東北・北海道沖の南下サンマの資源動態について-III
東北・北海道沖の南下サンマの資源動態について-III
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关于东北及北海道沿岸的南秋刀鱼资源动态-Ⅲ
DOI：
10.2331/suisan.42.277
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
昌一 田中
中科院分区：
文献类型：
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作者：
義晴 松宮;昌一 田中
1)本文通过对秋刀鱼起网作业渔获量、努力量和渔获物长度组成的统计分析，研究了秋刀鱼在日本北方外海的种群动态。2)考虑到不同大小类的数量动态、体长的年际变化、渔期内的生长以及近海渔场的出现和消失等情况，计算了不同大小类和渔场的数量丰度指数。3)结果表明，各渔场大型鱼类的丰度指数比其他大小类的丰度指数下降得更快、更稳定，但各年的趋势变化较大。4)可用种群的总减少系数对有效捕捞强度的回归分析表明，除大型鱼类外，没有发现正相关关系。q和M值也是根据每10天的数量丰度指数估算的，但对于每个大小类别，往往得到不切实际的负值。5)鱼群的迁移和迁入严重影响了各大小类和渔场的丰度指数和总的减少系数，因此，在今后的分析中，必须建立一个新的模型，结合渔场和海洋学信息的动态。
1) The dynamics of the saury population which occurs in the Pacific Ocean off northern Japan in autumn was studied by analysing the catch and effort statistics of the saury lift net fishery and length composition data of the catch. 2) Taking into consideration such population conditions as the different patterns of the dynamics among size categories, yearly change of body length, growth within the fishing season, and appearance and disappearance of the offshore fishing ground, the abundance index was calculated in terms of number by size category and fishing ground. 3) It was verified that the abundance index of the large sized fish in number by fishing ground was more steadily and rapidly decreasing than that of other size categories, but the tendency was quite variable by year. 4) Regression of the total coefficient of decrease of the available population on the effective overall fishing intensity was examined, but no positive correlation was found except in the large sized fish. The values of q and M were also estimated from the abundance index in number for every 10-day period, but unrealistic nagative values were often obtained for each size category. 5) Emigration and immigration of the fish shoals were considered to affect seriously the abundance index in number by size category and fishing ground, and the total coefficient of decrease; therefore, a new model on the dynamics incorporating the shift of fishing ground and oceanographic information must be developed in the future analysis.