Today the Australian Institute of Marine Science released the annual update from its Long-Term Monitoring Program.
It is extremely encouraging to see the headline Reef health indicator – coral cover – has continued to recover in the northern and central Reef. However, coral cover in the south has declined slightly, primarily driven by predation from crown-of-thorns starfish (COTS), highlighting the importance of our ongoing COTS control program.
This period of recovery is driven by the absence of major cyclones and reduced COTS predation in the northern and central regions, which has aided this improvement in coral cover. The last major coral mortality event was a marine heatwave in 2017. While last summer's and the 2020 heatwave caused extensive bleaching across the Reef, surveys to date indicate the intensity of the bleaching did not cause significant coral mortality.
This resilience is very encouraging and reaffirms the Reef Authority's focus on protecting Reef health, particularly through our Marine Park zoning and crown-of-thorns starfish control program – critical in the face of growing impacts from climate change. However, the recovery in coral cover is being driven by fast growing corals that are sensitive to thermal stress, fragile to storm damage, and are the preferred food species of crown-of-thorns starfish. Therefore, this recovery is delicate, and can easily be set back by future impacts, particularly from extreme weather events driven by ongoing climate change.
The resilience demonstrated by the Reef in the recent period of heatwave conditions represents an opportunity to improve its outlook. The strongest possible action to reduce greenhouse gas emissions globally and constrain further climate change, coupled with our local work to protect the Reef, are essential to securing a healthy and resilient Great Barrier Reef into the future.
