Preliminary ROV surveys data on deep-coral assemblages from South-East Sardinian Sea (central western Mediterranean)

Deep-sea habitats have a high conservation interest since they often host greater diversity than surrounding areas as well as unique assemblages. Within a deep-sea research cruise aimed to monitor the presence of the resource from circa-littoral to down to the upper bathyal zone (from100 to 300 meters), the occurrence of the most representative coral species was observed. The cruise was carried out on board the ISPRA’s R/V Astrea in the Southeastern waters of Sardinian (Central-Western Mediterranean) during Autumn 2011 by means of Remotely Operated Vehicle (ROV Seaeye Falcon by Saab). Biological data were collected combining large and fine scale Multibeam dataset and ROV imaging. Three heads of canyons located inside the Marine Protected Area of Capo Carbonara were investigated and species belonging to three main orders (gorgonians, alcyonaceans and antipatharian) were recorded to characterize those rocky habitats. The results, in terms of occurrence and abundance of the main species are presented, considering these cnidarians as valid surrogate descriptors of megabenthic marine biodiversity due to their richness, abundance and identification easiness. Among gorgonians, few banks of both living and dead red coral were documented. Also the presence of discarded fishing gear and other kind of anthropic debris has been recorded, showing how these environments are potentially threatened by human activities. Given the rarity of fine-scale in situ direct observations, the present study aims to describe preliminary data on deep-sea corals diversity in a poorly investigated area in the heart of the Mediterranean Sea, representing an important contribution in filling the existing gaps in knowledge