太平洋刀鱼(Cololabissaira)是亚太国家商业上最重要的中上层鱼类之一。海洋学环境,尤其是Oyashio洋流,显著影响太平洋刀鱼的分布,并可能导致其迁徙路线的变化以及日本沿海地区和公海渔场的形成。在这项研究中,六个海洋学因素,海面温度(SST),海面叶绿素a浓度(SSC),海面盐度(SSS),海面高度(SSH),混合层深度(MLD),和涡流动能(EKE),在2014-2017年的最佳捕捞期(9月至11月),与中国渔船的太平洋刀鱼的每月单位努力捕捞量1(每月CPUE1,吨/船)和每月CPUE2(吨/天)相关。梯度森林分析表明,每月CPUE1的性能高于每月CPUE2,SST是影响每月CPUE1的最重要海洋学因素,其次是EKE。广义加性模型表明,SST,SSH,和EKE负面影响每月CPUE1,而SSC,SSS,和MLD诱导的圆顶形增加每月CPUE1。捕鱼地点的分布很可能沿着Oyashio海流和蜿蜒而形成,尤其是10月和11月。Oyashio入侵面积与相对丰度变化指数之间关系的同步趋势表明,Oyashio入侵面积的增加导致更多的太平洋刀鱼迁移到日本沿海地区,反之亦然。这些发现扩展了我们对海洋学环境对太平洋秋刀鱼的影响的理解。
The Pacific saury (Cololabis saira) is one of the most commercially important pelagic fishes in Asia-Pacific countries. The oceanographic environment, especially the Oyashio Current, significantly affects the distribution of Pacific saury, and may lead to variations in their migration route and the formation of fishing grounds in Japanese coastal region and the high seas. In this study, six oceanographic factors, sea surface temperature (SST), sea surface chlorophyll-a concentration (SSC), sea surface salinity (SSS), sea surface height (SSH), mixed layer depth (MLD), and eddy kinetic energy (EKE), were associated with the monthly catch per unit effort 1 (monthly CPUE1, ton/vessel) and the monthly CPUE2 (ton/day) of Pacific saury from Chinese fishing vessels during the optimal fishing periods (September-November) in 2014-2017. The gradient forest analysis showed that the performance of monthly CPUE1 was higher than monthly CPUE2 and SST was the most important oceanographic factor influencing monthly CPUE1, followed by EKE. The generalized additive model indicated that SST, SSH, and EKE negatively affected monthly CPUE1, whereas SSC, SSS, and MLD induced dome-shaped increases in monthly CPUE1. The distributions of fishing locations are likely to form along Offshore Oyashio current and meanders, especially in October and November. Synchronous trends in the relationship between the intrusion area of the Oyashio and relative abundance variation index suggest that an increase in the intrusion area of the Oyashio causes more Pacific saury to migrate to the Japanese coastal region, and vice versa. These findings extend our understanding of the effects of the oceanographic environment on Pacific saury.