After two years of back-to-back bleaching events, Australia’s 2,300 kilometers (1,430 miles) long Great barrier Reef has been damaged almost beyond belief. The latest surveys by scientists from James Cook University show that 1,500 km (932 miles) of the reef have now been bleached.
CNN is reporting the bleaching has become so extensive, that it appears the Great barrier Reef is being cooked to death by the elevated ocean temperatures.
Prof. Terry Hughes, Director of the ARC Centre of Excellence for Coral Reef Studies, who undertook the aerial surveys in both 2016 and 2017 says, “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.”
There is great fear that if normal conditions don’t return, the reef won’t be able to recover. Bleaching is a stress response that occurs when ocean temperatures rise, causing the expulsion of algae that grows inside coral. This results in coral bleaching, the dead white look we see in so many images today.
Marine biologist David Suggett, with the University of Technology-Sydney, explains that for the corals to properly recover they need to be connected to areas of the reef not affected by the bleaching so that the algae can reestablish itself.
Added to the apparent loss of connectivity are the destructive crown-of-thorns starfish and poor water quality. Plus, the category four tropical cyclone Debbie came too late and too far south for its cooling effect to alleviate bleaching. Hughes said the storm’s slow movement across the reef likely destroyed coral in a path up to 100 kilometers wide.
According to data from the survey, the 2016 bleaching event was concentrated in the reef’s northern third, while the 2017 event spread further south, with the greatest damage occurring in the middle section of the Great Barrier Reef. This year’s mass bleaching is second in severity only to 2016, and El Nino wasn’t responsible.
It should be noted that the aerial survey techniques used in this study were employed consistently in all four bleaching events on the Great Barrier Reef: 1998, 2002, 2016 and 2017. They were backed up by extensive in-water research during the 2016 event and published in the peer-reviewed journal, Nature.
Water quality expert, Jon Brodie, told the Guardian the reef is now in a “terminal stage.” Corals can recover from bleaching events, he points out, but having back-to-back years of very high temperatures that resulted in bleaching, doesn’t give the reef any time to recover, and instead, just adds to the destruction.
He added that the Australian government’s efforts to improve water quality by stopping run-off from nearby catchments have failed. “We’ve given up. It’s been my life managing water quality, we’ve failed,” Brodie said. “Even though we’ve spent a lot of money, we’ve had no success.”
Brodie is very upset, especially because he has spent much of his adult life working to improve the water quality on the reef.
“Last year was bad enough, this year is a disaster year,” Brodie said. “The federal government is doing nothing really, and the current programs, the water quality management is having very limited success. It’s unsuccessful.”
