东太平洋不同海域环境因子对茎柔鱼分布的影响差异分析OA北大核心CSTPCD

Jumbo flying squid Dosidicus gigas is widely distributed in the Eastern Pacific Ocean.It has a short-lived life cycle and tends to extremely respond to environmental and climate variability.In order to investigate the difference of the effects of environmental factors on habitat distribution of Dosidicus gigas in different regions in the Eastern Pacific Ocean,the present study developed a habitat distribution model for this squid in summer and autumn in the equator,off Peru and Chile.The fisheries data in the equatorial waters of the Pacific Ocean,the waters off Peru from 2016-2018,and the waters off Chile from 2015-2017 were used and obtained from National distant-water fisheries data center of China.Seven marine environmental factors including Sea surface temperature(SST),Eddy kinetic energy(EKE),Sea surface salinity(SSS),Sea surface height(SSH),Chlorophyll concentration(Chl.a),Mixed layer depth(MLD),and Dissolved oxygen concentration(DO)were considered in this study.The maximum entropy model(MaxEnt)was applied to investigate the distribution of suitable habitat for Dosidicus gigas and the differences in the effects of the environmental factors on it were examined in different seasons in different waters.The results showed that the AUC values of the maximum entropy model were higher than 0.8 in different seasons in different areas,and the actual fishing locations coincided with the range of suitable habitats fitted by the model.The distribution of optimal habitats in the three regions was as follows:in the equatorial waters in summer,the optimal habitats were mainly distributed within the ranges of 110°W-120°W,1°N-3°S;in autumn,the optimal habitats for Dosidicus gigas were mainly distributed within the ranges of 97°W-117°W,1.5°N-1.5°S,and the distribution of suitable habitats was extended to the east from summer to autumn.In summer,the optimal habitats of Dosidicus gigas off Peru were mainly located in the range of 75°W-86°W,15°S-20°S;in autumn,the optimal habitats of Dosidicus gigas were mainly located in the range of 75°W-84°W,15°S-20°S,with the optimal habitats moving southeastward from summer to autumn.The optimal habitats of Dosidicus gigas in summer off Chile were mainly distributed in the range of 73°W-85°W,20°S-30°S;in autumn,the optimal habitatswere mainly distributed in the range of 75°W-85°W,20°S-28°S,and the overall suitable habitats moved to the northeast from summer to autumn.Based on the contribution rate of each environmental factor in the habitat model,SSH,Chl.a,SSS and SST were the important environmental factors affecting jumbo flying squid habitat in the equatorial waters;SSH,MLD,DO and SST were the important environmental factors affecting jumbo flying squid habitat in the offshore Peru,and SSH,SST,Chl.a and MLD were the important environmental factors affecting jumbo flying squid habitat in the offshore Chile.Our findings suggested that significant geographical difference was shown in the environmental factors affecting Dosidicus gigas distribution in different regions.