Scientists are warning of devastating coral bleaching on the Great Barrier Reef, off the coast of Australia's eastern state of Queensland.
According to the local non-governmental organization Climate Council, new underwater images show the full extent of the disaster. An area 1,100 kilometres long from Lizard Island to the Keppel Islands has already been affected, the Australian news agency AAP reported on Tuesday.
According to experts, the trigger is a recent marine heatwave in the region.
Diana Kleine, a project manager for the environmental monitoring group CoralWatch, has been visiting the Heron Island research station in the southern part of the Barrier Reef for 25 years and says it is the worst bleaching event she has seen.
"Heron Island has luckily escaped several bleaching events in the last couple of years but the way it is looking now is just devastating," she told AAP.
The island lies around 460 kilometres north of Brisbane in the area affected by the current bleaching event.
The Great Barrier Reef is increasingly under threat due to global warming. In difficult conditions, the corals repel the algae responsible for their colouring, with which they normally live together in a symbiotic relationship.
Bleached corals, cnidaria, are extremely stressed, but they are still alive and can recover. According to experts, however, the extremely warm seawater makes them susceptible to diseases that can kill them.
If the water does not cool down in the coming weeks, it is only a matter of time before the bleached cnidarians die off, said Kleine.
With water temperatures of up to 30 degrees Celsius, up to 80% of the coral is bleached in some places.
