The role of sedimentological information in estuary management

Th e analysis of sediment cores from estuaries can provide a range of useful insights into their environmental history and health. In many Australian estuaries the rate and nature of sedimentation has significantly changed since European settlement. Wave-dominated estuaries in particular, which act as efficient sediment traps, are more rapidly infilling. In these estuaries the deeper central basins are filling with fine sediments, while fluvial deltas are rapidly prograding into the estuary. Turbidity has also increased because of resuspension of the fine lithic and organic sediments by waves and tidal currents. Analysing cores of sediment from the various estuarine depositional environments can provide measures of the rate of sedimentation and temporal changes in the character of sediments. These data can be used to identify the physical impacts on the estuary of catchment land use practices. Sediment cores can also provide evidence of recent changes in the concentrations of nutrients and other pollutants that have entered the estuary, as well as recent changes that have occurred in estuarine vegetation communities. Clearly, this information can help inform the management of the estuarine environment.