for growing rice and other semiaquatic crops. Paddy fields are a typical feature of rice farming in east, south and southeast Asia. Paddies can be built into steep hillsides as terraces and adjacent to depressed or steeply sloped features such...
, with much regional variation and depending on the type of farms surveyed. In general, intensive shrimp farming requires more labor per unit area than extensive farming. Extensive shrimp farms cover much more land area and are often, but not always, located in areas where no agricultural land uses are possible. Supporting industries such as feed production or storage, handling, and trade companies should also not be neglected, even if not all of them are exclusive to shrimp farming.
Typically, workers on a shrimp farm can get better wages than with other employment. A global estimate from one study is that a shrimp farm worker can earn 1.5 – 3 times as much as in other jobs; a study from India arrived at a salary increase of about 1.6, and a report from Mexico states the lowest paid job at shrimp farms was paid in 1996 at 1.22 times the average worker salary in the country.
NGOs have frequently criticized that most of the profits went to large conglomerates instead of to the local population. While this may be true in certain regions, such as Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, where most shrimp farms are owned by large companies, it does not apply in all cases. For instance in Thailand, most farms are owned by small local entrepreneurs, although there is a trend to vertically integrate
Vertical integration
In microeconomics and management, the term vertical integration describes a style of management control. Vertically integrated companies in a supply chain are united through a common owner. Usually each member of the supply chain produces a different product or service, and the products combine to...
the industries related to shrimp farming from feed producers to food processors and trade companies. A 1994 study reported a farmer in Thailand could increase his income by a factor of ten by switching from growing rice to farming shrimp. An Indian study from 2003 arrives at similar figures for shrimp farming in the East Godavari
East Godavari
East Godavari District is a district situated on the northeast of the state of Andhra Pradesh in India. Its district headquarters is Kakinada. It is the second richest district in the whole country...
district in Andhra Pradesh
Andhra Pradesh
Andhra Pradesh , is one of the 28 states of India, situated on the southeastern coast of India. It is India's fourth largest state by area and fifth largest by population. Its capital and largest city by population is Hyderabad.The total GDP of Andhra Pradesh is $100 billion and is ranked third...
.
Whether the local population benefits from shrimp farming is also dependent on the availability of sufficiently trained people. Extensive farms tend to offer mainly seasonal jobs during harvest that do not require much training. In Ecuador, many of these positions are known to have been filled by migrant workers. More intensive farms have a need for year-round labor in more sophisticated jobs.
Marketing
For commercialization, shrimp are graded and marketed in different categories. From complete shrimp (known as "head-on, shell-on" or HOSO) to peeled and deveined (P&D), any presentation is available in stores. The animals are graded by their size uniformity and then also by their count per weight unit, with larger shrimp attaining higher prices.Ecological impacts
Shrimp farms of all types, from extensive to super-intensive, can cause severe ecological problems wherever they are located. For extensive farms, huge areas of mangroveMangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
s were cleared, reducing biodiversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
. During the 1980s and 1990s, about 35% of the world's mangrove forests had vanished. Shrimp farming was a major cause of this, accounting for over a third of it according to one study; other studies report between 5% and 10% globally, with enormous regional variability. Other causes of mangrove destruction are population pressure, logging, pollution from other industries, or conversion to other uses such as salt pans. Mangroves, through their roots, help stabilize a coastline and capture sediments; their removal has led to a marked increase of erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
and less protection against floods. Mangrove estuaries are also especially rich and productive ecosystems and provide the spawning grounds for many species of fish, including many commercially important ones. Many countries have protected their mangroves and forbidden the construction of new shrimp farms in tidal or mangrove areas. The enforcement of the respective laws is often problematic, though, and especially in the least developed countries such as Bangladesh, Myanmar
Myanmar
Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
, or Vietnam the conversion of mangroves to shrimp farms remains an issue for areas such as the Myanmar Coast mangroves
Myanmar Coast mangroves
The Burmese or Myanmar Coast mangroves are an ecoregion in Burma, Malaysia, and Thailand where there were once thick forests of mangroves but today most has been cleared, resulting in loss of habitat for wildlife.-Location and description:...
.
Intensive farms, while reducing the direct impact on the mangroves, have other problems. Their nutrient-rich effluents (industrial shrimp feeds disintegrate quickly, as little as 30% are actually eaten by the shrimp with a corresponding economic loss to the farmer, the rest is wasted) are typically discharged into the environment, seriously upsetting the ecological balance. These waste waters contain significant amounts of chemical fertilizer
Fertilizer
Fertilizer is any organic or inorganic material of natural or synthetic origin that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of crop yields are attributable to commercial fertilizer use...
s, pesticide
Pesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...
s, and antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s that cause pollution
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...
of the environment. Furthermore, releasing antibiotics in such ways injects them into the food chain
Food chain
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...
and increases the risks of bacteria becoming resistant
Antibiotic resistance
Antibiotic resistance is a type of drug resistance where a microorganism is able to survive exposure to an antibiotic. While a spontaneous or induced genetic mutation in bacteria may confer resistance to antimicrobial drugs, genes that confer resistance can be transferred between bacteria in a...
against them. However, most aquatic bacteria, unlike bacteria associated with terrestrial animals, are not zoonotic. Only a few disease transfers from animals to humans have been reported.
Prolonged use of a pond can lead to an incremental buildup of a sludge at the pond's bottom from waste products and excrement. The sludge can be removed mechanically, or dried and plowed to allow biodecomposition, at least in areas without acid problems. Flushing a pond never completely removes this sludge, and eventually, the pond is abandoned, leaving behind a wasteland, with the soil made unusable for any other purposes due to the high levels of salinity, acidity, and toxic chemicals. A typical pond in an extensive farm can be used only a few years. An Indian study estimated the time to rehabilitate such lands to about 30 years. Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
has banned inland shrimp farms since 1999 because they caused too much destruction of agricultural lands due to salination
Soil salination
Soil salinity is the salt content in the soil.- Causes of soil salinity :Salt-affected soils are caused by excess accumulation of salts, typically most pronounced at the soil surface. Salts can be transported to the soil surface by capillary transport from a salt laden water table and then...
. A Thai study estimated 60% of the shrimp farming area in Thailand was abandoned in the years 1989–1996. Many of these problems stem from using mangrove land that has high natural pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
content (acid sulfate soil
Acid sulfate soil
Acid sulfate soils are naturally occurring soils, sediments or organic substrates that are formed under waterlogged conditions. These soils contain iron sulfide minerals or their oxidation products. In an undisturbed state below the water table, acid sulfate soils are benign...
) and poor drainage. The shift to semi-intensive farming requires higher elevations for drain harvesting and low sulfide
Sulfide
A sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...
(pyrite) content to prevent acid formation when the soils shift from anaerobic
Hypoxia (environmental)
Hypoxia, or oxygen depletion, is a phenomenon that occurs in aquatic environments as dissolved oxygen becomes reduced in concentration to a point where it becomes detrimental to aquatic organisms living in the system...
to aerobic conditions.
The global nature of the shrimp farming business, and in particular the shipment of broodstock
Broodstock
Broodstock, or broodfish, are a group of mature individuals used in aquaculture for breeding purposes. Broodstock can be a population of animals maintained in captivity as a source of replacement for, or enhancement of, seed and fry numbers. These are generally kept in ponds or tanks in which...
and hatchery products, throughout the world have not only introduced various shrimp species as exotic species, but also distributed the diseases the shrimp may carry worldwide. As a consequence, most broodstock shipments require health certificates and/or to have specific pathogen free (SPF) status. Many organizations lobby actively for consumers to avoid buying farmed shrimp; some also advocate the development of more sustainable
Sustainability
Sustainability is the capacity to endure. For humans, sustainability is the long-term maintenance of well being, which has environmental, economic, and social dimensions, and encompasses the concept of union, an interdependent relationship and mutual responsible position with all living and non...
farming methods. A joint programme of the World Bank
World Bank
The World Bank is an international financial institution that provides loans to developing countries for capital programmes.The World Bank's official goal is the reduction of poverty...
, the Network of Aquaculture Centres in Asia-Pacific (NACA), the WWF
World Wide Fund for Nature
The World Wide Fund for Nature is an international non-governmental organization working on issues regarding the conservation, research and restoration of the environment, formerly named the World Wildlife Fund, which remains its official name in Canada and the United States...
, and the FAO
Fão
Fão is a town in Esposende Municipality in Portugal....
was established in August 1999 to study and propose improved practices for shrimp farming. Some existing attempts at sustainable export-oriented shrimp farming marketing the shrimp as "ecologically produced" are criticized by NGOs as being dishonest and trivial window-dressing.
Yet, the industry has been slowly changing since about 1999. It has adopted the "best management practices" developed by the World Bank program, for example, and others. and instituted educational programs to promote them. Due to the mangrove protection laws enacted in many countries, new farms are usually of the semi-intensive kind, which are best constructed outside mangrove areas anyway. There is a trend to create even more tightly controlled environments in these farms, with the hope to achieve better disease prevention. Waste water treatment has attracted considerable attention; modern shrimp farms routinely have effluent treatment ponds where sediments are allowed to settle at the bottom and other residuals are filtered. As such improvements are costly, the World Bank program also recommends low-intensity polyculture
Polyculture
Polyculture is agriculture using multiple crops in the same space, in imitation of the diversity of natural ecosystems, and avoiding large stands of single crops, or monoculture...
farming for some areas. Since it has been discovered that mangrove soils are effective in filtering waste waters and tolerate high nitrate
Nitrate
The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...
levels, the industry has also developed an interest in mangrove reforestation
Reforestation
Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted, usually through deforestation....
, although its contributions in that area are still minor. The long-term effects of these recommendations and industry trends cannot be evaluated conclusively yet.
Social changes
Shrimp farming in many cases has far-reaching effects on the local coastal population. Especially in the boom years of the 1980s and 1990s, when the business was largely unregulated in many countries, the very fast expansion of the industry caused significant changes that sometimes were detrimental to the local population. Conflicts can be traced back to two root causes: competition for common resources such as land and water, and changes induced by wealth redistribution.A significant problem causing much conflict in some regions, for instance in Bangladesh
Bangladesh
Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
, are the land use rights. With shrimp farming, a new industry expanded into coastal areas and started to make exclusive use of previously public resources. In some areas, the rapid expansion resulted in the local coastal population being denied access to the coast by a continuous strip of shrimp farms with serious impacts on the local fisheries. Such problems were compounded by poor ecological practices that caused a degradation of common resources (such as excessive use of freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
to control the salinity of the ponds, causing the water table
Water table
The water table is the level at which the submarine pressure is far from atmospheric pressure. It may be conveniently visualized as the 'surface' of the subsurface materials that are saturated with groundwater in a given vicinity. However, saturated conditions may extend above the water table as...
to sink and leading to the salination of freshwater aquifer
Aquifer
An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...
s by an inflow of salt water). With growing experience, countries usually introduced stronger governmental regulations and have taken steps to mitigate such problems, for instance through land zoning
Zoning
Zoning is a device of land use planning used by local governments in most developed countries. The word is derived from the practice of designating permitted uses of land based on mapped zones which separate one set of land uses from another...
legislations. Some late adopters have even managed to avoid some problems through proactive legislation, e.g. Mexico. The situation in Mexico is unique owing to the strongly government-regulated market. Even after the liberalisation in the early 1990s, most shrimp farms are still owned and controlled by locals or local co-ops (ejido
Ejido
The ejido system is a process whereby the government promotes the use of communal land shared by the people of the community. This use of community land was a common practice during the time of Aztec rule in Mexico...
s).
Social tensions have occurred due to changes in the wealth distribution within populations. The effects of this are mixed, though, and the problems are not unique to shrimp farming. Changes in the distribution of wealth tend to induce changes in the power structure within a community. In some cases, there is a widening gap between the general population and local élites who have easier access to credits, subsidies, and permits and thus are more likely to become shrimp farmers and benefit more. In Bangladesh, on the other hand, local élites were opposing shrimp farming, which was controlled largely by an urban élite. Land concentrations in a few hands has been recognized to carry an increased risk of social and economic problems developing, especially if the landowners are non-local.
In general, it has been found that shrimp farming is accepted best and introduced most easily and with the greatest benefits for the local communities if the farms are owned by local people instead of by restricted remote élites or large companies because local owners have a direct interest in maintaining the environment and good relations with their neighbors, and because it avoids the formation of large-scale land property.
See also
- Freshwater prawn farmFreshwater prawn farmA freshwater prawn farm is an aquaculture business designed to raise and produce freshwater prawn or shrimp for human consumption. Freshwater prawn farming shares many characteristics with, and many of the same problems as, marine shrimp farming...
ing shares many characteristics and problems with marine shrimp farming. Unique problems are introduced by the main species' (the giant river prawnGiant river prawnMacrobrachium rosenbergii, also known as the giant river prawn, giant freshwater prawn, Malaysian prawn, freshwater scampi , or cherabin, is a species of freshwater shrimp native to the Indo-Pacific region,...
, Macrobrachium rosenbergii) developmental life cycle. The global annual production of freshwater prawns (excluding crayfishCrayfishCrayfish, crawfish, or crawdads – members of the superfamilies Astacoidea and Parastacoidea – are freshwater crustaceans resembling small lobsters, to which they are related...
and crabCrabTrue crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s) in 2003 was about 280,000 tonnes, of which China produced some 180,000 tonnes, followed by India and Thailand with some 35,000 tonnes each. China also produced about 370,000 tonnes of Chinese mitten crabChinese mitten crabThe Chinese mitten crab, Eriocheir sinensis is a medium-sized burrowing crab, named for its furry claws that look like mittens, that is native in the coastal estuaries of eastern Asia from Korea in the north to the Fujian province of China in the south...
(Eriocheir sinensis). - Shrimp fisheryShrimp fisheryA shrimp fishery is a fishery directed toward harvesting either shrimp or prawns. .-Commercial shrimping:...
- Krill fisheryKrill fisheryThe krill fishery is the commercial fishery of krill, small shrimp-like marine animals that live in the oceans world-wide. Estimates for how much krill there is vary wildly, depending on the methodology used. They range from 125–725 million tonnes of biomass globally...
Footnotes
The terminology is sometimes confusing as the distinction between "shrimpShrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
" and "prawn
Prawn
Prawns are decapod crustaceans of the sub-order Dendrobranchiata. There are 540 extant species, in seven families, and a fossil record extending back to the Devonian...
" is often blurred. The FAO, for instance, calls P. monodon the "Giant Tiger Prawn", but P. vannamei the "Whiteleg Shrimp". Recent aquaculture literature increasingly uses the term "prawn" only for the freshwater forms of palaemonids and "shrimp" for the marine penaeids.
Since adult shrimp are bottom dwellers, stocking densities in ponds are usually given per area, not per water volume.
The taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
of the whole genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Penaeus is in flux. Pérez Farfante and Kensley have proposed a subdivision or reassignment of several species in this genus to new genera based on morphological differences, in particular their genital characteristics. See Penaeus
Penaeus
Penaeus is a genus of prawns, including the giant tiger prawn , the most important species of farmed crustacean worldwide. The genus has been reorganised following a proposition of Pérez Farfante and Kensley based on morphological differences, in particular the genital characteristics of these...
for more information. As a consequence, some of the farmed species are also known under names using the genera Litopenaeus, Farfantepenaeus, Fenneropenaeus, or Marsupenaeus instead of plain Penaeus. Penaeus vannamei, for instance, has become Litopenaeus vannamei.
Accurate statistics on shrimp farming do not exist. The FAO
Fão
Fão is a town in Esposende Municipality in Portugal....
relies on the voluntary reporting of countries for its fisheries databases; if no numbers are reported, the FAO fills in its own "guesstimate". Such estimates are marked in the databases, but these obviously also contain estimates made already by the reporting government agencies, recognizable only by the suspiciously round numbers.
External links
- FAO Fisheries Department: Review of the State of World Aquaculture, FAO Fisheries Circular 886, Rev. 1; FAO, 1997. ISSN 0429-9329.
- Holthuis, L. B.Lipke HolthuisLipke Bijdeley Holthuis was a Dutch carcinologist, considered one of the "undisputed greats" of carcinology, and "the greatest carcinologist of our time"....
: [ftp://ftp.fao.org/FI/document/sidp/AC477E_01Shrimp/AC477E00.pdf FAO Species Catalogue, Vol. I: Shrimps and Prawns of the World], FAOFãoFão is a town in Esposende Municipality in Portugal....
Fisheries Synopsis 125, Vol. 1.; FAO, 1980. ISBN 92-5-100896-5. - McQuaid, J.: Thailand transformed by shrimp boom, March 28, 1996. Part of a series for which the newspaper The Times-Picayune, New Orleans, won the Pulitzer PrizePulitzer PrizeThe Pulitzer Prize is a U.S. award for achievements in newspaper and online journalism, literature and musical composition. It was established by American publisher Joseph Pulitzer and is administered by Columbia University in New York City...
in the category "public service"Pulitzer Prize for Public ServiceThe Pulitzer Prize for Public Service has been awarded since 1918 for a distinguished example of meritorious public service by a newspaper or news site through the use of its journalistic resources. Those resources, as well as reporting, may include editorials, cartoons, photographs, graphics,...
in 1997. - Network of Aquaculture Centres in Asia-Pacific (NACA) has many of the World Bank et al. reports and a lot of current information about shrimp farming in Asia.
- Scampi.nu is a Swedish web site critical of shrimp farming that has many excellent links to English articles.
- Mai Po gei wai is a WWFWorld Wide Fund for NatureThe World Wide Fund for Nature is an international non-governmental organization working on issues regarding the conservation, research and restoration of the environment, formerly named the World Wildlife Fund, which remains its official name in Canada and the United States...
-managed extensive shrimp farm in Hong KongHong KongHong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...
. - Monterey Bay AquariumMonterey Bay AquariumThe Monterey Bay Aquarium is located on the former site of a sardine cannery on Cannery Row of the Pacific Ocean shoreline in Monterey, California. It has an annual attendance of 1.8 million visitors. It holds thousands of plants and animals, representing 623 separate named species on display...
'Seafood Guide' offers good information on choosing seafood that is caught using sustainable and environmentally aware methods. - Environmental Justice Foundation The Environmental Justice Foundation has created several video and written reports about the damaging shrimp farming causes to coastal habitats.
- Shrimp farming, from GreenpeaceGreenpeaceGreenpeace is a non-governmental environmental organization with offices in over forty countries and with an international coordinating body in Amsterdam, The Netherlands...
. - Australian Prawn Farming Manual Download page of the 159 page PDF published by The State of Queensland, Department of Primary Industries and Fisheries