Credit: Rebecca Falconer
Australia’s Great Barrier Reef has lost over half of its coral populations in the past three decades because of ocean warming, a study published in the journal Proceedings of the Royal Society Bpublished Wednesday finds.
Why it matters: The World Heritage-listed underwater ecosystem is a haven for biodiversity, with some 4,000 species of fish, 700 species of coral and “thousands of other species of plants and animals,” per the nonprofit Coral Reef Alliance. It spans some 1,400 miles — making it the largest coral reef ecosystem in the world.
What they did: Researchers from the ARC Centre of Excellence for Coral Reef Studies (CoralCoE), in Queensland, Australia, assessed coral communities and their colony size along the length of the Great Barrier Reef from 1995 to 2017.
What they found: Researchers discovered that climate change is driving an increase in the frequency of reef disturbances, such as marine heatwaves. Nearly every coral species has declined since the comprehensive research began.
“The decline occurred in both shallow and deeper water, and across virtually all species — but especially in branching and table-shaped corals. These were the worst affected by record breaking temperatures that triggered mass bleaching in 2016 and 2017.”
What they’re saying: Bob Richmond, director of the Kewalo Marine Laboratory at the University of Hawai’i at Manoa, who’s extensively researched reefs, told the Washington Postthe Australian research shows “demographic changes are occurring on a regional scale … on reef slopes that make it difficult for coral reefs to persist over time.”
The bottom line: “The loss of these corals means a loss of habitat, which in turn diminishes fish abundance and the productivity of coral reef fisheries,” the study notes.