Impact of seasonal freshwater inflow on a benthic estuarine community

Many relatively unmodified rivers of Australia are located in the tropical north and these rivers contain a large proportion of Australia's freshwater. As such, there is pressure to develop the region and plans to divert, abstract and regulate water from these rivers. Such upstream modifications are likely to impact estuaries at the receiving end of these freshwater flows. The quantity, quality and timing of freshwater, nutrients and sediments flowing into estuaries are some of the most important factors influencing the function of estuaries, including their high productivity. Estuaries in northern Australia support commercially and recreationally important fish and crustacean species as well as diverse plant and animal life. The study site of Norman river is typical of dry-tropical Australia with highly variable flows and distinct wet and dry seasons that estuarine function is likely reliant upon. It is important to understand the role freshwater inflow play in estuarine productivity under natural conditions. Therefore studies on wet-season changes to benthic meiofauna communities and primary production are underway in the Norman river estuary, one of Australia's near pristine tropical estuaries. Sampling for this study has also coincided with a one of the largest recent flooding events of the Norman River Basin.