Shrimp Aquaculture in Thailand

Extensive shrimp culture was first practised in Thailand 5 to 6 decades ago. In th e shrimp/rice rotating system that was developed, tides regulated the water quality.

Destruction of mangroves was minimal since culture activities were on a small-scale.

In the 1970s, the country began to expand its hatchery potential (for the production of shrimp larvae to stock in aquaculture ponds), largely with Taiwanese assistance. Thailand grew to be the largest exporter of cultured shrimp in Asia, as production increased form 17,886 metric ton (MT)in 1986, to 110,000 tons in 1991. The consequent environmental and social problems have been substantial. Shrimp farming has contributed to the degradation of

mangroves, as mangrove forests were destroyed to build aquaculture ponds, especially in central Thailand, and to some extent in eastern and southeastern Thailand.

Although the Department of Fisheries has been very supportive of the shrimp farming industry,its unregulated expansion, increased mangrove destruction, overstocking, poor drainage and pollution problems in the industry, prompted the DOF to introduce new licensing arrangements and stricter pollution controls for shrimp farmers in 1991. However, these measures have proven to be largely ineffective because very few of the shrimp farmers have agreed to register their farms, which are often located in mangrove forests.

Concentrated intensive shrimp farming has caused a large amount of coastal pollution in many parts of the country. As a result of this, many shrimp farms in Thailand have failed, especially in central and eastern Thailand. In other areas where coastal pollution has become critical, excessive amounts of chemical additives and antibiotics have been used to keep diseases from killing off whole crops of shrimp. In many cases these additives have failed to control diseases.

On the contrary, they have contributed to greater pollution problems and even the chemical contamination of the cultured shrimp themselves. In 1991 Japan rejected a large quantity of Thai cultured shrimp because they were chemically contaminated. While Thailand has made an effort to keep shrimp contamination levels down, there has been very little effort made to reduce the chemical contamination of coastal waters as a result of the use of often dangerous chemicals.

In Thailand, the release of brackish wastewaters by shrimp farms has lead to the contamination of orchards, rice farms and fresh water canals. This problem has severely affected coastal areas in many provinces, including Nakhon Srithammarat and Songkhla. Many rice farmers have watched helplessly as shrimp farming has destroyed their farms and livelihood. Small-scale fishers have also found that coastal pollution and mangrove destruction generated by the industry has caused local fisheries to decline throughout the country.

At the same time, while some shrimp farmers have become wealthy, just as many have been ruined after the environment became poisoned and their valuable crops of shrimp became disease-ridden.

Since intensive shrimp farming requires large quantities of both salt and fresh water, the

industry has also pumped up excessive amounts of groundwater to fill shrimp ponds in many

parts of Thailand. This has led to serious subsidence and water shortage problems in many

areas. It has also made it easy for shrimp farm wastewaters to contaminate ground water

aquifers and village wells. In many cases this has left locals without enough drinking water, let

alone water for agricultural purposes.