Understanding the effects of climate and anthropogenic stresses on distribution variability of Setipinna taty in the Yellow Sea

Abstract

Setipinna taty is one of the pivotal fishes in the Yellow Sea large marine ecosystem, and detecting and analyzing changes in the patterns of its distribution under multiple stresses is important in understanding its population dynamics and potential shifts in its ecological role. In this study, eight alternative spatio-temporal models were developed for S. taty using the Vector Autoregressive Spatio-Temporal (VAST) framework to analyse winter trawl survey data in the Yellow Sea from 2001–2021. These models included different combinations of local sea temperature, climate index and fishing pressure as explanatory variables. The model selected, based on Akaike's Information Criterion (AIC) and spatio-temporal variation explanation rate, indicated that the spatio-temporal distribution patterns of the population were driven by a combination of local temperature, climatic pressure, and fishing intensity. Among these factors, sea temperature is purportedly the most important driver. Results from the chosen model showed that the effective area occupied by the population decreased significantly during the study period (p<0.05). Prior to 2010, the climate and marine environment were relatively stable, and distribution changes were consistent with the basin model (BM, supported by density-dependent habitat selection theory), that individuals move to preferred habitats as biomass declines under fishing pressure (i.e. S. taty individuals were concentrated within the core distribution area as biomass declines). The climate and its driving oceanographic conditions (temperature) changed significantly after 2010 and, as a result, population distribution changes became complex (non-significant relationship between abundance and distribution area) and were no longer supported by BM, corresponding to a significant northward shift of the center of gravity (p<0.05) and a northward expansion of the northern population boundary. Our study highlights the synergistic drive of multiple stresses on spatio-temporal distribution patterns of the S. taty population. Future research should focus on developing a mechanistic understanding of the synergies between climate and anthropogenic stresses and how they affect population dynamics (distribution patterns), which is key to the successful management of the S. taty fishery and other fisheries in this ecosystem.