Shrimp farming is a form ofaquaculture that takes place in marine or freshwater environments, producingshrimp orprawns[Note 1] (crustaceans of the groupsCaridea orDendrobranchiata) for human consumption. However, the industry has raised concerns about environmental damage tomangrove ecosystems, reliance onslave labor, and animal welfare issues.[1]
Commercial marine shrimp farming began in the 1970s, and production grew steeply, particularly to match the market demands of theUnited States,Japan, and WesternEurope. The total global production of farmed shrimp reached more than 2.1 milliontonnes in 1991, representing a value of nearlyUS$9 billion. About 30% of farmed shrimp is produced inAsia, particularly inChina andIndonesia. The other 54.1% is produced mainly inLatin America, whereBrazil,Ecuador, andMexico are the largest producers. The largest exporting nation is Indonesia.
Shrimp farming has changed from traditional, small-scale businesses inSoutheast Asia into a global industry. Technological advances have led to growing shrimp at ever higher densities, andbroodstock is shipped worldwide. Virtually all farmed shrimp are of thefamilyPenaeidae, and just two species –Litopenaeus vannamei (Pacific white shrimp) 70% andPenaeus monodon (giant tiger prawn) 20% – account for roughly 90% of all farmed shrimp.
These industrialmonocultures used to be very susceptible to diseases, which caused several regional wipe-outs of farm shrimp populations in past decades. Increasing ecological problems, repeated disease outbreaks, and pressure and criticism fromNGOs, consumer countries and even producers themselves, 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 moresustainable farming practices was initiated, including governmental bodies, industry representatives, and environmental organizations.
Freshwater prawn farming shares many characteristics with, and many of the same problems as,marine shrimp farming. Unique problems are introduced by the developmental lifecycle of the main species (the giant river prawn,Macrobrachium rosenbergii).[2] The global annual production of freshwater prawns in 2010 was about 670,000 tons, of which China produced 615,000 tons (92%).[3]
Eyestalk ablation is the removal of one (unilateral) or both (bilateral)eyestalks from acrustacean. In a context of shrimp domestication, ablated females produce more eggs and for a longer time period than non ablated. It is widely practiced on female shrimps (or prawns), both research andcommercial.[1] The aim of ablation under these circumstances is to stimulate the female shrimp to develop matureovaries andspawn.[4]
Even in conditions where a given species will develop ovaries and spawn in captivity, use of eyestalk ablation is considered to increase total egg production and increase the percentage of females in a given population that participate in reproduction. Once females have been subjected to eyestalk ablation, complete ovarian development often ensues within as little as 3 to 10 days.
