Great Barrier Reef on brink of third major coral bleaching in five years, scientists warn

If ocean temperatures don't drop in the next two weeks, heat stress could tip reef over into another widespread event

The Great Barrier Reef could be heading for a third major coral bleaching outbreak in the space of five years if high ocean temperatures in the region do not drop in the next two weeks, scientists and conservationists have warned.

Heat stress is already building across the world's biggest reef system, with reports of patchy bleaching already occurring. But a major widespread event is not currently taking place.