Sthenoteuthis oualaniensis fishing grounds analysis based on marine environment factors and different weight coefficient in the Zhongsha and Xisha Islands, South China Sea

Based on the survey data of Nanfeng fishery research vessel and the data of ocean environment fromremote sensing (sea surface temperature, concentration of Chl-a, sea surface salinity and sea surface height), we established a habitat suitability index model (HSI) according to different factors in different seasons, and tested different factors with differentweights and different accuracy of HSI models to determine the weight coefficients of different seasons. The results show that suitable values of environmental factors varied fromseason to season obviously. In spring, the weight coefficient of sea surface temperature was equal to 0.7 and the others were all equal to 0.1; in summer, the weight coefficient of Chl-a was equal to 1 and the others were all equal to 0; in autumn, the weight coefficient of Chl-a was equal to 0.7 and the others were all equal to 0.1; in winter, the weight coefficient of sea surface temperature was equal to 1 and the others were all equal to 0. The results suggest that the fishing grounds of Sthenoteuthis oualaniensis response differently to different environmental factors in different seasons, and the accuracy of HSI model can be improved when the factors are applied with different weight coefficients.