The iconic Great Barrier Reef suffered a mass of coral bleaching over the summer and a survey of the extent of the damage has now been released.
Above-average water temperatures led to mass bleaching of corals on the Great Barrier Reef during the summer as the Australian icon was affected by climate change “escalating”, a new report has revealed.
The Great Barrier Reef Marine Park Authority (GBRM) in March confirmed a sixth mass bleaching event on the Great Barrier Reef, the fourth such event since 2016.
Unusually, it was the first mass bleaching event to occur in La Nina’s conditions, which are typically cooler.
Aerial surveys to examine the extent of bleaching found 91% of the 719 coral reefs assessed showed bleaching, according to the long-awaited Reef: Summer 2021-22 report released late Tuesday.
The report is a joint initiative of Australia’s leading science and management agencies for the Great Barrier Reef: the Great Barrier Reef Marine Park Authority, the Australian Institute of Marine Science and CSIRO.
The release of the report, which sheds light on how the reef fared last summer, was delayed and posted late Tuesday amid requests for release ahead of the May 21 federal election.
The snapshot said a “sea heatwave” was the only major pressure hitting the Great Barrier Reef from previous summers.
The waters warmed in early December 2021, surpassing all-time summer highs that typically occurred in the warmer summer months.
Ocean temperatures continued to accumulate heat throughout the summer until early April 2022, with three distinct heat waves increasing heat stress across the central and northern parts of the reef.
“This prolonged heat exposure has led to mass coral bleaching across the Great Barrier Reef; the fourth to occur in seven years, “the report said.
The bleached corals are still alive but stressed. Shallow or moderately bleached corals have a better chance of recovery if there are minimal impacts in subsequent years.
Severely bleached corals have higher mortality rates.
The report says climate change remains the biggest threat to the reef.
“It affects weather patterns and ocean temperatures, pH levels and currents, as well as intensifying the effects of other threats,” he said.
“Climate change is increasing and the coral reef is already suffering the consequences.
“Unfortunately, events causing reef disturbances are becoming more frequent, leaving less time for coral to recover.”
Aerial surveys by the GBRM and the Australian Institute of Marine Science in late March analyzed a sample of 719 reefs between the Torres Strait and the Capricorn Bunker Group in the Great Barrier Reef Marine Park.
A total of 654, or 91 percent, showed bleaching, ranging from mild to severe impact.
The report says underwater investigations would be key to understanding the fate of the bleached coral.
Lissa Schindler, Australian Marine Conservation Society Great Barrier Reef Campaign Manager, said the annual snapshot and bleaching map was “devastating” news for anyone who loved the reef.
Dr Schindler said it’s further proof that fossil fuel emissions need to be cut immediately and be a top priority for the next Australian government.
“This was a La Nina year, normally characterized by more cloudiness and rain. It should have been a welcome relief to our reef to help it recover, yet the snapshot shows that over 90% of the reefs examined showed bleaching, “she said.
“Although whitening is becoming more and more frequent, this is not normal and we must not accept that this is the case.
“We have to break the rules that are breaking down our coral reef.”
Dr Schindler said that although the ALP had a better emissions reduction target than the Coalition, the climate goals of both major political parties were not up to par when it came to the reef.
“That’s not enough for the 64,000 people who work in reef tourism and related industries, not for the millions of people around the world who have visited or want to visit the reef. This is an Australian icon that we must do everything in our power to protect, “she said.
“By taking the required action and embracing the tremendous opportunities of Australia’s renewable energy revolution, we can help protect tens of thousands of reef jobs and create thousands more in clean energy.”
Originally published as ‘Devastating’ report on ‘mass bleaching’ of the Great Barrier Reef published