Friday, September 22, 2006

Environmental Impacts of Shrimp Farming in Sri Lanaka

Duminda Perera

The problems related to the environment in the shrimp farming industry in Sri Lanka arose mainly from over–emphasis on high production, economic viability and foreign income generation without full consideration of the environmental impacts caused by over-crowding of farms. At the inception, there was no proper zoning plan to facilitate development of an environmentally sound industry. Lack of a proper zoning plan for the northwestern and western provincial coastal belts led to many social problems and destruction of ecologically sensitive areas, such as mangroves and mud flats.

Destruction of mangroves leaves coastal areas exposed to erosion, flooding and storm damage alters natural drainage patterns, increases salt intrusion and removes critical habitats for many aquatic and terrestrial species, with serious implications for biodiversity, conservation and food security. Mangrove estuaries are also specially rich and productive ecosystems and provide the spawning grounds for many species of fish including many commercially important ones.

Nutrient rich effluents of shrimp farms are typically discharged into the environment seriously upsetting the ecological balance. These waste waters contain significant amounts of chemical fertilizers, pesticides and antibiotics that cause severe pollution of the environment.

Other main environmental impacts are pollution and depletion of drinking water, retention of flood water and more frequent floods in the area. Agricultural activities of the area is also seriously affected due to conversion of agricultural lands in to ponds, salinization of water, deposition of salt in the soil and lowering of the water table.

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