Effects of spatiotemporal and environmental factors on the fishing ground of Trachurus murphyi in Southeast Pacific Ocean based on generalized additive model.

Based on the 2001-2007 Chilean jack mackerel (Trachurus murphyi) face data from Chinese vessels, as well as the spatioemporal factors and the environmental factors such as sea surface temperature (SST), chlorophyll concentration, and temperature gradient (TGR) in the South-east Pacific Ocean, this paper analyzed the resource variation of T. murphyi and its relationships with the spatiotemporal and environmental factor in the Ocean by using generalized additive model (GAM). The results showed that the rate of deviance explained about CPUE (catch per unit mainly concentrated in the 17th-41st weeks of the year, with the CPUE reached the highest in the 25th - 31st weeks. The fishing ground of T. murphyi in the Ocean was mainly located in the waters of 78° - 98° W and 30° -43.5° S. The suitable sea surface temperature was in the range of 12 °C-18 °C, and the optimum temperature was 14 °C-16 °C. The appropriate chlorophyll concentration range and temperature gradient were 0.90-0. 18 mg · ,m^-3 and 0.3 °-1.9 °C, respectively. The result s of stepwise GAM showed that the relative importance of the seven variables affecting the CPUE of T. murphyi was in the order of : weeks of the year, year, sea surface temperature, longitude, latitude, chlorophyll concentration, and temperature gradient. [ABSTRACT FROM AUTHOR]