Shrimp industry in Sri Lanka developed rapidly during the last decade resulting in rapid degradation of the coastal environment in the North Western province. The land allocation for shrimp culture was less than 500ha in 1985 and increased to over 4000ha by 2000.
Reduction of environmentally sensitive areas has caused a reduction in Biodiversity. The mangrove cover has reduced by 41% due to shrimp culture activities. Migratory bird populations visiting the Mundel area have reduced by 48%. The species diversity in the lagoon fishery has reduced from 19 species in 1991 with catches dominated by Nematolosa nasus to 14 species in 2000 with catches dominated by Arius species. The only shrimp species caught in the Mundel lagoon is Peneaus monodon in small numbers while there was a good fishery for Peneaus indicus and Peneaus semisulcatus in the past.
The Mundel lagoon area has been reduced by 9%. Construction of dykes obstructing natural water drainage has increased the incidence of floods in the area. The water quality deterioration caused by direct discharge of-effiuents to the surrounding water bodies, has resulted in elevation of BOD levels, Nitrite, Ammonia and sulphide levels as well as the water pH and Suspended solid concentrations.
Populations of several pathogenic viral and bacterial species in the coastal area have increased even threatening the wild crustaceans in the natural environment. Use of probiotics to treat water as well as use of chlorine and lime without any technical guidance has resulted in further'aggravating the problems.
Importance of introducing a monitoring system and educating farmers and their technical consultants could help in enhancing production with lesser impacts on the environment.