Antioxidant enzyme activities of fish, Oreochromis mossambicus was determined to establish possible environmental impact of toxic effects on anthropogenic pollution of Chrompet Lake. Activities of superoxide dismutase (SOD) and catalase (CAT) in the blood of fish was studies as bioindicator. After sacrificing the fish, fresh blood samples were collected on test tube and stored in ice box. Superoxide dismutase (SOD) activity was measured by the ferricytochrome C method using xantine/ xantine oxidase as a source of superoxide radicals. Catalase (CAT) activity was determinated by measuring the decrease of hydrogen peroxide concentration at 240 nm. Fish have been proposed as indicators for monitoring land-based pollution because they may concentrate indicative pollutants in their tissue, directly from water through respiration and also through their diet. Fish are frequently subjected to prooxidant effects of different pollutants often present in the aquatic environment.
