Abstract

Scientific information on the abundance and biomass structure of shallow Antarctic coastal macrozoobenthos remains limited for many regions of the Antarctic Peninsula, particularly in shallow nearshore habitats where quantitative data are still scarce. The aim of this study was to characterise macrobenthic communities from shallow coastal habitats around South Bay (Livingston Island) and Marguerite Bay (Dismal and Horseshoe islands), with emphasis on the relative contribution of dominant higher taxa across different substrate types. In both study areas, macrozoobenthic communities were dominated in abundance by mobile crustacean taxa, mainly Amphipoda, while biomass was controlled by a small number of large-bodied taxa. At Livingston Island, biomass was strongly dominated by Bivalvia, while communities from Marguerite Bay exhibited a more even distribution of biomass among major taxa. Differences between the two areas were mainly expressed in the relative contribution of dominant taxa (Amphipoda, Bivalvia, Annelida, and Isopoda) rather than in overall taxonomic composition. In conclusion, the results clearly demonstrate a decoupling between abundance and biomass in shallow Antarctic coastal macrozoobenthic communities, and provide new quantitative data from poorly studied coastal regions of the Antarctic Peninsula.