Shallow benthic fauna communities of South Georgia Island

摘要

Benthic communities in several fjords and sheltered bays of the north coast of South Georgia Island were examined using SCUBA and shore sampling in November 2004. It is one of the most northerly islands within the Polar Front and its well studied, terrestrial biota is described as sub Antarctic. The intertidal and subtidal zones and their fauna are, by comparison, little known. We describe the composition of the substratum and benthic communities of sites in several northern bays, including an exceptional community in the extremely sheltered Moraine Fjord with a 2 m sill at its entrance. In this, like those in some other fjordic systems, some taxa occur shallower than elsewhere, and in this instance, get large and are probably old. Elsewhere, we found the coastal fauna was fairly similar to Antarctic shallow communities in the southern Scotia Arc and Peninsula region. Of the taxa we found, we identified 53 to genus and 41 to species. Most of these were typical Antarctic shallow benthic taxa. Certain flatworms, nemerteans, bivalve and gastropod molluscs, amphipod and isopod crustaceans, asteroid echinoderms and stalked ascidians were very abundant, but some normally common Antarctic higher taxa and species were notably absent or rare.