[Potential marine habitat suitability of Acipenser sinensis based on the MaxEnt model]

As a flagship species in marine, the conservation of Acipenser sinensis habitat is of great significance for biodiversity maintenance. Based on 339 records of A. sinensis bycatch in the ocean and related environmental data from 2022 to 2023, we investigated its distribution characteristics and habitat selection using the MaxEnt model. The results showed that A. sinensis was primarily distributed in the waters of Hangzhou Bay and the Xiangshan area, with a relatively broad range in spring and winter, while the distribution was more concentrated in summer and autumn. The MaxEnt model revealed that key environmental factors influencing the potential habitat of A. sinensis were bottom water temperature, silicate concentration, and pH. When the temperature of bottom water ranged between 19-23 ℃, the silicate concentration exceeded 15 mmol·m^-3, and pH was between 8.2 and 8.5, the probability of A. sinensis presence was higher. Within the study area, the highly suitable zone covered an area of 258.71 km² (6.9% of the total), while the suboptimally suitable zone spanned 703.46 km² (18.7%). The main highly suitable zones were located in the waters of Hangzhou Bay, the Xiangshan Port-Jiushan Archipelago-Sanmen Bay-Jiaojiang area, while the suboptimally suitable zones were primarily found in the waters near Zhoushan-Ningbo-Taizhou to the east and south, as well as the coastal waters of Jiangsu.