The ecology of sewage treatment gradients in relation to their use by waterbirds

Abstract

The distribution and abundance of waterbirds along sewage treatment gradients at the Western Treatment Plant (Victoria, Australia) were studied in late summer/early autumn 2000. In general, the highest densities and diversity of waterbirds, and of zooplankton, were found in the ponds towards the end of a treatment series. Filter-feeding waterfowl (Anatidae) probably used these ponds because of the availability of zooplankton as a food-source. Dissolved oxygen concentration generally increased along the treatment gradient and un-ionised sulphide concentration decreased, and it is possible that either one, or both, of these played a key role in determining the distribution of zooplankton. © 2005 Springer.