基于灰色系统理论的西北太平洋柔鱼CPUE关联聚类分析

Correlation clustering analysis of CPUE of neon flying squid(Ommastrephes bartramii)in the northwest Pacific based on grey system theory

利用灰色关联聚类方法对1998—2017年5—12月柔鱼(Ommastrephes bartramii)的单位捕捞努力量渔获量(CPUE)进行聚类,分析不同强度厄尔尼诺和拉尼娜事件以及环境因子对柔鱼CPUE的影响。结果表明:年纬度向类群比年经度向类群的CPUE差异更明显,月经度向类群比月纬度向类群更具有季节性;强拉尼娜和弱拉尼娜事件集中的类群分类明显,厄尔尼诺、中强度拉尼娜和正常年份分类较模糊,年纬度向类群CPUE越高,海表面温度距平值(SSTA)越高,而叶绿素a质量浓度距平值(CHLA)越低。研究表明,不同强度的异常气候事件对柔鱼CPUE影响不同,强拉尼娜事件会使柔鱼CPUE骤增,弱拉尼娜事件会使柔鱼CPUE略减,而中强度以上的厄尔尼诺事件会使柔鱼CPUE大幅度下降。

The neon flying squid(O.bartramii)is a short-lived species which is an important fishing and development target in the Northwest Pacific.In this paper,we used the grey correlation clustering method to cluster catch per unit effort(CPUE)of neon flying squid from May to December,1998-2017,and analyzed the effects of El Ni1 o and La Ni1 a events with different intensities and environmental factors on CPUE.The results show that the CPUE difference between the annual latitude groups and the annual longitude groups is more obvious.The monthly latitude groups are more seasonal than the monthly latitude groups.The groups with strong La Ni1 a and weak La Ni1 a events are significant.The higher CPUE of the annual latitude groups,the higher the sea surface temperature anomaly(SSTA)and the lower the chlorophyll a concentration anomaly(CHLA).The studies have shown that abnormal weather events of different intensities have different effects on CPUE in neon flying squid.Strong La Ni1 a events can increase CPUE of neon flying squid,weak La Ni1 a events can slightly reduce CPUE,and El Ni1 o events above moderate intensity can cause CPUE to decrease significantly.