Taxonomy of estuarine invertebrates in Australia

An Australian estuary is primarily a marine-dominated environment, subjecte d to major salinity changes only after heavy rains and during flood conditi ons. In southeastern Australia estuarine biota are similar to those in shal low coastal bays and some of the coastal lagoons, and most taxonomic studie s on estuarine fauna have occurred in this region. Several major surveys of estuarine and coastal bays have been undertaken in Australia during the pa st three decades and these surveys have largely provided the material for t axonomic studies of the major groups of macrobenthos. All these studies hav e revealed a diverse and abundant benthic macrobenthos. The composition of estuarine invertebrate fauna is compared with open exposed coasts, includin g fauna found in soft strata and on hard strata. Australia has a limited sp ecialized estuarine biota much of which is restricted to particular habitat s, and a highly diverse marine community which thrives in the sheltered pro tected waters of estuaries and the associated soft sediments. Currently, in teractive computer-based keys are being developed which should greatly assi st the student and the benthic ecologist to identify the fauna and prevent potential loss of data. Some aspects of the current debate of the level of taxonomic resolution required to answer various ecological questions are di scussed. Finally, some comments are suggested as to future directions in wh ich taxonomists and estuarine ecologists should proceed in order to be able to detect changes or losses of estuarine biodiversity and the loss of the associated biological information which may be critical in understanding th e functioning of the estuarine ecosystem.