Geostatistics-based study on spatial-temporal distribution of Auxis thazard in South China Sea

In order to study the spatial-temporal distribution characteristics of Auxis thazard, we analyzed the spatial-temporal distribution characteristics and ecological dynamics of Auxis thazard by geostatistical methods based on the data from the light falling-net fishery survey conducted in the South China Sea from 2016 to 2017. The results show that the distribution of A. thazard in the South China Sea was of mainly low-density, and there were few high-density sea areas. The seasonal aggregation characteristics of A. thazard in the offshore shallow waters were obvious, and the resource density index followed a descending order of summer>spring>autumn. The spatial distribution of A. thazard fishery had strong spatial heterogeneity, with the proportion of spatial structure over 75% in the four voyages. The spherical model was the main variation model, and the average main variation range was 1.861 0°. The A. thazard in the South China Sea was obviously characterized by southwest-northeast migration, and its spatial layout had a patch-like spatial distribution. The results can better reflect the spatial-temporal distribution characteristics of the A. thazard fishery in the South China Sea, which provides a scientific basis for its fishery analysis and management.