基于信息增益技术比较分析智利和秘鲁外海茎柔鱼渔场环境

茎柔鱼(Dosidicus gigas)是短生命周期物种,广泛分布在东太平洋海域。其资源大小和分布受不同时空尺度的气候变化影响。根据我国鱿钓船生产数据,结合卫星遥感获取的环境资料,利用信息增益技术对东太平洋智利和秘鲁外海两个海区茎柔鱼栖息环境进行比较分析。可以得出,智利和秘鲁外海茎柔鱼中心渔场分布对应的适宜表温(SST)范围分别是15~23℃和16~25℃,且每月最高作业频次对应的SST值具有明显的季节性特征,与SST平均值关系密切。信息增益技术结果表明,智利外海和秘鲁外海影响中心渔场分布的关键环境因子基本相同,主要为SST、55米层水温(T55)、表层至55米层的水温梯度(G0-55)。研究认为,不同海域表征茎柔鱼中心渔场的主要环境因子是有差异的,这一差异主要由其海洋环境大背景所决定。

A comparison of habitats of Dosidicus gigas in the fishing ground off Chile and Peru based on information gain technique

Jumbo flying squid （Dosidicus gigas ） is a kind of short life cycle species, which is widely distributed in the eastern Pacific Ocean. The abundance and distribution of D. gigas are highly subjected to the fluctuated environmental conditions from the spawning and fishing ground in different spatio-temporal scales. In this study, we use the fishing data from the Chinese squid jigging fleets to compare the habitats in the open waters of Chilean and Peruvian EEZs and the high sea in Equator by using the information gain technology （IGT）, combined with the data obtained from the satellite remote sensing. The research showed that the range of suitable sea surface temperature （SST） in the central fishing ground in the open waters of Chilean and Peruvian EEZs are 15 - 23 ~C and 16 - 25 ~C, respectively. The SST corresponding to the largest fishing frequency showed obvious seasonal variability and has a close relationship with the monthly average SST. The result of the information gain technology indicated that the key factors affecting the distribution of fishing ground of Dosidicus gigas in the open waters of Chilean and Peruvian EEZs are SST, T55 and G0-55. The environment factors affecting the fishing ground were basically the same between Chile and Peru. The study suggested that there were differences in the key environmental factors indicating fishing ground of Dosidicus gigas in different waters, which were mainly caused by different marine environment.