After heavy rains in northern Queensland during February, the Burdekin River released a large plume of sediment-laden floodwater out to the midshelf Great Barrier Reef, an event which received major media coverage. In partnership with the Marine Monitoring Program, scientists from James Cook University’s TropWATER have carried out a wide variety of water quality testing on the plume under Project 2.1.5, including field sampling, sediment tracing, remote sensing and physio-chemical analysis of the water column. Usually flood plumes from the Burdekin move northwards along the inner shelf of the Great Barrier Reef, but calm surface conditions meant the sediment in this plume remained suspended in the upper parts of the water column, allowing it to extend large distances offshore. Preliminary findings from earlier surveys carried out under the project (from the 2016/2017 and 2017/2018 wet seasons) indicate that mineral particles < 20 µm associated with terrestrial organic matter travel furthest in the marine environment and hence this fraction should be the target for sediment management efforts. A technical report produced under the project has been provided to the Queensland Government’s Office of the Great Barrier Reef. Researcher Dr Zoe Bainbridge from James Cook University said “This research provides valuable information for several landscape remediation programs particularly focused in the Bowen-Broken-Bogie tributaries of the Burdekin catchment. We are able to apply this information to better target the erosion areas that are contributing the most harmful sediment to the Great Barrier Reef.”
