Remote Sensing Of Environmental Effect On The Spatiotemporal Distribution Of Light Falling-net Fishing Ground In Beibu Gulf

Relationship of spatiotemporal distribution of light falling-net fishing ground and marine environments was analyzed in Beibu Gulf,based on generalized linear model?GLM?,generalized additive model?GAM?,multiple linear regression,fishing ground gravity,and spatiotemporal analysis,using light falling-net survey data and satellite remote sensing data?Sea Surface Wind?SSW?,Sea Surface Temperature?SST?,Chlorophyll a concentration?Chl a?,Net Primary Productivity?NPP??.Major conclusions were as follows:?1?The study of the relationship between light falling-net fishing ground and marine environments showed SST decreased gradually with the increase of SSW,and SST decreased significantly when SSW was more than 6m/s in Beibu Gulf.There was a negative correlation between SST and Chl a in Beibu Gulf in autumn and winter.The AIC value of the model decreased when SST was added into the GLM model,and in the optimal model,the relative importance of SST accounted for 72.5%.Results showed the optimum SST and Chl a of light falling-net fishing ground in Beibu Gulf were 27-29?and 0.5-1.5 mg/m³,respectively.?2?The study of the spatiotemporal distribution of light falling-net fishing ground showed SCPUE increased first and then decreased from September to December.Higher stock density appeared in the first and middle ten-day of October,and distributed in the area of 17°-19°N and 20°-21°N.?3?The results of environmental effects on the distribution of light falling-net fishing ground in Beibu Gulf showed that accumulation of deviance explained rate of SCPUE was 40.6%.The stepwise GAM indicated that the most factor was SST,with contribution being 14.3%,followed by latitude?9.5%?,Chl a?7.8%?,month?6.7%?and NPP?2.3%?.GAM model results showed the light falling-net fishing ground located in the 18.5°N and 20-20.25°N,which was consistent with the change of gravity of fishing ground.?4?Frequency distribution of SCPUE results showed SCPUE mainly distributed between 300-2000 mg·m^-2·d^-1 of NPP from September to December.From September to December,the suitable NPP for SCPUE is300-500 mg·m^-2·d^-1,500 mg·m^-2·d^-1,600 mg·m^-2·d^-1,900 mg·m^-2·d^-1,respectively.Based on the above analysis,the average longitude and latitude of the most suitable NPP for SCPUE was estimated every month,and the comparison with longitude and latitude center of gravity of SCPUE was analyzed,which had a high correlation.The longitude correlation coefficient of the two was 0.72,and the latitude correlation coefficient was 0.91.