Graduate School of Environmental Science, Hokkaido University, Hakodate, Hokkaido, Japan.
Estuary Research Center, Shimane University, Matsue, Shimane, Japan.
PLoS One. 2021 Nov 30;16(11):e0260629. doi: 10.1371/journal.pone.0260629. eCollection 2021.
The Kuroshio Current can take two paths; usually it follows the regular pattern but occasionally it follows a pattern known as the large meander. In this study, we investigated the abundance of fish that migrate to coastal waters and the spatial distribution of fish schools under both Kuroshio patterns in Suzu district, Kochi prefecture, where the set net is the main fishery industry. We clarified the seasonal variation in the density and distribution of fish schools using a quantitative echo sounder. The effects of the Kuroshio large meander (LM) depended on the season. There was no effect of current pattern in summer or autumn, but in winter and spring the LM altered the marine environment and fish distributions. Cold water masses were formed in the survey area during winter and spring during the LM, and the water temperature dropped significantly compared with during the Kuroshio non-large meander (NLM). This altered the fish species and the distribution of fish schools in the survey area. The catches of Japanese horse mackerels (Trachurus japonicus) and Yellowtails (Seriola quinqueradiata) were much higher during the LM compared with those during the NLM. Unlike these two species, the small-sized pelagic fishes in spring has decreased significantly during the LM.
黑潮可以有两条路径；通常它遵循常规模式，但偶尔也会遵循一种被称为大弯曲的模式。在这项研究中，我们调查了迁移到沿海水域的鱼类丰度和鱼类洄游群体的空间分布，在黑潮模式下，高知县须崎地区以定置网渔业为主。我们使用定量回声测深仪阐明了鱼类洄游群体密度和分布的季节性变化。黑潮大弯曲（LM）的影响取决于季节。在夏季和秋季，没有潮流模式的影响，但在冬季和春季，LM 改变了海洋环境和鱼类分布。在冬季和春季的 LM 期间，调查区域形成了冷水团，水温与非大弯曲（NLM）期间相比明显下降。这改变了调查区域的鱼类种类和鱼类洄游群体的分布。在 LM 期间，日本马鲛鱼（Trachurus japonicus）和黄鳍金枪鱼（Seriola quinqueradiata）的渔获量明显高于 NLM 期间。与这两个物种不同，春季小型中上层鱼类的数量在 LM 期间显著减少。
