Preliminary Research on the Rational Utilization of Psenopsis anomala in the Offshore Water of South Zhejiang

WANG Ying-bin, YU Cun-gen, YU Cong-da, et al (Fishery School of Zhejiang Ocean University, Zhoushan 316004, China)

offshore water of south Zhejiang; Psenopsis anomala; first capture standard; rational utiliza- tion

Based on data collected from bottom trawl fishery survey in the offshore water of south Zhejiang at four seasons during May 2006 and February 2007, the growth parameters of Psenopsis anomala were estimated using FiSATⅡ software and the effects of yield per recruit(Y/R) caused by the variations of fishing mortality coefficient (F) and first capture age (tc) were analyzed. The optimum first capture age was estimated using Beverton-Holt yield per recruit model, and the corresponding optimum first capture length were calculated using von Bertalanffy growth function. Then the first capture standard was made according to the inflexion length, critical length and the minimum sexual mature age beside the optimum first capture length. Finally, the rational utilization of P. anomala resource was discussed preliminarily. Results shows that the growth parameters are L∞=192 mm, K=0.69 and t0=-0.67. The exploitation rate E is 0.8, which indicate the P. anomala resources in this sea area are already serious overexploited. The authors suggest that the first capture standard should be 150 mm, based on the research results, and corresponding age is 1.5 a. The F should be drop to about 2.0gradually, then the YW /R will be 157.1 g, which will increase 59.5% compared with present fishery yield.