Scientists say an underwater heat wave in Australia’s Great Barrier Reef has led to devastating coral bleaching – the worst in history – which has damaged or killed 95 per cent of the northern reefs.
An aerial survey of 520 sites across the 1,500-mile stretch of delicate coral reefs in north-east Australia found that the most pristine sections had been “fried” and were facing some of the worst bleaching in recorded history.
Long stretches of the famously colourful reef, which is world heritage-listed and one of the country’s top tourist destinations, have turned “snow-white” following bleaching which began six months ago, according to the researchers.
“This will change the Great Barrier Reef forever,” Professor Terry Hughes, from James Cook University, told ABC News.
“We’re seeing huge levels of bleaching in the northern thousand-kilometre stretch of the Great Barrier Reef. It’s too early to tell precisely how many of the bleached coral will die, but judging from the extreme level even the most robust corals are snow white, I’d expect to see about half of those corals die in the coming month or so.”
Scientists believe the bleaching was triggered by a temperature spike due to the El Niño weather pattern, which added to already warmer waters caused by climate change. Warmer temperatures can kill the tiny marine algae which are required to maintain the health of coral and give it colour.
It is the third and worst bleaching phenomenon since 1998 but there is no evidence of any other events in history.
“The north has fried,” said Professor Hughes. “This is an ongoing, slow-motion train wreck.”
The bleaching has affected virtually all species of the reef’s coral.
Cloudy weather is believed to have kept temperatures down and prevented heavy damage in the southern parts of the reef.
The damage has raised fresh questions about whether UNESCO may list the marine park as “in danger”. The organisation last year decided not to downgrade the park’s listing but expressed concern about the damage caused by mining and coastal pollution.
Conservationists and scientists urged Malcolm Turnbull, the prime minister, to visit the reef and limit mining in the region and to take action to reduce carbon emissions.
“The reef is one of the wonders of the world,” Imogen Zethoven, from the Australian Marine Conservation Society, told Fairfax Media.
“It is being ruined by global warming in front of our eyes.”
Scientist in Australia have warned for years that climate change has led to warmer waters which threaten the long-term future of the reef.
“What we’re seeing now is unequivocally to do with climate change,” Professor Justin Marshall, from the University of Queensland, told ABC News.
“The world has agreed, this is climate change, we’re seeing climate change play out across our reefs.”
Greg Hunt, the federal environment minister, flew over the area earlier this month and pledged to add further resources to monitor the health of the reefs.
“There’s good and bad news — the bottom three quarters of the reef is in strong condition,” he said.
“But as we head north of Lizard Island it becomes increasingly prone to bleaching.”
Source: Telegraph news