Tracing of Materials from the Upper Catchment to the Reef
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The CRRG uses the physical, elemental and isotopic makeup of soils/suspended sediments in the Burdekin River catchment to obtain a distinct “fingerprint” of the fine sediments (mud fraction) entering the marine environment. The key aims are to examine which soil types contribute to the total suspended sediment load from the Burdekin River and to identify specific sources of the fine sediments which are transported large distances in the GBR lagoon.
In addition, we have studied the sediment trapping efficiency of the Burdekin Falls Dam, over several wet seasons, to examine siltation within the dam reservoir and to construct detailed ‘bulk’ suspended sediment export budgets for the Burdekin River. These studies will help to prioritise on-ground management actions within the catchments of the Burdekin Region, aimed at reducing rates of soil loss.
Our group has also used coral core records to investigate temporal changes in the delivery of sediments and nutrients from catchments of the GBR. Trace element and isotopic changes in the skeletal growth of massive long-lived corals can provide a means to quantify changes in suspended sediment and nutrient runoff, and help to establish a pre-European ‘baseline’ for Water Quality Improvement Plan (WQIP) target setting exercises for end-of-river loads.