Effects of Pesticides and River Pollution on Fish

River pollution have addressed as most of the sewage and industrial effluents in Dhaka, Bangladesh. Thereby, water quality and seasonal plankton availability of Buriganga, Turag and Shitalakkhya were studied. Moreover, organophosphate pesticides (OPs), those find their ways to aquatic ecosystem adversely affect the aquatic biota. To evaluate the potential hazards, acute toxicity test, histopathology and acetylcholineesterase (AChE) activity were determined. To assess the effects of river pollution at cellular and molecular level, Labeo rohita and Barbonymus gonionotus were exposed to Envoy, Samcup and Darsban at and below the agricultural recommended dose. Both the pollutants and organophosphate pesticides abruptly altered the normal structure in various fish organs. AChE activity in Heteropneustes fossilis and L. rohita brain were also inhibited significantly (P 0.01) due to the pollutants and pesticides exposure, respectively. B. gonionotus showed significant inhibition (P0.05)of that enzyme exposed to Samcup and Darsban. This study implies that both pollution and pesticides pose a great threat to the aquatic biota.