Difference in seasonal shift of spatial homogenization between taxonomic and functional structure in demersal fish communities

Under climate change and anthropogenic activities, the homogenization of fish communities shows spatial and temporal shifts and threatens biodiversity and ecosystem functioning, but little effort has been made to assess the seasonal shift of spatial homogenization in marine demersal fish, which hinders effective management. In the present study, we investigated the spatial patterns of demersal fish communities and their seasonal changes in the shelf sea of Shandong Peninsula in northeast China based on the four seasonal surveys. Our findings showed that both season and region were important factors in the distributions of biodiversity and the community structure of demersal fish. Spatial homogenization of taxonomic structure and functional structure exhibited inconsistent changes with season. Compared with taxonomic structure, functional structure exhibited relatively lower spatial homogenization in all seasons. Our results suggest that the density of survey stations for demersal fish resource investigation in the study area should be conducted in at least four regions and considering seasonality. This study highlights a need to understand spatial homogenization and its seasonal changes in demersal fish in both taxonomic and functional approaches, which could give insight into biodiversity and resource state and be conducive to improving the efficiency of resource investigation and management.