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We've known for a while that coral reefs are dying off the coast of Australia because of climate change. Now scientists have mapped the extent of the destruction. NPR's Merrit Kennedy reports.
MERRIT KENNEDY, BYLINE: The Great Barrier Reef is the world's largest. It's brightly colored, swarming with fish and wildlife. But recently marine heat waves have been killing off large sections of the reef, and that has scientists asking a tough question.
MARK EAKIN: Who lives, and who dies?
KENNEDY: Who lives, and who dies? That's Mark Eakin with the National Oceanic and Atmospheric Administration. He and other scientists have been mapping the impacts of heat on more than 1,400 miles of reef. The researchers studied a major heat wave in 2016. Warmer waters caused by climate change swept through the northern parts of the reef. The heat stress killed much of the coral.
EAKIN: The majority of the reefs in the northern Great Barrier Reef were essentially destroyed.
KENNEDY: When those reefs died, it impacted other life, too, creatures like fish and shrimp, even worms. The ecosystems have collapsed on 1 in every 3 reefs, according to the new study in Nature. Some corals have survived the warmer temperatures. They are likely to dominate the reefs in the future. And Eakin says that means those reefs will have fewer species on them.
EAKIN: The high biodiversity of coral reefs is one of the things that makes them so important. And we're losing a lot of that diversity.
KENNEDY: The heat waves continue. Another bleaching event hit last year, striking the southern part of the reef. Unless climate change can be slowed, Eakin says, this transformation will go on for decades. Merrit Kennedy, NPR News.
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