绿鳍马面魨生长和资源评析

Growth and Resource Assessment of Thamnaconus septentrionalis

测定从东海区渔轮拖网渔获中取样的299 尾绿鳍马面魨的全长和体重,用其脊椎骨的第3 节椎体作为观察和测定年轮的材料,测出各年龄鱼的年轮轮径及椎体半径,算出各年龄鱼的平均逆算全长,结合全长与体重之间的关系求出生长参数,分析全长、体重生长情况,再根据绿鳍马面魨的自然死亡系数M＝ 0．257 和1992 年的捕捞死亡系数F＝ 1．319,用B－H 模型进行资源评析,评估资源利用程度及最佳利用方案。结果表明：东海绿鳍马面魨资源已过度开发,应采取降低捕捞强度、控制网目尺寸、将开捕年龄推迟为3 a(对应全长224 m m 、体长190 m m )等措施来保护其资源。

Thamnaconus septentrionalis were sampled from the trawler fished in East China Sea, partly in 3～4/1991 and partly in 4/1992. Their total length and their body weight have been measured. Their third vertebra of backbone were used to determine growth ring and used to measure ring length. The growth ring length and the vertebra radius of different fish have been measured, the inverse operation total length of different age were calculated, the growth paramaters of Thamnaconus septentrionalis were calculated. The growth situations of the total length and the body weight were analysed, and the resource was assessed by using B H Model based on the natual mortalith coefficient M =0.257 and the 1992's fishing mortalinty coefficaient F =1.319. The result shows, the resource of Thamnaconus septentrionalis of East China Sea had already been to overfish. To protect this resource to use, the fishing mortality coefficient must be reduced, and the first capture age shoud be put off to 3 ages (total length 224 mm, body length 190 mm) by limiting the mesh.