Scientists from the ARC Center of Excellence for Coral Reef Studies in Australia have recorded more bad news for Australia’s Great Barrier Reef. It is undergoing a further bleaching episode, primarily in the previously unaffected middle third of the reef. The northern end was bleached in 2016, so this leaves only the southern third unaffected.

Prof. Peter Hughes of the center gives the reason for the bleaching: “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.”

The researchers carried out aerial surveys over 8,000 km (5,000 miles) and of 800 individual reefs.