Widespread Coral Mortality Associated With River Flood Discharge In Great Barrier Reef

Heavy rainfall has been occurring in northern Queensland since December causing widespread flooding of coastal rivers (Burdekin, Haughton, Bohle, Herbert, Tully, O’Connell and others) as well as inland catchments. In some places all-time records were broken, especially around Townsville, and the flows in the Herbert and Burdekin were both far above average (more rain may occur as well).

The river discharge events are being tracked by satellite imagery in collaboration with Arnold Dekker’s group, CSIRO, Canberra and Lachlan McKinna in Michelle Devlin’s flood plume project at JCU. The plumes are noticeable as sediment rich in the early stages (January - image1) and extending out to near Dunk Island but colour rich (chlorophyll and coloured dissolved organic matter) in the latter stages (February - image 2) extending completely across the main reef and into the Coral Sea.

The plumes are being sampled via the GBRMPA – Reef and Rainforest Research Centre, Marine Monitoring Program run by the Catchment to Reef Group, ACTFR, JCU (Michelle Devlin coordinator) and AIMS (Britta Schaffelke). Sampling from both fixed installations and vessel surveys have been going since December.