Spatial and Temporal Distribution of Habitat Pattern of Trichiurus japonicus in the Northern South China Sea Under Future Climate Scenarios

The impact of climate change on fish distribution has drawn increasing attention worldwide. Studying the distribution patterns and habitat evolution trends of largehead hairtail (Trichiurus japonicus), an important fishery resource in the northern South China Sea (NSCS), is of great significance for the management and sustainable utilization of fishery resources. This study uses an ensemble species distribution model to analyze the seasonal distribution patterns of T. japonicus in the NSCS and predict the changes in highly suitable habitats of T. japonicus under four future climate scenarios (IPCC Shared Socioeconomic Pathways SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5). The results show that the area of suitable habitats in the Beibu Gulf is expected to increase, while that in the offshore of Guangdong will significantly decrease. In different seasons, there are differences in environmental factors affecting the distribution of T. japonicus, among which sea bottom temperature (SBT) and bathymetry (BM) are key factors. Under the SSP1-2.6 scenario, the area of highly suitable habitats for T. japonicus is expected to decrease by 30.54% by the 2100s, while under the SSP5-8.5 scenario, it is expected to decrease by 53.67%. Our research results show that the active range of T. japonicus in the NSCS has different adaptive responses to different climate change scenarios, which has an important impact on the development and management of T. japonicus resources.