Esitimation of growth and mortality parameters of Parargyrops edita Tanaka in Beibu Bay

Based on length..frequency data of crimson sea bream Parargyrops edita collected in Beibu Bay in the 1990.. s and 1960.. s growth and mortality parameters were estimated using ELEFAN ..technique in FiSAT. The estimated parameters for von Bertalanffy growth equation was L .. = 27. 3cm , K = 0. 45, t0 = - 0. 34; the turning point on body weight growth curve of the stock was situated at t= 2. 12; the instantaneous rate of total mortality ( Z) was Z = 2. 825, and the instantaneous natural( M) and fishing mortality( F ) rates were 1. 045 and 1. 78 respectively . The exploitrate in recent years was 0. 63, and is in a state of over..exploitation. According to the curve of equal catch, the fishing intensity was too high but the catch age and body..length were too low , so the stocks declined. Considering fishing effort and social..economical benef it, this paper suggests that the optimum catch age should be above one year and body length above 120mm.