Stopping global warming is only way to save Great Barrier Reef, scientists warn
Improvements to water quality or fishing controls don’t prevent underwater heatwaves damaging coral, studies of mass bleaching events reveal
By Joshua Robertson
Mar 15 2017
The survival of the Great Barrier Reef hinges on urgent moves to cut global warming because nothing else will protect coral from the coming cycle of mass bleaching events, new research has found.
The study of three mass bleaching events on Australian reefs in 1998, 2002 and 2016 found coral was damaged by underwater heatwaves regardless of any local improvements to water quality or fishing controls.
The research, authored by 46 scientists and published in Nature, raises serious questions about Australia’s long-term conservation plan for its famous reef, which invests heavily in lifting water quality but is silent on climate-change action.
The researchers said the findings of their paper, Global Warming and Recurrent Mass Bleaching of Corals, applied to coral reefs worldwide.
Its publication comes the same day its lead author, Terry Hughes, is due to embark on an aerial survey to confirm the extent of another mass bleaching event on the Great Barrier Reef.
It is the first mass bleaching to occur for a second consecutive year on the reef, which suffered its worst ever damage in 2016 when 22% of coral was killed off in a single hit.
The study, which was unable to take in the effects of the latest event, warned a fourth mass bleaching event “within the next decade or two” gave the badly damaged northern section of the reef a “slim” chance of ever recovering to its former state.
Hughes said the latest event, which was notable for having nothing to do with the warming effect of El Niño weather patterns, highlighted how research on mass bleaching, even when fast-tracked, was unable to keep pace with the reef’s current state.
“It broke my heart to see so many corals dying on northern reefs on the Great Barrier Reef in 2016,” Hughes said.
“With rising temperatures due to global warming, it’s only a matter of time before we see more of these events. A fourth event after only one year would be a major blow to the reef.”
Hughes said he hoped coming weeks would “cool off quickly and this year’s bleaching won’t be anything like last year”.
“The severity of the 2016 bleaching was off the chart.”
Hughes, the convener of the National Coral Bleaching Taskforce, said the study clearly showed the need for climate change action in Australia’s reef conservation plan.
He said it also showed the folly of Australian and Queensland government support for one of the world’s largest coalmines, Adani’s proposed Carmichael mine, which will export coal in ships through reef waters.
This was not only because of the carbon emissions from the coal, but also from dredging and marine traffic through the reef.