Transport, retention and transformation of material in Australian estuaries

Australian estuaries can be classified into five groups on the basis of the ir hydrology: Mediterranean, Temperate, Transitional, Arid Tropical and Sub tropical, and Wet and Dry Tropical and Subtropical. Most Australian estuari es (68%) are wet and dry tropical and subtropical systems. The five groups of estuaries found in Australia are similar to those found in other parts o f the world, but within each individual category the estuaries are more var iable. This variability reflects a combination of the extreme hydrology of Australian rivers and the geomorphology of Australian estuaries, which are shallow due to tectonic stability and low coastal relief. Episodic freshwat er flows control the transport, retention, and transformation of material i n most Australian estuaries, and for only a small part of the year during h igh flow events do most Australian rivers and estuaries contribute a signif icant amount of material to the continental shelf. Research and monitoring efforts need to be directed toward evaluating the role episodic freshwater discharges play in the functioning of Australia's estuaries.