Published online by Cambridge University Press: 01 April 2014
Aggregates of the Polychaeta Phyllochaetopterus socialis were recorded for the first time off Gemlik Bay in the Sea of Marmara, in August 2008. These were found at about 53 m depth, on the soft sediments around the sub-sea part of the North Anatoly Earthquake Fault. Samples were landed by beam trawl. Total wet weight of the mats was 58 kg. Forty-three species belonging to 10 phyla associated with P. socialis were recorded from the whole landing materials. Echinodermata and Gastropoda were the most abundant (12 and 8 species, respectively). Shannon–Wiener diversity and Margalef species richness indices were applied to analyse the structure of benthic communities. Presence and abundance lognormal distribution of the species and communities in mat habitat are shown. The hydrographic environment of the water mass is also discussed.