Australia’s Great Barrier Reef has lost more than half its coral cover in the past 27 years due to storms, predatory starfish and bleaching linked to climate change, a study released yesterday found.
The research by scientists from the Australian Institute of Marine Sciences (AIMS) and the University of Wollongong warned that coral cover on the heritage-listed reef — the world’s largest — could halve again by 2022 if trends continued.
Intense tropical cyclones — 34 in total since 1985 — were responsible for much of the damage, accounting for 48 percent, with outbreaks of the coral-feeding crown-of-thorns starfish linked to 42 percent.
Photo: AFP / Ray Berkelmans / Australian Institute of Marine Science
Two severe coral bleaching events in 1998 and 2002 due to ocean warming also had “major detrimental impacts” on the central and northern parts of the reef, the study found, putting the impact at 10 percent.
Two-thirds of the loss had occurred since 1998, with the rate of decline increasing substantially and only three of the 214 individual reefs surveyed across the sprawling 345,000km2 site escaping any impact.
“This loss of over half of initial cover is of great concern, signifying habitat loss for the tens of thousands of species associated with tropical coral reefs,” the study said.
Author Hugh Sweatman said the findings, which were drawn from the world’s largest ever reef monitoring project involving 2,258 surveys over 27 years, showed that coral could recover from such trauma.
“But recovery takes 10-20 years. At present, the intervals between the disturbances are generally too short for full recovery and that’s causing the long-term losses,” Sweatman said.
The study said cyclone intensities were increasing as the world’s oceans warmed and bleaching deaths would “almost certainly increase” as a result of climate changes.
“The recent frequency and intensity of mass coral bleaching are of major concern, and are directly attributable to rising atmospheric greenhouse gases,” it said. “Mitigation of global warming and ocean acidification is essential for the future of the great barrier reef.”
AIMS chief John Gunn said it was difficult to stop the storms and bleaching, but researchers could focus their short-term efforts on the large, poisonous and spiny starfish, which feasts on coral polyps and can devastate reef cover.
The study said improving water quality was key to controlling starfish outbreaks, with increased agricultural run-off such as fertilizer along the reef coast causing algal blooms that starfish larvae feed on.
“We can’t stop the storms but perhaps we can stop the starfish,” Gunn said. “If we can, then the reef will have more opportunity to adapt to the challenges of rising sea temperatures and ocean acidification.”
He said researchers would try to “better predict and reduce the periodic population explosions” of the starfish and explore whether direct intervention methods could be useful.
According to the study, published in Proceedings of the National Academy of Sciences, coral cover would be able to rejuvenate by 0.89 percent every year without the starfish.
“So even with losses due to cyclones and bleaching there should be slow recovery,” Gunn said.
UNESCO warned it was considering listing the reef as a heritage site in danger earlier this year due to the unprecedented gas and coal mining boom in northern Australia and increasing coastal development.
As the sun sets on another scorching Yangon day, the hot and bothered descend on the Myanmar city’s parks, the coolest place to spend an evening during yet another power blackout. A wave of exceptionally hot weather has blasted Southeast Asia this week, sending the mercury to 45°C and prompting thousands of schools to suspend in-person classes. Even before the chaos and conflict unleashed by the military’s 2021 coup, Myanmar’s creaky and outdated electricity grid struggled to keep fans whirling and air conditioners humming during the hot season. Now, infrastructure attacks and dwindling offshore gas reserves mean those who cannot afford expensive diesel
Does Argentine President Javier Milei communicate with a ghost dog whose death he refuses to accept? Forced to respond to questions about his mental health, the president’s office has lashed out at “disrespectful” speculation. Twice this week, presidential spokesman Manuel Adorni was asked about Milei’s English Mastiff, Conan, said to have died seven years ago. Milei, 53, had Conan cloned, and today is believed to own four copies he refers to as “four-legged children.” Or is it five? In an interview with CNN this month, Milei referred to his five dogs, whose faces and names he had engraved on the presidential baton. Conan,
‘IN A DIFFERENT PLACE’: The envoy first visited Shanghai, where he attended a Chinese basketball playoff match, and is to meet top officials in Beijing tomorrow US Secretary of State Antony Blinken yesterday arrived in China on his second visit in a year as the US ramps up pressure on its rival over its support for Russia while also seeking to manage tensions with Beijing. The US diplomat tomorrow is to meet China’s top brass in Beijing, where he is also expected to plead for restraint as Taiwan inaugurates president-elect William Lai (賴清德), and to raise US concerns on Chinese trade practices. However, Blinken is also seeking to stabilize ties, with tensions between the world’s two largest economies easing since his previous visit in June last year. At the
Beijing is continuing to commit genocide and crimes against humanity against Uyghurs and other Muslim minorities in its western Xinjiang province, U.S. Secretary of State Antony Blinken said in a report published on Monday, ahead of his planned visit to China this week. The State Department’s annual human rights report, which documents abuses recorded all over the world during the previous calendar year, repeated language from previous years on the treatment of Muslims in Xinjiang, but the publication raises the issue ahead of delicate talks, including on the war in Ukraine and global trade, between the top U.S. diplomat and Chinese