Modelling the Spatial Distribution and Habitat Preferences of Three Caspian Endangered Sturgeons Species Using MaxEnt

Sustainable preservation and management of sturgeon habitats in the Caspian Sea (CS) require sound knowledge of habitat suitability (HS). Here, the MaxEnt model was applied to map the HS and distribution of HS of Acipenser persicus , Acipenser stellatus and Acipenser gueldenstaedtii using 11 environmental variables. The model showed high predictive performance, with training AUC values exceeding 0.91 and TSS above 0.70 for all species. The most powerful environmental drivers were sea surface salinity (SSS), particulate inorganic carbon (PIC) and water depth, although their impact varied somewhat among species. Geographical analysis indicated that A. persicus and A. stellatus had higher HS in the southern CS, while A. gueldenstaedtii was more associated with the northern CS. The middle CS exhibited low HS for three species. Relative proportions of highly suitable habitats were less than 1.5% for all species, whereas moderate suitability was 65.6%, 63.7% and 62.7% for A. persicus , A. stellatus and A. gueldenstaedtii , respectively. Climate change exacerbates rising sea surface temperatures (SSTs) and low water levels, which severely threaten sturgeon populations, especially in the shallow northern regions. Habitat loss and poaching also endanger these species, and region‐specific conservation efforts are strained. The findings highlight the need for targeted management of sturgeon in the CS. Conservation efforts should prioritize the southern CS as a key HS area for A. persicus and A. stellatus and the shallow northern area for A. gueldenstaedtii . Combined with transboundary cooperation and effective fisheries regulations, these measures are vital for the sustainable conservation of each species.