The Structure of the Littoral Invertebrate Communities of the Kosciuszko Region Lakes

Abstract

The littoral macroinvertebrate assemblages of Lakes Albina, Blue, Club andCootapatamba in the Mt. Kosciuszko region were sampled by two methods: sweeps and cobble picks. Thirty-six species were collected with total abundance and species richness greatest in Lake Albina. Common species included themolluscs Pisidium kosciusko and Glacidorbis hedleyi, the crustaceans Metaphreatoicus australis and Neoniphragus n. sp., and an unidentified limnephidtrichoperan. Community structure was influenced by the nature of the substrate, with cobble sites having greater richness and abundance than boulder sites. The importance of the major taxonomic groups (crustaceans, insects and molluscs) varied with sampling method and among lakes. Crustaceans (isopods and amphipods) usually dominated in sweeps, with molluscs and insects varying in importance among lakes, while insects mostly dominated in cobble pick samples. Oligotrophic lakes are typically thought to be dominated by insects, however this study shows such lakes may appear to be dominated by insects or crustaceans depending on the sampling method used and the presence of fish.