Reef suffers another hit
ABOVE average water temperatures led to a mass coral bleaching of the Great Barrier Reef over summer, as the Aussie icon was impacted by “escalating” climate change, 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 under La Nina conditions, which are typically cooler.
Aerial surveys to examine the extent of bleaching found 91 per cent of 719 reefs assessed showed some bleaching, according to the longawaited Reef snapshot: Summer 2021-22 report released late on Tuesday.
The report is a joint initiative of the Australian government’s lead management and science 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 has fared over the past
summer, was delayed and published late on Tuesday amid calls for its release before the federal election.
The snapshot said a “marine heatwave” was the one
major pressure affecting the Great Barrier Reef compared with previous summers.
Waters warmed early in December 2021, exceeding historical summer maximums
that typically occurred in the hottest summer months.
Ocean temperatures continued to accumulate heat throughout the summer until early April 2022, with three
distinct heatwaves increasing thermal stress throughout the reef’s central and northern parts.
“This prolonged heat exposure led to a mass bleaching of coral across the Great Barrier Reef; the fourth to occur in seven years,” the report said.
The report said climate change remained the reef’s greatest threat.
“It influences weather patterns and the ocean’s temperature, ph level and currents as well as intensifying the effects of other threats,” it said.
“Climate change is escalating and the reef is already experiencing the consequences of this.
“Unfortunately, the events that cause disturbances on the reef are becoming more frequent, leaving less time for coral recovery.”
Australian Marine Conservation Society Great Barrier Reef campaign manager Lissa Schindler said the annual snapshot and bleaching map was “devastating” news for anyone who loved the reef.
Dr Schindler said it was yet more evidence that fossil fuel emissions must be slashed immediately and be a top priority for the next government.
Dr Schindler said although the ALP had a better emissions reduction target than the Coalition, both major political parties’ climate goals fell short when it came to the reef.