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本文讨论了渤海对虾(Penaeus orientalis Kishinouye)的自然死亡,估算了它的世代数量和捕捞死亡系数等。 1.用滑动平均数资料,估算了秋汛渤海对虾的旬自然死亡系数,约为0.038,其真值在0≤M<0.194。 2.用世代分析方法估算了秋汛渤海对虾10个世代在9月初的资源量。经过三个月的捕捞,到12月初,约捕出雌虾77％,自然死亡13％,游出渤海约10％;捕出雄虾约59％,自然死亡约37％,游出渤海不到5％。 3.估算了分旬的捕捞死亡系数,雌雄虾相近,约为0.23。近岸虾流网等网具造成的捕捞死亡系数,1977—1979三年平均值约为0.15,约占总捕捞死亡系数的8％。因它的作业期早,近岸网具渔获量占总渔获量的18.6％左右。1981年已达30％。
This article discusses the natural death of Penaeus orientalis Kishinouye, and estimates its generation and fishing mortality. 1. By using the moving average data, the natural death coefficient of ten days in Bohai Sea in autumn was estimated, which is about 0.038, whose true value is 0≤M <0.194. Using the generational analysis method, the resources of 10 generations of Bohai shrimp in the autumn flood season in early September were estimated. After three months of fishing, by early December about 77% of females were caught, 13% of them died naturally and about 10% of Bohai Sea were caught. About 59% of males were caught and about 37% of natural deaths occurred, leaving the Bohai Sea less than 5%. 3. Estimated sub-ten fishing mortality factor, male and female similar, about 0.23. The fishing mortality caused by nets, shrimp nets and other nets near the shore, the average of 1977-1979 three years is about 0.15, accounting for about 8% of the total fishing mortality. Due to its early operation, nearshore net catches accounted for about 18.6% of the total catch. In 1981 it reached 30%.