91% of the Great Barrier Reef bleached by heatwave: Report
SYDNEY: A prolonged summer heatwave in Australia left 91% of the Great Barrier Reef’s coral damaged by bleaching, according to a new government monitoring report.
It was the first time on record the reef had suffered bleaching during a La Nina weather cycle, when cooler temperatures would normally be expected.
The Reef Snapshot report offered new details of the damage caused by the fourth “mass bleaching” the world’s largest coral reef system has experienced since 2016, which was first revealed in March.
“Climate change is escalating, and the Reef is already experiencing the consequences of this,” the report warned.
The Great Barrier Reef Marine Park Authority, which published the report late Tuesday, conducted extensive surveys of the World Heritage-listed reef between September 2021 and March 2022.
It found that after waters began to warm last December, all three major regions of the reef experienced bleaching - a phenomenon that occurs when coral is stressed and expels brightly coloured algae living in it.
‘Higher mortality’
Although bleached corals are still alive, and moderately affected sections of the reef may recover, “severely bleached corals have higher mortality rates”, the report said.
Of the 719 reefs surveyed, the report said 654 - or 91%- showed some level of coral bleaching.
The report was published 10 days before Australia’s May 21 federal election, in which climate change policy has emerged as a key issue for voters.
Australia’s 2019-2020 Black Summer bushfires and deadly east coast floods that swept away cars and engulfed homes this year have highlighted the country’s growing climate risks.
Prime Minister Scott Morrison has, however, resisted calls to make the country’s 2030 emissions reduction target more ambitious, while vowing to mine and export coal for as long as there are buyers. The Labour opposition has promised to boost renewables and commit to a 43% cut in greenhouse gases by 2030 but made no mention of phasing out coal burning.
‘Not normal’
“Although bleaching is becoming more and more frequent, this is not normal, and we should not accept that this is the way things are,” Australian Marine Conservation Society campaigner Lissa Schindler said.
“Both major political parties need to face up to the fact that their climate goals are not enough for the Reef.”
Next month, the United Nations’ World Heritage Committee will decide whether to list the reef as “in danger”.