Analysis of the meta structure community of macrobenthos bottom soft in Admiralty Bay, Bransfield Strait and around the Elephant Island

Abstract

We obtained estimates of abundance and benthic biomass, in six stations between 40 - 510 m of depth in Admiralty Bay (AB); two stations at 65 and 115 m around Elephant Island (EI) and a station at 96 m depth off Astrolabe Island (AI). Every effort was made in AB, characterized by slightly compact silty mud sediment and with great content of stones. Nucleus of abundance exceeding 4 000 ind.m-2 are observed to less than 400 m; different the biomass recorded maximum values at greater depths. Both AB and AI, numerically dominated Polychaeta (67%) and Amphipoda (12%). In biomass inside AB highlighted the Mollusca Bivalvia (34%), Sipuncula (27%) and Polychaeta (23%). Around EI deep station recorded the greatest diversity, characterized by 90% by the Polychaeta. Important is the contribution of Porifera opposite the Station Scientific Antarctic Machu Picchu (ECAMP). Other frequent groups were Echinodermata Asteroidea (AB), relevant Ofiuroidea on biomass in the E12 (AI) and dominant Holothuroidea in A1. Class Ascidiacea as Porifera, were represented by solitary species, some large (F and E12). Small Cnidaria-Actiniaria were observed in AB with low abundance and biomass. Four classes represented numerically smaller mollusk: Gastropod, Bivalvia, Polyplacophora and Scaphopoda.