The survival of the Great Barrier Reef rests on cutting global warming, with efforts to improve water quality and fishing doing little to prevent major bleaching, according to a new study.

The study, released in the scientific journal Nature, shows protecting it from fishing and poor water quality is doing little to prevent bleaching.

"Global warming is the number one threat to the reef. The bleaching in 2016 strongly reinforces the urgent need to limit climate change," said co-author David Wachenfeld from the Great Barrier Reef Marine Park Authority.

The reef experienced the worst coral bleaching on record last summer with protective efforts making no difference to the amount of bleaching during the extreme weather.


"With rising temperatures due to global warming, it's only a matter of time before we see more of these events," Wachenfeld said.

Coral researchers will take to the sea and the air to examine the reef to determine whether the recent heatwave caused further damage.

"We're hoping that the next two to three weeks will cool off quickly and this year's bleaching won't be anything like last year," Australian Research Council Centre of Excellence taskforce convener Terry Hughes said.

"It was the third major bleaching to affect the Great Barrier Reef, following earlier heatwaves in 1998 and 2002. Now we're gearing up to study a potential number four."

Hughes said scientists had found no evidence that past exposure to bleaching toughened the corals.

The study found that while protective measures did not prevent bleaching last year, improving water quality and protecting the reefs from fishing was likely to help bleached reefs recover in the longer term.