But an Australian government study released last week found that over all, last year brought “the highest sea surface temperatures across the Great Barrier Reef on record.”
Only 9 percent of the reef has avoided bleaching since 1998, Professor Hughes said, and now, the less remote, more heavily visited stretch from Cairns south is in trouble again. Water temperatures there remain so high that another round of mass bleaching is underway, the Great Barrier Reef Marine Park Authority confirmed last week.
Professor Hughes said he hoped the die-off this time would not be as serious as last year’s, but “back-to-back bleaching is unheard-of in Australia.” The central and southern part of the reef had already been badly damaged by human activities like dredging and pollution.
The Australian government has tried to combat these local threats with its Reef 2050 plan, restricting port development, dredging and agricultural runoff, among other risks. But Professor Hughes’s research found that, given the high temperatures, these national efforts to improve water quality were not enough.
“The reefs in muddy water were just as fried as those in pristine water,” Professor Hughes said. “That’s not good news in terms of what you can do locally to prevent bleaching — the answer to that is not very much at all. You have to address climate change directly.”
With the election of Donald J. Trump as the American president, a recent global deal to tackle the problem, known as the Paris Agreement, seems to be in peril. Australia’s conservative government also continues to support fossil fuel development, including what…