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Posidonia oceanica (L.) Delile is a keystone seagrass species, playing a central role in the ecological balance of Mediterranean coastal areas but threatened by increasing human pressures. Proper management and conservation of coastal marine habitats require the understanding of its distribution. To address this need, we developed habitat suitability models (HSMs), built up using the Random Forest algorithm in R software, that assess the suitability of the environment for the presence of P. oceanica in the Ligurian Sea (NW Italy).Model response variables included potential seabed areas characterized by P. oceanica habitats on soft and rocky bottoms, down to 50 m depth. Explanatory variables included natural factors as well as variables related to human activities along the coastal strip.The HSMs showed high accuracy rates of 82% for P. oceanica on soft bottom and 99% for P. oceanica on rocky bottom. The models predict an increase in P. oceanica meadows on soft bottom, from 2448 ha to 11623 ha, and a modest increase on rocky bottom, from 159 ha to 200 ha. The west coast of Liguria was found to have a greater extent of seagrass meadows compared to the east coast.This study provides valuable guidance for the sustainable management of P. oceanica meadows and offers practical tools for scientific research, land managers, stakeholders, and policy makers. These findings are essential for the conservation of a vital marine ecosystem and for promoting prudent and effective land management, ultimately securing the legacy of P. oceanica in northwestern Italy.

Coastal marine ecosystems are among the most productive ecosystems worldwide, providing essential resources both for the environment itself and for human life. This is the case of the Ligurian Sea, rich in marine biodiversity that characterizes a valuable natural capital that has, however, been damaged by the development of human activities along the coast leading to a decline of this biodiversity and health status of coastal ecosystems.This study analyzes the relationships between the distribution of natural capital and environmental flows values of Ligurian marine coastal habitats, and the natural and anthropogenic variables located along the coast. These variables may influence the capacity of the environment to generate and maintain the natural capital and affect, either directly or indirectly, positively or negatively, its spatial distribution together with that of the environmental flows. These relationships were analyzed using the Random Forest technique, subsequently compared with information from interviews administered to experts in the marine coastal field.Both methods showed that the anthropogenic variables have a greater influence on values’ distribution if compared with the natural ones, with a positive effect (namely the settlement of protection measures) showed as an increase in natural capital and environmental flows values, confirming how protection regimes (e.g., anchoring ban and establishment of Special Zones of Conservation) could be crucial for managing and conserving natural capital.This study links the status of natural capital and environmental flows along the coast to the presence of a set of variables, in order to operate on them for a better monitoring and management of the area, as well as a sustainable development.