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

Abstract

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. tha-zard 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.