The estuaries of Australia’s tropical rivers support commercial fisheries for finfish and shellfish valued at over $220 million per annum. There are also significant tourism-related and local recreational and indigenous fisheries for icon species such as barramundi. Development of water resources in Australia’s Tropical Rivers region is being considered for the Flinders, Mitchell, McArthur, Roper, Daly and Victoria catchments. Greater knowledge of the freshwater requirements of tropical aquatic ecosystems, including estuaries is crucial, so that the communities of catchments where water resource development occurs can be assured that the downstream effects of such development are considered and managed based on the best available knowledge.
Most research into the role of freshwater flows in aquatic ecosystems that support fish and fisheries has occurred in freshwater reaches of southern Australian rivers, except for that in the Fitzroy River Queensland, (a large dry tropical river). Conceptual models of the role of freshwater in estuaries of the Gulf of Carpentaria (GoC) and the effects on estuarine-dependent fisheries (i.e., LWA project QP155) is based on available knowledge gained from research in the Fitzroy River. However, these conceptual models lack confirmation of the underlying mechanisms, mostly as a consequence of a lack of process understanding as it occurs in GoC estuaries.

Greater knowledge of the role of freshwater flow in estuarine-dependent fisheries production in the GoC will allow for informed sustainable development of tropical water resources, with minimal impacts on fisheries resources.