中西太平洋金枪鱼围网自由鱼群渔场重心变动及其与南方涛动指数的关系

文章根据2013—2017年中国中西太平洋金枪鱼围网船队捕捞日志,利用捕捞自由鱼群作业位置、作业时间和渔获量等数据信息,分析了自由鱼群渔场重心月间变化、年际变化与南方涛动指数(South Oscillation Index,SOI)的关系。结果显示,渔获量较高的海域海表温度(Sea surface temperature,SST)高于29℃;自由鱼群的渔场重心主要分布介于160°E—175°W;2013—2015年渔场重心有逐年向东偏移的趋势,但无明显的月间变化规律;SOI为正值时,中西太平洋“暖池”较正常年份向西偏移,自由鱼群渔场重心亦明显向西偏移;反之,自由鱼群渔场重心较正常年份向东偏移。相关性分析显示SOI和月间渔场重心的经度之间呈负相关(相关系数为?0.27,P<0.05),表明金枪鱼围网渔场变动和异常气候的发生存在密切联系。研究结果对于掌握中西太平洋金枪鱼围网渔场变动规律具有一定参考价值。

Variation of fishing ground gravity of tuna free-swimming school caught by purse seiner in Western and Central Pacific Ocean and its relationship with Southern Oscillation Index

Based on the data of fishing positon,fishing date and catch of free-swimming school from the logbooks of Chinese tuna purse seine fishing fleet operating on the Western and Central Pacific Ocean during 2013 and 2017,we analyzed the relationship between monthly and yearly variation of fishing grounds gravity of free-swimming school and the South Oscillation Index(SOI)obtained from the US Climate Analysis Center.The results show that more catch was found in the fishing areas with sea surface temperature(SST)above 29.5℃.The fishing ground gravity was mainly distributed between 160°E and 175°W.The gravity center had an eastward tendency from 2013 to 2015 without evident monthly variation.The"warm pool"and the gravity center of the Western and Central Pacific Ocean moved towards the west when SOI was positive,while the gravity center moved eastwards when SOI was negative.Correlation analysis shows a significant negative correlation between SOI and fishing ground gravity(the correlation coefficient was?0.27,P<0.05),indicating that there was a close relationship between the change of fishing ground gravity center and climate change.The study helps understand the variation law of fishing ground of tuna purse seine fishery in the Western and Central Pacific Ocean.