Abstract:In order to investigate the effect of cage-culture of piscivorous fishes on water environment, the Fuqiaohe Reservoir (110°52′30″E, 31°10′N) was selected to study the optimum carrying capacity of mandarin fish (Siniperca chuatsi).Water samples were collected every month ,from July 1998 to October 1998. The parameters monitored were water temperature, water depth, Secchi degree (SD), pH, dissolved oxygen (DO) and main nutrients (various state of nitrogen and phosphorus). Phosphate contents in the body of man...