ENSO现象与东太平洋黄鳍金枪鱼围网CPUE时空分布的关系

黄鳍金枪鱼是东太平洋金枪鱼围网渔业中的主要渔获种类之一。根据1975-2004年东太平洋（30°N～25°S，75°W～145°W）黄鳍金枪鱼围网生产统计资料和相应年份的Nino3区的指数，利用灰色关联度方法对ENSO现象与黄鳍金枪鱼资源丰度及时空变化的关系进行了分析。研究结果发现，ENSO现象对东太平洋黄鳍金枪鱼围网资源丰度及时空分布有显著影响，在大部分厄尔尼诺年时，黄鳍金枪鱼围网作业重心会向东、向北移；而拉尼娜年则向西移。Nino3指数与单位捕捞努力量渔获量（CPUE）存在负相关关系。此外，黄鳍金枪鱼围网作业重心在年内也呈现出规律性变化，春夏季向西、向北移；秋冬季向东、向南移。春夏季的单位捕捞努力量渔获量高于秋冬季。

The relationship between ENSO and spatio temporal distribution of CPUE of yellowfin tuna(Thunnus albacares) by purse seine in the Eastern Pacific Ocean

Yellowfin tuna(Thunnus albacares) is a major target species of the tuna purse seine fishery in the Eastern Pacific Ocean. Based on yellowfin tuna purse seine fisheries data in the Eastern Pacific Ocean(30°N-25°S,75°W-145°W)from 1975 to 2004 and the corresponding Nino3 index(sea surface temperature anomaly), the relationship between ENSO and yellowfin tuna stock abundance and its spatio temporal distribution are analyzed by using grey relationship analysis method in this study. Preliminary results indicate that ENSO episodes affect the stock abundance and spatio temporal distribution of yellowfin tuna significantly. During El Nino periods, the fishing gravity center moves to the east and the north, whereas to the west during La Nina periods. There is a negative relationship between Nino3 index and CPUE. Furthermore, there is a siginifcantly regular annual change for the location of fishing gravity center. In the spring and summer, the fishing gravity center turns to the west and to the north, but it moves to the east and the south in the autumn and winter. The CPUE of the spring and summer is higher than that of the autumn and winter.