91% of Great Barrier Reef ‘bleached’
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 on Tuesday, conducted extensive surveys of the World Heritage-listed reef between September last year and March.
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.
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.
“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.”