Biodiversity assessment of Kaynak Sa Cave (Mersin, Türkiye): a baseline study for the conservation of eastern mediterranean marine cave ecosystems

Sea caves are exceptional yet highly vulnerable marine habitats, harboring rich and specialized biodiversity. Recognized as priority habitats under the EU Habitats Directive (92/43/EEC) and the Barcelona Convention, they play a critical role in supporting unique species assemblages. Despite their ecological importance and widespread presence throughout the Mediterranean, quantitative data on the biodiversity and ecological functioning of sea caves particularly in the Eastern Mediterranean remain scarce. This study aims to document the biodiversity of Kaynak Sea Cave, located in the Aydıncık district of Mersin (Türkiye), and to contribute to a scientific framework for the conservation of sensitive species and key habitats in the region. Biodiversity assessments were conducted through scuba diving surveys and photographic documentation by experienced divers. A total of 119 species belonging to 12 major taxonomic groups (Phaeophyceae, Rhodophyta, Chlorophyta, Porifera, Cnidaria, Polychaeta, Crustacea, Mollusca, Bryozoa, Echinodermata, Tunicata, Pisces) were identified from photographic records. However, it is presumed that the actual species richness is significantly higher. This baseline inventory underscores the ecological value of Kaynak Cave and highlights the need for future comprehensive studies focusing on cryptic fauna, soft-bottom habitats, and seasonal-spatial dynamics of benthic communities.