ENVIRONMENTAL POLLUTION AND FISH MORTALITY AT CHALTIA BEEL, A WETLAND UNDER FISHERMEN CO-OPERATIVE SOCIETY IN MURSHIDABAD DISTRICT OF WEST BENGAL

Anthropogenic factor is an important issue for environmrntal pollution that leads to destruction of aquatic environment. Urban and semiurban wetlands are frequently affected by the direct release of untreated municipal sewage water. It may cause large scale destruction of aquatic organisms, particularly fishes. Chaltia Beel is one of the important wetland of Murshidabad district and is located under Bhakuri Gram Panchayat, adjacent to Berhampore Municipality of the District. Untreated sewage water of the municipality is directly released to the Beel at two points. In this beel, heavy mortality of fishes has been frequently observed and on 22nd August, 2016, all fishes of the beel were died. This beel is managed by a fishermen Co-operative Society, Bhakuri Matshyajibi Samabay Samity Ltd. Now, the livelihood of 71 families of fishermen of this society is under threat. An intensive study of the water quality of this beel and pathological examination of dead fishes have been carried out and it revealed that the frequent mass mortality of fishes of this beel was due to depletion of dissolved oxygen (DO), elevated biological oxygen demand (BOD), high level of molecular ammonia and eutrophication as pathological symptoms were not found in most of the fishes. The need for the good governance to save the aquatic bodies from pollution and protection of livelihood of fishermen has also been discussed.