中西太平洋长鳍金枪鱼渔场重心时空分布研究

Spatial and Temporal Distribution of the Fishing Ground Gravity of Thunnus alalunga in Western and Central Pacific

长鳍金枪鱼作为高度洄游的大洋性鱼类,有较高的经济价值。为掌握中西太平洋长鳍金枪鱼的资源时空分布以可持续开发利用,笔者根据2009—2018年世界各国在中西太平洋的长鳍金枪鱼延绳钓作业数据,利用统计和K-means聚类方法探究长鳍金枪鱼资源的时间变化趋势与空间分布特征。研究结果显示:2009—2018年间长鳍金枪鱼渔场重心主要分布在E 155°~W 160°,S 15°~S 30°海域;北半球冬季(12月—翌年2月)主要集中在北半球低纬度海域(N 0°~N 10°),渔场重心向西北偏移;南半球冬季(6—8月)主要集中在南半球低纬度海域(S 12°~N 22.5°),渔场重心向东南偏移。渔场重心的空间分布受海面温度异常的影响较显著:当海面温度距平值整体偏高时,渔场重心零散分布于中部海域;海面温度距平值相对偏低时,渔场重心向东南与西北两侧偏移。本研究结果有助于中西太平洋长鳍金枪鱼的可持续开发利用与科学管理。

As a highly migratory oceanic fish,Thunnus alalunga has high economic value.The research and analysis of the spatial and temporal distribution of its resources are the basis for further efficient development and utilization and improvement of operational efficiency.This paper was based on the world longline fishing data of Thunnus alalunga in the Western and Central Pacific Ocean from 2009 to 2018.Combined with the data,the monthly variation trend and spatial distribution characteristics of Thunnus alalunga resources were explored by using statistics and K-means clustering method.The results showed that the center of gravity of the fishing ground is mainly distributed in the range of E 155°-W 160°and S 15°-S 30°during 2009-2018.The Northern Hemisphere winter(from December to February of the next year)is mainly concentrated in the low latitude area of the northern hemisphere(N 0°-N 10°),the center of gravity of fishing ground shifts to the northwest,and the southern hemisphere winter(from June to August)is mainly concentrated in the low latitude area of the southern hemisphere(S 12°-S 22.5°),the center of gravity of the fishing ground shifted to the southeast.The spatial and temporal distribution of the center of gravity of the fishing ground is significantly affected by the sea surface temperature anomaly.When the SSTA is higher,the center of gravity of the fishing ground is scattered in the central sea area,and when the SSTA is relatively lower,the center of gravity of the fishing ground shifts to the southeast and northwest.The results are helpful to the sustainable development,utilization and scientific management of Thunnus alalunga in this sea area.