Laying the Foundation for Future Assessments: Preliminary Investigation of Benthic Biodiversity in a Mediterranean Marine Cave

Knowledge of biological communities in marine caves is necessary to assess possible changes over time, as they are considered vulnerable habitats threatened by multiple global and local disturbances. This preliminary study investigated for the first time the benthic assemblages of a semi-submerged marine cave in the Southern Adriatic Sea, named Sirene Cave. Overall, 67 taxa were recorded. The reduction of species richness was significantly correlated with the distance from the entrance. A growth form (GF) and a trophic guild (TG) were assigned to each taxon, which provided information on the structure and function of the cave ecosystem, respectively. The most common GF was indeterminate sheet (IS), mainly comprising encrusting sponges. The trophic guilds were mostly represented by filter feeders, with active pumping sponges (APS) being the dominant group. The Sirene Cave is located in an area rich in marine cavities, yet their benthic communities remain largely unexplored. Understanding these communities is crucial for establishing a foundation for the monitoring and conservation of this precious and vulnerable habitat.