Habitat Suitability Model for Predicting the Occurrence of Scleractinian Cold-Water Corals in the Gulf of Naples (Tyrrhenian Sea): a Tool for Restoration Planning and Governance of Deep-Sea Ecosystems

Cold-water corals (CWCs) are key ecosystem engineers in deep-sea habitats, yet their distribution in the Gulf of Naples remains poorly known. Here, we applied a Maximum Entropy (MaxEnt) model with high-resolution environmental predictors to investigate the fine-scale suitability of scleractinian CWCs within the Gulf of Naples and adjacent areas. Presence records were derived from Remotely Operated Vehicles (ROV) video analyses, while predictors included bottom current velocity from a Regional Ocean Modeling System (ROMS) simulation and geomorphological variables from multibeam bathymetry (bathymetric position index, slope, roughness, aspect, and backscatter). The model predicted similar to 0.43 km(2) of suitable habitat (suitability index >0.6) corresponding to 0.09 % of the entire study area, mainly along canyon walls and elevated seabed features of the Dohrn Canyon. Additional suitable areas were identified in the deeper canyon sectors and south of Ischia Island. Current velocity at the bottom influenced the most our model, with high suitability values obtained from 0.10 to 0.18 m/s, suggesting these as favorable conditions for sediment removal and food supply. The variable response curves documented that Bathymetric position index and roughness contributed to the model, with preferences for elevated seabed features and heterogeneous seafloor topography. These findings highlight the role of bottom current velocity and topographic complexity in shaping CWCs habitats in the study region and reveal unexplored areas with high potential for coral occurrence. Model outputs provide a scientific basis for Natura 2000 site designation and support conservation and restoration strategies for vulnerable deep-sea ecosystems in the area.