Two aquatic bioregions proposed for the South Coast Region,Western Australia

摘要

A need for the development of a bioregionalisation for Australian rivers using aquatic fauna hasbeen recognised. This study was aimed at delineating and describing interim aquatic bioregionsfor the South Coast region in Western Australia. Macroinvertebrates were collected from 33waterways located across the region, and data were analysed using cluster analysis. Two broadaquatic bioregions were identified, the Western South Coast bioregion, consisting of rivers lyingfrom Gardner River in the west to the Bluff River, and the Eastern South Coast bioregion, consistingof the Pallinup River through to the Thomas River in the east. Rivers located in the latter bioregionwere significantly more saline, slightly more alkaline, and had higher levels of total nitrogen thanthose located in the Western South Coast bioregion. Many species proved significant indistinguishing the two bioregions. The successful implementation of a biotic classification methodto delineate aquatic bioregions for the South Coast Region indicates that the approach may beeasily instituted and adapted for other regions within Western Australia, and could be undertakenusing macroinvertebrate data generated by past sampling programs.