Mega-benthic assemblages have been analyzed off Terre Adélie (East Antarctica) between 20 and 110 m depth by seabed videography. The study area is dominated by high abundances of sessile suspension feeders, however, sponges are rare at this depth. There are hints and evidence that different levels of disturbance and biological dynamics affect these assemblages. Biodiversity results are interpreted with the background of an applicability of the intermediate-disturbance hypothesis (IDH). © 2007 Springer-Verlag.