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

Abstract:

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 ℃ and 16-25 ℃, 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 G_0-55. 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.