黄海北部中国对虾增殖

根据１９８５￣１９９２年黄海北部中国对虾幼虾放流前后相对资源量资料，估算放流虾在混合虾群中占的平均比例约为９２％，平均回捕率９．２％。放流量（Ｘ）与放流后相对资源量（Ｙ）的关系为Ｙ＝２４．１０Ｘ－１．００３Ｘ＾－２，Ｒ＝０．８９８。经Ｆ－检验相关显著。结果表明：中等放流量才能获最好增殖效果；与最大渔获量相应的放流量约１６亿尾；与最大相对资源量相应的放流量约１２亿尾。描述了放流虾的死亡特征，并估算了

Enhancement of Chinese shrimp in northern Yellow Sea, China

Based on the abundance index of young Chinese shrimp pre- and post-releasing in northern Yellow Sea during 1985～1992,the percentage of released amount in mixed stock (wild and released) was estimated as 92% in a verage, and the mean recapture rate was 9.2%. The relationship between the post released abundance index (Y) and released amount (X) can be presented as Y=24.01X-1.00 3X2,R=0.898. The sign ificance of correlation is significant when examined by using of F test. The bes t effect of enhancement can be obtained with a medium released amount.The optimu m released amount corresponding with the maximum yield was 1.6 billion ins, and that with the maximum abundance index was about 1.2 billion ins.The death charac ter of the released shrimp was described and the mortalities under different con ditions were estimated. Up to opening date(August 15) the survival amount with C ohort Analysis was about 10.5% of the released. The fishing mortality was 0.82 a nd the natural mortality was 0.11 during the fishing season. The rest 0.07 of th e released amount migrated to the wintering ground out of northern Yellow Sea.