Effects of Vertical Water Column Temperature on Distribution of Juvenile Tuna Species in the South China Sea

In this study, we conducted two surveys in the central and southern parts of South China Sea, autumn 2012 spring 2013. Six juvenile tuna species were caught each survey. Gradient forest analysis (GFA) a generalized additive model (GAM) used to analyze relationship between catch per unit effort (CPUE) for six sea temperature indices Sea. GFA, difference surface 50 m depth (D50) showed highest importance CPUE than other indices, which indicates that D50 was best predictor abundance species. The GAM lower deep-water temperature, shallow mixed layer depth, higher deeper water associated with increased CPUE. results indicate relatively rapid decrease vertical is favorable aggregation tuna. These contribute understanding distribution mechanism Sea provide scientific basis rational development utilization resources.