Mass coral bleaching now affecting half of Australia's Great Barrier Reef

Climate change and strong El Nino cause hundreds of kilometres of reef to bleach, as higher temperatures stress the coral

The mass coral bleaching event smashing the Great Barrier Reef has severely affected more than half its length and caused patches of bleaching in most areas, according to scientists conducting an extensive aerial survey of the damage.

"The good news with my last flight is that I found 50 reefs that weren't bleached, so that may be the southern boundary," said Terry Hughes from James Cook University. Hughes is the head of the national coral bleaching task force, which has been conducting flights over the length of the reef, mapping bleached areas and recording the severity of the damage.