Cold-water coral habitat in the Bari Canyon System, Southern Adriatic Sea (Mediterranean Sea)

Abstract The Bari Canyon System (BCS) is located on the southwestern Adriatic margin, in the Central Mediterranean Sea indenting the continental shelf at approximately 200 m. It is characterized by a rough morphology, with two main parallel branches and a channel–levee complex with subvertical flanks, and a variable substrate with rocky outcrops along the canyon flanks. The geological context and the presence of two different dense water masses, the Levantine Intermediate Water (flowing along slope) and the North Adriatic Dense Water (cascading down slope), impacting the canyon act as major drivers for the settlement of valuable biota, such as cold-water corals (CWC), among which Madrepora oculata is the main frame builder. Due to the relevance of its CWC habitat, the BCS has been explored since 2003 by several oceanographic cruises and a huge amount of multidisciplinary data (e.g., geophysical data, sediment samples, ROV images, CTD and mooring deployments) was collected to map the BCS habitat at different scales with different methodologies. The abiotic and biotic components of the BCS benthic habitats were manually mapped and classified, applying a hierarchical scheme (CoCoNet classification scheme) to categorize and integrate at different scales every habitat component to obtain a comprehensive view of the benthoscape. The CWC habitat mapping was also supported by habitat suitability models implemented for the BCS (Ecological Niche Factor Analysis, Maximum Entropy—Maxent; Generalized Linear Models), to infer the habitat extent within the canyon.