Quantitative assessment of benthic fauna and assemblages in the Heard Island and McDonald Islands region

A benthic sampling program in the Heard Island and McDonald Islands (HIMI, CCAMLR Statistical Division 58.5.2) region was undertaken by the Australian Antarctic Division (AAD) from 2003 to 2008. Quantitative samples collected during three cruises by the fishing vessel Southern Champion from eleven geographic areas, using either a beam trawl or benthic sled, provide the most comprehensive quantitative insight into the distribution, abundance and species composition of macrobenthic invertebrate communities in the region. The areas sampled were selected for the purpose of comparing and reporting regional differences in faunal composition and consist of a number of seamounts and submarine plateaus. The macrobenthic invertebrate fauna of the region is moderate in diversity and, while many taxa are endemic, is broadly typical of deep sea sub-Antarctic faunal assemblages. Included in these taxa are a range of slow growing and vulnerable benthos, including corals, sponges and bryozoans, which would be particularly susceptible to disturbance. The results of this assessment are being used by Australia in evaluating the conservation of benthic biodiversity in this region.