GREG TORDAThe bleaching of Australia’s Great Barrier Reef continues to be the worst such event in recent memory, according to a report from researchers at James Cook University, released yesterday (April 10). Last June, the team found that the subsiding El Niño had affected more than 90 percent of the reef, making it “the sickest we’ve ever seen,” Bill Leggat, associate professor with the ARC Centre of Excellence for Coral Reef Studies, told The Scientist at the time. Now, aerial surveys covering the entire reef system have revealed that, while bleaching had been most severe in the northern third, the middle third now has the most intense coral bleaching.
“The combined impact of this back-to-back bleaching stretches for 1,500 km (900 miles), leaving only the southern third unscathed,” Terry Hughes, director of James Cook’s ARC Centre of Excellence for Coral Reef Studies, said in a press release. “The bleaching is caused by record-breaking temperatures driven by global warming. This year, 2017, we are seeing mass bleaching, even without the assistance of El Niño conditions.”
This year’s aerial surveys imaged more than 8,000 km (5,000 miles) of the Great Barrier Reef, allowing the researchers to score nearly 800 individual coral reefs. The same approach has been used to examine the effects of three previous bleaching events in 1998, 2002, and 2016. Last year, these data were supported by underwater surveys, which were published last last ...
