Scientists are alarmed after the Great Barrier Reef in Australia is hit by the worst coral bleaching in its history.
An aerial survey of more than 500 coral reefs making up the system has revealed that almost all have suffered severe bleaching, with the researchers labeling it the worst mass bleaching event in the World Heritage Site’s history.
Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures. This causes stress on the algae living inside the coral, in turn leading the coral to expel them from their tissue. And because these colorful algae are critical to coral health, their departure leaves the coral withering, white and in danger of dying.
“This has been the saddest research trip of my life,” says Professor Terry Hughes, convenor of the National Coral Bleaching Taskforce. “Almost without exception, every reef we flew across showed consistently high levels of bleaching, from the reef slope right up onto the top of the reef. We flew for 4,000 km (2,485 mi) in the most pristine parts of the Great Barrier Reef and saw only four reefs that had no bleaching. The severity is much greater than in earlier bleaching events in 2002 or 1998.”
