Distribution of the deep-dwelling gorgonian Viminella flagellum in the Italian western Mediterranean Sea by means of multi-year ROV surveys

The whip-like gorgonian Viminella flagellum (Alcyonacea, Ellisellidae) is an Atlantic-Mediterranean species living in temperate and subtropical waters. Past knowledge about species occurrence in the Mediterranean Sea was limited to the surrounding of Gibraltar Strait and the Balearic Sea. A multi-year ROV video surveys allowed updating the distribution of this species in the Italian waters and obtaining information about its occurrence, abundance and associated species. V. flagellum dwelled in rocky environments at 100-250 m depth, from the Ligurian Sea to the Sicily Channel. It may form very dense monospecific meadows or show a sparse distribution associated with highly diversified coral benthic assemblages, forming a so called “coral garden”. The availability of appropriate technical devices allowed us to obtain more specific information about this species and its distribution. The high species richness of the assemblages hosting V. flagellum, together with their vulnerability to human activities, should motivate the adoption of conservation measure for these deep environments.