Large sections of Australia's Great Barrier Reef are dead or dying, while other parts are severely damaged, and climate change is to blame, according to a new study published in Nature. The reef is now in a "terminal stage," an expert tells the Guardian, after unprecedented back-to-back bleaching events in 2016 and 2017.
Using aerial and underwater surveys as well as satellites to measure sea temperatures, researchers found that Australia's heatwave in the summer of 2016 triggered a wave of coral bleaching that was completely unexpected. Just north of the Port Douglas area of the reef, for example, 67 percent of the corals died; in some patches, the coral death rate hit 83 percent. The 2017 bleaching was second in severity only to the 2016 event, and hit southern stretches of reef that were largely spared in 2016.
"We didn't expect to see this level of destruction to the Great Barrier Reef for another 30 years," Terry P. Hughes, the lead author of a paper, told the New York Times. Hughes is also the director of a center for coral reef studies at James Cook University. "In the north, I saw hundreds of reefs — literally two-thirds of the reefs were dying and are now dead."
Dead coral results in fewer habitats for many forms of aquatic life, aquatic life that we rely on for food and for tourism.
Also troubling is that localized efforts to stop or slow bleaching are not working. Australia's Reef 2050 plan, which includes measures to restrict port development and reduce agricultural runoff, hasn't been enough to offset ever-hotter temperatures.
"The reefs in muddy water were just as fried as those in pristine water," Hughes said. "That's not good news in terms of what you can do locally to prevent bleaching — the answer to that is not very much at all. You have to address climate change directly."
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