Macrobenthic communities on the continental shelf of the Prydz Bay, East Antarctica

To explore the spatial pattern of macrobenthic communities and their response to environmental factors in the Prydz Bay, samples were collected using a 0.25-m2 box corer at 10 stations from November 2012 to April 2013. A total of 50 species of macrobenthos belonging to 8 phyla and 33 families were identified, of which polychaetes(e.g., Maldane sarsi) and sponges(e.g., Halichondria sp. and Leucosolenia sp.) were the most prominent groups.The macrobenthos in study area were categorized into five functional groups based on the feeding type, and the detritivorous group represented by polychaetes showed the highest average abundance, while the planktophagous group represented by sponges showed the highest average biomass. Macrobenthos abundance(0–592 ind./m2) and biomass(0–1 155.5 g/m2) in the Prydz Bay were relatively lower than those of other Antarctic shelf soft-bottom waters, although the compositions of the dominant species and functional feeding groups were similar. The results of the Spearman rank correlation analysis indicated that the average biomass of the macrobenthos and the biomass of the planktophagous group in the study area were negatively correlated with the water depth, sediment grain size and silt percentage. However, these variables were clearly not strong determinants of macrobenthos assemblage structure. Many factors not measured in the study, e.g., sediment organic matter and iceberg interference, have probably influenced the spatial distribution of macrobenthic community structure in the Prydz Bay.