‘Devastating’: 91% of surveyed Great Barrier Reef reefs were affected by coral bleaching in 2022 | Great Barrier Reef – Advice Eating

Coral bleaching affected 91% of reefs surveyed along the Great Barrier Reef this year, according to a report by government scientists confirming the natural landmark has suffered its sixth mass bleaching event on record.

The Reef Snapshot: Summer 2021-22, quietly released Tuesday night after a weeks-long delay by the Great Barrier Reef Marine Park Authority, said above-average late summer water temperatures across the 2,300km-long reef system, but particularly in , had led to coral bleaching the central region between Cape Tribulation and the Whitsundays.

“The surveys confirm a mass bleaching event, with coral bleaching observed on multiple reefs in all regions,” said a statement accompanying the report. “This is the fourth mass bleaching event since 2016 and the sixth since 1998 on the Great Barrier Reef.”

It was the first mass bleaching event recorded during a cooler La Niña year.

Scientists from the Marine Parks Authority and the Australian Institute of Marine Science surveyed 719 shallow water reefs between Torres Strait and the Capricorn Bunker Group at the southern end of the reef system, mostly using helicopters. They found that 654 reefs were slightly bleached.

Map of 2022 aerial observations of reef community coral bleaching across the Great Barrier Reef after the last heat wave of March 12-23, 2022
Coral bleaching affected more than 90% of surveyed reefs along the Great Barrier Reef in 2022. Photo: Great Barrier Reef Marine Park Authority

A map released with the report shows the most severe and extreme bleaching has occurred in the region, which includes the areas most frequented by tourists. According to the report, coastal and offshore reefs were badly affected.

Marine Parks Authority scientists could not be reached Tuesday night to comment on the report. The agency’s chief scientist, Dr. David Wachenfeld told the Guardian in March that bleaching is not expected in a La Niña.

“Even so, the climate is changing and the planet and reef are about 1.5 degrees warmer than they were 150 years ago,” he said. “That’s why the weather changes. Unexpected events are now to be expected. Nothing surprises me anymore.”

Lissa Schindler, campaign manager at the Australian Marine Conservation Society, said the report was “devastating news for all those who love the reef” and “yet more evidence” that cutting fossil fuel emissions is a top priority for Australia’s next government should have priority.

“This was a La Nina year, typically characterized by more cloud cover and rain,” she said. “It should have been a welcome respite for our reef to help it recover, and yet the snapshot shows that over 90% of the reefs surveyed had some bleaching.

“Although bleaching is becoming more and more common, it is not normal and we should not accept it. We need to break the norms that are breaking our reef.”

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Schindler said while Labor is committed to making bigger emissions cuts than the coalition by 2030, neither party has targets in line with what would be needed globally to save the reef.

The Intergovernmental Panel on Climate Change found that limiting global warming to 1.5°C instead of 2°C would likely mean the difference between the survival of some tropical reef corals and their complete decline. A report by Climate Analytics found that the coalition’s 2030 emissions reduction target is in line with more than 3C heating bills and Labour’s target of around 2C.

The Research Director of the Climate Council, Dr. Simon Bradshaw, said: “This is a problem that cannot be solved with big shiny funding announcements. The science is very clear: to save the world’s reefs from total destruction, we must drastically reduce emissions in the 2020s.”

Scientists began sounding the alarm about this year’s bleaching event in December, when sea temperatures over the reef hit a record high for the month.

Bleaching occurs when the coral is stressed by above average water temperatures. The coral animal expels the photosynthetic algae that live in it and provides the coral with food and colour.

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Corals can survive bleaching events. Scientists plan to do checks in the water by the end of the year to see how many corals have survived and regained their algae and color.

Studies have shown that heat stress can have several “sub-lethal” effects on corals, including making them susceptible to disease, slowing their growth and limiting their ability to spawn.

The findings of the survey are expected to inform a report by a United Nations mission that visited the reef in March to review its condition and management. Scientists from Unesco and the International Union for Conservation of Nature were briefed on the investigations during the 10-day monitoring trip. Your report is due before the next World Heritage meeting, currently scheduled for June.

Last year, Unesco scientific advisors recommended putting the reef on a list of World Heritage sites “at risk” due to the impact of the climate crisis and slow progress in improving water quality. Continued lobbying by the Morrison government led the 21-country committee to oppose this advice.

The release of the report and maps follows scientists and conservationists calling on the ocean agency to release them. SBS reported that Paul Hardisty, chief executive of the Australian Marine Institute of Science, said at a meeting of his staff that the Prime Minister’s and Cabinet Office’s recommendation that the poll results be made public during the general election campaign was against caretaker conventions.

Conservationists have also urged the government to release the State of the Environment Report, a five-yearly national assessment it has been working with Environment Secretary Sussan Ley since December.

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