MICRO-INVERTEBRATE COMMUNITY STRUCTURE WITHIN A MARITIME ANTARCTIC LAKE (Eleventh Symposium on Polar Biology)

The data set discussed here was obtained from a transect across a depth profile in Sombre Lake (Signy Island, South Orkney Islands). The fauna, composed of benthonic micro-invertebrates, was readily observed grazing on the surface of the cyanobacterial mats that form a thin cover on the surface of the sediments. Algal mat composition varied in response to factors such as light, climate, and ice scour. Micro-invertebrate species diversity was limited, but population numbers were high. The results indicated a degree of substrate selectivity by the invertebrate community as illustrated by the distribution of tardigrades-a major component of the faunal community. Comparison is made between samples, collected at the same time, which were either examined fresh or preserved by freezing then thawed for examination in the U.K.