Abstract: Research on habitat suitability of marine ranching species is crucial for optimizing co-culture schemes of functional populations and enhancing marine ecosystem sustainability. We evaluated the habitat suitability of Betaphycus gelatinae, Acropora echinata, Stichopus variegatus, Pinctada maxima, and Epinephelus coioides in Wuzhizhou Island Marine Ranch using an optimized MaxEnt model. We further identified the key environmental factors influencing species distribution and proposed functional zoning recommendations. Results showed that the area under the receiver operating characteristic curve of each model was all greater than 0.9. Water depth, nitrate concentration, pH, and current velocity were the key environmental factors affecting habitat distribution of the five species. The high-suitability areas for E. coioides were concentrated in the southern and southwestern parts of the island. The suitable areas for A. echinata exhibited a circumferential distribution pattern, particularly on the eastern and southern sides. B. gelatinium and S. variegatus showed relatively regular distribution patterns, with high-suitability areas concentrated in the northern/northeastern and northern regions, respectively. P. maxima displayed a scattered distribution without distinct spatial trends. We proposed that Wuzhizhou Island Marine Ranch should be divided into comprehensive functional zones, including: algae-coral synergy zone, coral-friendly tourism zone, natural coral reef reserve, artificial reef nursery zone, algae aquaculture economic zone, and integrated aquaculture zone. This study would provide scientific support for functional population zoning in Wuzhizhou Island Marine Ranch.

Key words: MaxEnt model, Wuzhizhou Island, marine ranching, habitat suitability, functional zoning