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The bad news for Australia’s Great Barrier Reef just keeps on getting worse.

Last month, scientists from James Cook University in Townsville, Australia, reported that the northern third of the reef was severely bleached in 2016. Well over half the corals there were lost in that event.

Today, the same team announced that the central portion of the reef, a popular tourist area, is now suffering a similar fate. Corals bleach – and can die – when stresses such as abnormal heat make them expel their symbiotic algae.

In 2016, the bleaching was caused by El Niño, a periodic global climate event that heats up a vast band of the ocean’s surface in the equatorial Pacific.

But this year’s bleaching is occurring during a so-called “normal” year without such an event.

“The water is just too damn hot,” says Terry Hughes, the leader of the survey, who fears that climate change is creating a new norm that corals are unable to endure.

Hughes flew over the worst-affected area in a small aircraft to investigate the gradual whitening of the reef, which started to be noticeable in early February. Nearly 200 divers have also been documenting the destruction under the waves.

Recovery fears

It will take up to nine months to find out how many of the bleached corals end up dying, but Hughes fears that the central reef may have been nearly as badly damaged this year as the northern part was last year, when 67 per cent of the corals were lost there.

“Our combined 2016 and 2017 surveys show that two-thirds of the Great Barrier Reef has now been badly degraded,” says Hughes.

It is a loss that under normal circumstances would take a decade to recover from. “But now that bleaching is happening every year or every other year in some areas, recovery will be difficult if not impossible,” he says.

“This is really scary, because the Great Barrier Reef is losing its insurance policy,” says marine biologist Randi Rotjan at Boston University in Massachusetts. “The scale of the devastation means that it is losing its potential to reseed the parts of the reef that were previously damaged.”

Read more: Face-to-face with Great Barrier Reef’s worst coral bleaching