Almost 93% of reefs on the Great Barrier Reef have been hit by coral bleaching, according to a comprehensive survey revealing the full extent of the devastation caused by abnormally warm ocean temperatures sweeping the globe.
There have only been three mass bleaching events recorded on the reef , and all of them have happened since 1998. Scientists say this episode is the worst they’ve ever seen.
The world is in the midst of a global bleaching event, which is a result of a pulse of warm water flowing around the Pacific Ocean caused by El Niño, and the background global warming caused by man-made greenhouse gas emissions.
Corals bleach when they experience temperatures above their normal summer maximum for a month or two. The situation is made worse if there are few clouds, and a high level of UV radiation blasts the coral.