南海北部花斑蛇鲻生长死亡参数估计及开捕规格

将南海北部花斑蛇鲻分成南海北部大陆架和北部湾两个不同海域群体 ,计算花斑蛇鲻的生长与死亡参数。得到的VonBertalanffy生长方程的相关参数为 :南海北部大陆架L∞ =4 5.5cm ,K =0 .2 8,t0 =- 0 .4 6 0 ;北部湾L∞ =4 0 .0cm ,K =0 .30 ,t0 =- 0 .4 43。计算自然死亡系数得南海北部大陆架为 0 .6 3;北部湾为 0 .6 7;捕捞死亡系数南海北部大陆架为 0 .79,北部湾为 1.11。据等渔获量曲线建议南海北部大陆架花斑蛇鲻开捕体长由 13.3cm增加至 2 0 .0cm ,同时 ,捕捞死亡系数可由当前的 0 .79放宽至 1.0 ;北部湾花斑蛇鲻开捕体长由 13.5cm增加至 19.0cm的同时 ,捕捞死亡系数可由当前的 1.11放宽至 1.5。

Estimate for Growth, Mortality Parameters and First Capture Specification Suggestion of Saurida undosquamis (Richardson) in Northern South China Sea

Saurida undosquamis (Richardson) in northern South China Sea were divided into the colony in continental shelf of northern South China Sea and the colony in Beibu Bay. Then growth and mortality parameters were estimated. The results showed as followed: the growth parameters of Von Bertalanffy growth equation was L ∞=45.5 cm,K=0.28,t 0=-0.460 for colony in continental shelf of northern South China Sea and L ∞=40 cm,K=0.30,t 0=-0.443 for colony in Beibu Bay; Natural Mortality Coefficient (M) was 0.63 for colony in continental shelf of northern South China Sea and 0.67 for colony in Beibu Bay; Fishing Mortality Coefficient (F) was 0.79 for colony in continental shelf of northern South China Sea and 1.11 for colony in Beibu Bay. According to the curve of equal catch, this paper suggests that L c should be increased from 13.3 cm to 20.0 cm in body-length while F may be increased from 0.79 to 1.0 for colony in continental shelf of northern South China Sea and 19.0 cm from 13.5 cm in body-length while F may be increased from1.11 to 1.5 for colony in Beibu Bay.