Thursday, October 14, 2010

Water Pollution from Shrimp Farming


In Asia shrimp farming plays a very important role, as it contributes to the overall economic development of the country. As a result of the numerous shrimp farms, there is a very harsh reality for the surrounding environment. Predominately in Vietnam is where a lot of pollution occurs from shrimp farming. From 2008, the area used for shrimp farming has decreased but the
production has increased. This has posed many questions for environmental researchers. The pond sizes have declined about 9% and the amount of shrimps produced has increased by 10%. The farming in Vietnam has not been very successful, with poor soil and the constant disease outbreaks. Farmers tend to turn to pesticides, antibiotics and large amounts of feed in shrimp farming. This has caused the release of harmful pollutants, which can be avoided by using different techniques of farming.

With the use of fertilizers and other chemicals in shrimp farming, it leads to very polluted waste waters. These waste waters end up in the surrounding environment, contaminating the sediment and soil. The fertilizers are used to increase the food for shrimp in the form of algae. This is the main cause of polluting the waters and producing harmful waste waters from the shrimp farming. After two months of the farming operations, the ponds exceeded the standard amount of pollutants. “Antibiotic concentration in shrimp ponds may do harm to the environment and contribute to the increasing drug resistant diseases,” says scientist who is researching the effects of shrimp farming. When the ponds get polluted, this is the perfect environment for pathogenic organisms, which can cause harm. Once the diseases are detected it is even hard to control them because of how open the land and water relationship is. This shows how, we sometimes may not know where our food is coming from and it could lead to an epidemic on a global level.

In Vietnam since money is usually a big issue, this can lead to the farmers unable to provide living conditions for the shrimp. The farmers are unable to buy the correct technologies, which reduce the amount of pollutants from the shrimp farming procedures. The income of shrimp farmers varies a lot, making them hesitant to buy any new equipment for their farms. Also, the farmers fear their shrimp will fail and in return they want to use the chemical to ensure they survive. Vietnam has now introduced the food safety on the their shrimp to ensure disease will not spread. There has recently been less cases of contaminated shrimp in the consumer markets. The farmers just want to make a living and in return cause damage to the environment.

Overall the ways the farmers will be able to reduce the pollution from the shrimp farms is to reduce the amount of feed and use ozone aeration. The ozone aeration procedure increases the quality of the pond water, which reduces the pollution in the water. With less feed there will be less feed residue, which is the cause of the sludge in the ponds. The sludge contaminates the sediment. These two major ways of reducing the pollution in shrimp ponds can make a huge to different in preventing diseases and contamination. As a result most of the shrimp farms in Vietnam are exceeding the amount of the pollution in their ponds. However, there are still a few farms which are obeying the regulations. The farmers will also be greatly affected by the pollution, since the waste waters can enter their water system as well. Is it really worth it to be able to produce a lot of shrimp at the cost of creating destructive diseases?
By: Ashley Venner

References:
Thi Anh,P., Kroeze, C,. Bush, S,. Mol, A. (2010) Water pollution by intenstive brackish shrimp farming in south-east vietnam: causes and options for control. Agricultural water management. Volume 97, issue 6.

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