东海鲐鱼资源合理利用的研究

利用1970~2006年每年取样鲐鱼所得叉长体重组构成资料,重点分析了70、80、90年代的鲐鱼生物学表征;并结合我国围网捕捞的发展变化情况,应用体长结构实际种群分析法(LVPA)对各个年代的鲐鱼捕捞死亡系数(F)做了分析对比,研究显示,东海区日本鲭F由70年代的0.68上升为90年代的1.60,开发利用程度在不断地加大中。根据1990年以来的日本鲭渔获量资料,估算了1990~2001年东海区日本鲭资源量,结果表明,东海区日本鲭年平均资源量在(73.34~116.88)×104t之间波动。以LVPA法估算所得的90年代鲐鱼F值和最小开捕叉长的数据,利用B-H动态综合模型估算了不同渔业条件下的单位补充量渔获量(Y/R)的变化,结果显示,以目前的捕捞强度,日本鲭的开捕年龄从0.25龄提高为1.22龄,即最小开捕叉长由185 mm调整为247.61 mm,Y/R可提高15.1%,具有一定增产潜力。建议在实际渔业中,渔期适当推迟,禁止利用日本鲭幼鱼。

Study on the reasonable utilization of chub mackerel in the East China Sea

Based on the data of chub mackerel caught by purse seine from 1970 to 2006 in East China Sea,present article deals with the research on the chub mackerel's biological characters in 1970s,1980s and 1990s by using LVPA method and combining on the variation and development of purse seine fishing in China,as well as comparison on the F value of chub mackerel in different lengths.The research result shows that the fishing mortality coefficient has risen from 0.68 to 1.60,the exploitative extent of the fish resources is being expanded.According to the catches of the fish since 1990,the resource number of chub mackerel is estimated,the average biomass fluctuated between 73.34-116.88×104 t from 1990 to 2001 by using LVPA method to get the F value and the minimal fork-length in 1990s and by using B-H dynamic integrate model,the variations of Y/R of the chub mackerel in the East China Sea in different fishing conditions have been estimated.It comes to conclusions that when we increase the initial catching age from 0.25 to 1.22 namely to adjust the minimum foke-length of the initial catching individuals from 185 to 247.61 mm,the yield per recruit can increase 15.1%.The total yield weight can be enhanced if we utilize the resources of chub mackerel by deferring fishing period appropriately and preventing young fish utilization.