Biodiversity of marine sessile epifauna at an Aegean island subject to hydrothermal activity: Milos, eastern Mediterranean Sea

Sessile macroepifauna was sampled at six rocky sites between 2 and 90 m dep th with a number of different methods involving both underwater photography and collection of specimens. A total of 212 species (or varieties) were id entified, belonging to seven higher taxa: poriferans (24 species), cnidaria ns (32), molluscs (8), serpuloidean polychaetes (33), bryozoans (90), brach iopods (4) and ascidians (21). The combined use of a varied array of sampli ng methods was effective in obtaining a rich faunal inventory. Deep and off shore sites tended to be richer in species than shallow and inshore sites. In all cases species richness was higher at sites closest to hydrothermal v ents on the sea floor. Although there are no comparable inventories of mari ne sessile epifauna in the Aegean, the high number of species found, with a relatively low sampling effort in a restricted area, indicates that the ma rine biodiversity of this sea is not as low as traditionally believed.