Basic Investigation of Fishery Biology of Tianjia Lake in Tianjin

On the basis of handbook of fishery natural resource investigation in inside water area, the water quality, plankton, benthon and fishery were investigated in Tianjia lake in Tianjin. The results indicate that the favourable water quality was fit for the fish growth, but the poor plankton could not supply full food for silver carp and bighead. The silver crucian carp Carassius auratus gibelio was main catches in Tianjia lake.In the future,the silver crucian carp should be bred mainly with few silver carp Hypophthalmichthys.mditrix(c.et.v) and bighead Aristichthys nobilis (Richaxclson) in the Tianjia lake. The length of fish bred in the lake should be more than 12 cm for raising the fish survival rate and catching rate.The fierce fishes should be controlled.