- ‘Heartbreaking’ update reveals three-quarters of reef has been bleached
- Scientists fear time is running out to protect the Great Barrier Reef
Scientists fear time is running out to protect the Great Barrier Reef, which is suffering one of its most extensive coral bleaching events.
The full extent of the impact is still unknown, despite a heartbreaking update on Wednesday that revealed almost three-quarters of the reef has been affected.
The reef has suffered its worst summer on record after being hit by two tropical cyclones and severe flooding, as well as an outbreak of coral-eating crown-of-thorns starfish.
This has culminated in one of the most extensive and severe mass coral bleaching events recorded on the reef.
The 2023/24 Summer Update was published by the Great Barrier Reef Marine Park Authority, the Australian Institute of Marine Science and the CSIRO.
Scientists fear time is running out to protect the Great Barrier Reef, which is suffering one of its most extensive coral bleaching events.
The reef has suffered its worst summer on record after being hit by two tropical cyclones and severe flooding, as well as an outbreak of coral-eating crown-of-thorns starfish.
It provides information on the fifth mass bleaching of the reef in eight years due to heat stress caused by climate change.
Professor Terry Hughes of James Cook University said the narrowing interval between bleaching events was a major concern, casting doubt on any subsequent full recovery.
“We have already seen back-to-back bleaching events in two consecutive years in 2016-17 and the last three events, including this one, have only been two years apart,” he told AAP.
“That’s not enough for a full recovery or anything like that.”
Selina Ward, from the University of Queensland, said the clock was ticking to take action against climate change and protect the reef.
The full extent of the impact is still unknown despite a ‘heartbreaking’ update on Wednesday which revealed almost three-quarters of the reef has been affected.
This aerial photo taken on April 4, 2024 shows a coral atoll near Lizard Island on the Great Barrier Reef, located 167 miles north of the city of Cairns.
“We have less time… to make changes,” Dr Ward told AAP.
“We have to get really serious… we are certainly running out of time.”
According to the update, aerial surveys found that 73 percent of the 1,080 reefs monitored had suffered bleaching in the latest event.
Bleaching was “very high” or “extreme” on 39 percent of the reefs, with the highest levels in the southern region as well as parts of the rest of the central and northern areas.
“It’s a very serious and unfortunate bleaching phenomenon (after) some of the longest periods of warm water we’ve ever had on the Great Barrier Reef,” Dr Ward said.
“It’s really heartbreaking… it’s widespread and there are really high levels of extreme discoloration, more than usual.”
Extreme bleaching occurs when more than 90 percent of a reef’s coral cover is affected.
A very high level is given when more than 60 percent is bleached.
The severity of a bleaching event is rated on a category scale of one to five.
But the latest event won’t be assessed until the full extent of this summer’s record-breaking water temperatures is known, and scientists will prepare to monitor the impact over the next 12 months.
Extreme bleaching occurs when more than 90 percent of a reef’s coral cover is affected. A very high level occurs when more than 60 percent is bleached.
Bleaching is not always fatal, but corals are likely to die if temperatures remain higher than normal for too long.
It comes after a fourth global mass coral bleaching event was declared this week, affecting 53 nations.
Bleaching is not always fatal, but corals are likely to die if temperatures remain higher than normal for too long.
“Some (of the corals) will regain their color in the coming months, but not all will do so given the severity of this year’s bleaching,” Professor Hughes said.
WWF Australia has called on the Labor government to commit to a federal emissions reduction target of at least 90 per cent below 2005 levels by 2035 and to phase out fossil fuels.
“The Great Barrier Reef has become one of the most bleached reef systems in the world,” a spokesperson said.
‘The Caribbean has lost 80 percent of its coral cover. Is that the future we want for our national treasure?’