Coral bleaching on Eyrie Reef, March 2024. Photo: George Roff//CSIRO
Coral reefs around the world are in trouble due to our warming and acidifying oceans, but none are in quite so much trouble as Australia’s Great Barrier Reef. This year, it was hammered by a mass bleaching event even worse than previous years, and according to reports after the most recent one, 97 percent of the bleached coral at Lizard Island Reef has died.
“This is the first quantitative assessment of coral mortality from the last mass bleaching event,” wrote the authors of an article outlining the severity of the bleaching event. “We don’t know how much coral died beyond this reef. But we do know that, according to other aerial surveys, almost one-third of the Great Barrier Reef experienced ‘very high’ and ‘extreme’ levels of coral bleaching last summer.”
The Great Barrier Reef is tremendously important. At almost 133,000 square miles, it’s the world’s largest coral reef. It is home to nearly 2,000 different kinds of fish and a little over 400 different species of corals. It’s not just ecologically important, but also a driver of tourism that contributes billions of dollars to Australia’s tourism sector every year.
Bleaching is a relatively normal occurrence for brief time windows in small areas of the reef, but when it is widespread and lasts far longer than usual, it is decidedly bad. Bleaching refers to coral that spits out the algae that lives inside it due to stress like warmer than usual water or higher than normal acidity, both of which are occurring around the world.
This is the fifth mass bleaching event in the Great Barrier Reef in eight years. The algae that lives in the coral is what gives it those fantastic colors, so when they’re not around, the coral turns white, which is where the term “bleaching” comes from.
The extent of the die off was recorded by drones flying above Lizard Island. Then, researchers donned masks and snorkels for an up-close-and-personal look at the devastation.
Although bleached corals can bounce back, when it’s too severe the coral simply dies. Many environmental outfits around the world have been sounding the alarm for Australia to do something about the worsening issue before it’s too late.
“The current bleaching occurs as part of the fourth global mass bleaching, which is likely impacting at least 30 percent of the world heritage-listed coral reef properties, and the implications across the world heritage system will also need to be considered further,” Unesco experts wrote. [The reef] “remains under serious threat, and urgent and sustained action is of utmost priority in order to improve the resilience of the property in a rapidly changing climate.”
