西北太平洋公海7~9月秋刀鱼渔场分布及其与水温的关系

根据2003~2005年7~9月西北太平洋公海秋刀鱼生产数据和水温遥感数据,对西北太平洋公海秋刀鱼作业渔场分布及其与表温和上层水温结构的关系进行了分析。结果认为,随着时间的推移,7~9月西北太平洋公海秋刀鱼渔场重心有从西南向东北变动的趋势;各月产量重心处水温结构有较大差异,9月混合层深度较7月和8月有所加深,渔场也较后者向北移动;各月高产渔区0~15m温度梯度都在0.25℃/m以下,0~40m温度梯度在0.1℃/m左右,40~60m温度梯度在0.25~0.42℃/m之间。灰色关联度分析表明,渔区月产量受到众多因素的影响,其中捕捞努力量、渔区平均日产量和表温是其主要影响因子,对渔区平均日产量影响较大的有表温、0~15m温度梯度、0~40m温度梯度和月份,其关联度都在0.80以上。

The fishing ground distribution of Cololabis saira and its relationship with water temperature factors in the Northwestern Pacific from July to September

Based on the catch data collected by Chinese fishing vessels and water temperature data obtained from remote sensing on the saury fishing grounds in the Northwest Pacific Ocean from July to September during 2003-2005,the fishing ground distribution and its relationship between sea surface temperature(SST) and vertical structures on the Northwest Pacific saury fishing grounds were analyzed.The results indicated that the movement of barycenter of catch had a tendency from southwest to northeast.The vertical structures in the water temperature profiles changed greatly with year and month in barycenter of catch.The mixed layer in September was deeper than that in July and August,and the fishing grounds moved towards north accordingly.On high productive fishing grounds,the temperature gradients 0-15 m in depth were all below 0.25℃/m,those 0-40m in depth were mostly 0.1℃/m,and those 40-60m in depth were between 0.25℃/m and 0.42℃/m.The analysis on degree of grey incidence indicated that the catch was affected by various factors,in which fishing effort,abundance index and SST were the most important factors.The factors that affect on the saury distribution and fishing grounds were SST,temperature gradients at depths of 0-15m and 0-40m,and month,with the values of degree of grey incidence were all above 0.8.