摘要:根据1990、1998年鲢、鳙渔获物的年龄组成,相关年份的放养尾数及1995年后的历年捕获量,结合可捕群体、补充群体等假设条件,利用修正的"恒定参数系统法"拟合分析了1995年溢洪后大伙房水库鲢、鳙的残存率、死亡系数、回捕率,探讨了′95溢洪对该水库鲢、鳙渔业的影响,并根据理论捕获量推算出溢洪造成的损失分别为鲢250~350 t,鳙237~436 t.
摘要: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-1.003X2,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,并估算了各类死亡值.用Cohort分析方法估算了放流虾到开捕时(8月15日)的存活数量,平均占放流量的10 .5%.渔汛的捕捞死亡率约0.82,自然死亡率0.11,其余0.07游出黄海北部去越冬场.%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.
Agricultural and Biological Sciences:Aquatic Science;Ecology, Evolution, Behavior and Systematics;Environmental Science:Management, Monitoring, Policy and Law;