Over the last year, the Great Barrier Reef (GBR), a UNESCO World Heritage Area, has been impacted by mass coral bleaching, two cyclones, storm surges, flooding, and multiple crown of thorns outbreaks, causing significant reef damage. How best to protect and preserve this unique, biodiverse coral reef, and other reefs around the world? That is a question scientists have been grappling with.
In a recent UNESCO World Heritage Committee Report, the GBR avoided being added to the ‘List of World Heritage in Danger’ sites. At least for now. But that report warned that more needs to be done to preserve this precious ecosystem. Primarily, Australia needs to set higher climate target levels. Furthermore, it stated that the rate of land clearing in the catchments, where run off and sediment flow into the GBR, did not bode well for the future health of the GBR.
In August this year, Nature magazine reported mass coral bleaching on the Great Barrier Reef in Australia between 2016 and 2024 was driven by high sea surface temperatures. And using climate models, demonstrated how recent extreme temperatures occurred largely thanks to greenhouse gases in the atmosphere caused by burning fossil fuels. This research described it as an ‘existential threat’ to the reef, and went on to explain how, without rapid cuts to greenhouse gas emissions ‘we will likely be witness to the demise of one of the Earth’s natural wonders.’
Coral reefs are living organisms. Currently the UNESCO World Heritage List consists of 50 marine sites, with 29 of them ‘featuring coral reef ecosystems’. It is estimated that recent coral bleaching events, caused by marine heatwaves, have affected almost one third of those coral reef ecosystems spread across countries. Coral bleaching is a stress reaction to warming sea temperatures. The algae, which is the source of the coral’s colour and nutrients, is expelled, leaving the coral an eerie white.
In May, representatives from the 29 World Heritage listed reefs met online to share knowledge and experience monitoring the latest mass bleaching event. The aim was to learn from each other about bleaching alert systems and how best to be prepared to protect these ‘vital ecosystems’ when future bleaching events occur.
In Australia, a recent marine heat wave saw about 75 per cent of the GBR impacted by severe mass coral bleaching. And Scientists at the Australian Institute of Marine Science described this most recent bleaching event as the ‘most extensive and