SYDNEY (Reuters) - Warm seas around Australia’s Great Barrier Reef have killed two-thirds of a 700-km (435 miles) stretch of coral in the past nine months, the worst die-off ever recorded on the World Heritage site, scientists who surveyed the reef said on Tuesday.

Their finding of the die-off in the reef’s north is a major blow for tourism at reef which, according to a 2013 Deloitte Access Economics report, attracts about A$5.2 billion ($3.9 billion) in spending each year.

“The coral is essentially cooked,” professor Andrew Baird, a researcher at James Cook University who was part of the reef surveys, told Reuters by telephone from Townsville in Australia’s tropical north.

He said the die-off was “almost certainly” the largest ever recorded anywhere because of the size of the Barrier Reef, which at 348,000 sq km (134,400 sq miles) is the biggest coral reef in the world.

Bleaching occurs when the water is too warm, forcing coral to expel living algae and causing it to calcify and turn white. Mildly bleached coral can recover if the temperature drops and the survey found this occurred in southern parts of the reef, where coral mortality was much lower.

While bleaching occurs naturally, scientists are concerned that rising sea temperatures caused by global warming magnifies the damage, leaving sensitive underwater ecosystems unable to recover.

UNESCO’s World Heritage Committee stopped short of placing the Great Barrier Reef on an “in danger” list last May but asked the Australian government for an update on its progress in safeguarding the reef.

Australia will lodge that update on Friday, said a spokesman for Environment Minister Josh Frydenberg. In June, during an election campaign, Prime Minister Malcolm Turnbull promised A$1 billion in spending to protect the reef.

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Climate scientists argue that increased carbon dioxide in the atmosphere traps heat radiating from earth, creating global warming. Australia is one of the largest carbon emitters per capita because of its reliance on coal-fired power plants for electricity.

“Climate change is killing the Great Barrier Reef,” said environmentalist Charlie Wood, director of 350.org, an anti-fossil fuels movement.

“The continued mining and burning of coal, oil and gas is irreparably damaging the climate. If we want our kids to enjoy the Great Barrier Reef for generations to come, we must act now to keep fossil fuels in the ground,” Wood said in an emailed statement. </s> CANBERRA, Australia — Australian scientists say warming oceans this year have caused the biggest die-off of corals ever recorded on Australia's Great Barrier Reef.

The Australian Research Council Centre of Excellence for Coral Reef Studies said Tuesday that the worst-affected area was a (400-mile) swath in the north of the World Heritage-listed 2, (1,400-mile) chain of reefs off Australia's northeast coast.

It found that the northern swath had lost an average of 67 of its shallow-water corals in the past nine months.

The based its findings on dive surveys in October and November.

The governments of Australia and the state of Queensland will update the UNESCO World Heritage Center this week on progress being made to protect and improve the reef, including their response to coral bleaching. </s> Sign up for one of our email newsletters.

Scientists just back from a 5,000 mile aircraft survey of Australia's Great Barrier Reef pronounced a dire verdict Sunday: Warm waters have severely bleached large swaths of its corals for the second year in a row in a deadly one-two punch.

In 2016, two thirds of corals in the northern sector of the reef died after severe bleaching from unusually warm waters. Now this year, researchers with the ARC Centre of Excellence for Coral Reef Studies at James Cook University in Queensland, who reported the previous findings, say that the reef's central sector has been hit by another year of damaging warmth.

“We've had a back-to-back bleaching for the first time,” said Terry Hughes, who directs the center. “So we redid our aerial surveys again, which was a bit tough. I was hoping to never have to do it again.”

After that first survey, Hughes tweeted: “I showed the results of aerial surveys of #bleaching on the #GreatBarrierReef to my students, And then we wept.”

Coral bleaching occurs when unusually warm waters provide a stress to corals that in turn trigger a mass exodus of photosynthetic algae, called zooxanthellae, from their cells. The corals lose color and turn white, an outward indicator that their metabolism has been upended. The stronger the bleaching and the longer it goes on, the more likely corals are to die.

The Great Barrier Reef, the largest structure of its kind, is about 1,400 miles long. Nine hundred miles of that length have now experienced severe bleaching at some point during the past two years.

This year has seen the major bleaching shift southward, toward reefs just offshore of major population centers such as Cairns and Townsville.

The current survey encompassed 800 individual coral reefs — including many surveyed last year.

“Last year we lost 67 percent on average of the corals in the northern 430 miles of the barrier reef, between March and October,” Hughes said. “We're likely to see something similar happen now in the middle third this year.”

“That's obviously an enormous loss over two-thirds of the Great Barrier Reef,” he added. “I wouldn't say the barrier reef is dying. But clearly, we're measuring serious losses here. And the reason it's happening is global warming.”

Temperatures in the waters surrounding the reef were so abnormally high last year that scientists concluded there was little doubt they could be attributed to a changing climate.

There have been four historic bleachings of the Great Barrier Reef in the past two decades as the planet has warmed by about 1.8 degrees, Hughes notes.

The prior large scale bleachings occurred in 1998, a dramatic El Niño year, and 2002. 2016 was another major El Niño year, but 2017 is not. Thus, the reef is now bleaching in both non-El Niño years and in consecutive years.

If major bleachings are becoming more common, that raises questions about the reef's ability to recover from such assaults at a time when global ocean temperatures are expected to continue to rise further.

Typically, corals require 10 years or more to recover from bleaching. Some species require considerably longer than that.

Scientists fear the planet will easily coast past 1.5 degrees Celsius in coming decades — and 2 degrees of warming will also be very difficult to prevent with the current warming trajectory.

A 2016 scientific study found that most of the world's corals will be threatened with “severe degradation” under either of these two warming scenarios. But limiting the Earth's warming to 1.5 degrees by the end of the century might allow at least some corals to adapt to the new climate. </s> In just nine months, bleaching caused by warmer water has killed around 67% of the coral in a previously pristine part of the reef, one of the natural wonders of the world.

"We've seen three bleaching events (in the reef) and each time it can be explained by where the warm water was," the report's author, ARC Center of Excellent for Coral Reef Studies Director Terry Hughes, told CNN.

"In the north, the summer temperatures got up to two degrees above the normal maximum and that caused severe bleaching," he said.

INTERNATIONAL NEWS - Coral across Australia's Great Barrier Reef has suffered its most devastating die-off on record, a new report says. </s> SYDNEY: A mass bleaching event on the Great Barrier Reef this year killed more corals than ever before, scientists said Tuesday, sounding the alarm over the delicate ecosystem.

The 2,300-kilometer (1,400-mile) long reef — the world’s biggest — suffered its most severe bleaching in recorded history, due to warming sea temperatures during March and April, with the northern third bearing the brunt.

Follow-up underwater surveys, backing earlier aerial studies, have revealed a 700-kilometre stretch of reefs in the less-accessible north lost two-thirds of shallow-water corals in the past eight to nine months.

“Most of the losses in 2016 have occurred in the northern, most-pristine part of the Great Barrier Reef,” said Terry Hughes, head of the Centre of Excellence for Coral Reef Studies at James Cook University.

“This region escaped with minor damage in two earlier bleaching events in 1998 and 2002, but this time around it has been badly affected.”

Further south over the vast central and southern regions, including major tourist areas around Cairns and the Whitsunday Islands, there was a much lower toll.

Bleaching occurs when abnormal environmental conditions, such as warmer sea temperatures, cause corals to expel tiny photosynthetic algae, draining them of their colour.

Algae are vital to the coral, which uses the organic products of photosynthesis to help it grow.

The loss of algae makes the host vulnerable to disease and means it will eventually die.

However, coral can recover if the water temperature drops and the algae are able to recolonize them.

Environmentalists blame the burning of fossil fuels for global warming and repeated calls Tuesday for Australia to abandon coal mining to help prevent further bleaching disasters.

“This is the devastating price we are paying for the Australian government propping up the coal industry,” said Greenpeace Australia reef campaigner Shani Tager.

“A credible plan to protect the reef must address climate change and start with a ban on new coal mines.”

Canberra insists it is doing more than ever to safeguard the reef, which is also under pressure from farming run-off, development and the coral-eating crown-of-thorns starfish, committing more than Aus$2.0 billion (US$1.50 billion) over the next decade.

Scientists estimate the northern region, which teems with marine life, will take at least 10-15 years to regain lost corals, but are concerned that a fourth major bleaching event may occur before that, hampering the recovery.

The reef studies center warned earlier this year that if greenhouse gas levels keep rising, similar events would be the new normal, occurring every two years by the mid-2030s.

Given reefs need so long to recover from severe bleaching, it said “we are likely to lose large parts of the Great Barrier Reef in just a couple of decades”.

That study noted climate change had added 1.0 degree Celsius (1.8 degrees Fahrenheit) of warming to ocean temperatures off the Queensland coast in March, when corals were first seen turning white.

There had been fears that the bleaching would badly hurt the tourism industry but Andrew Baird, who led teams of divers to re-survey the reefs in October and November, said the more accessible parts had not suffered as badly.

“The good news is the southern two-thirds of the reef has escaped with minor damage,” he said.

“On average, six percent of bleached corals died in the central region in 2016, and only one percent in the south. The corals have now regained their vibrant color, and these reefs are in good condition.”

Tourism on the World Heritage-listed reef employs 70,000 people and generates Aus$5 billion in income each year.

Australia last year narrowly avoided UNESCO putting the site on its endangered list and must report to the World Heritage committee by December 1 on the progress being made to rescue the reef. AFP </s> The Great Barrier Reef is dying, and there might be zero hope of recovery.

Australia’s Great Barrier Reef is approaching “terminal stage” after two years of consecutive mass coral bleaching, according to scientists who just got back from an aerial survey of the World Heritage site, as reported by Express UK.

Researchers, who recently surveyed the 2,250 km long Great Barrier Reef, said that unusually warm waters caused severe coral bleaching on two-thirds of the reef. The bleaching data on the world’s largest reef was collated after researchers surveyed about 800 individual coral reefs.

A previous survey conducted last year confirmed that two-thirds of corals in the northern section of the Great Barrier Reef are dying due to warm waters caused by global warming.

This year, researchers from ARC Center of Excellence for Coral Reef Studies at James Cook University in Queensland announced that the central part of the reef has been severely damaged following another year of warm climate.

“We’ve had a back-to-back bleaching for the first time,” said Professor Terry Hughes, who directs the center.

“So we redid our aerial surveys again, which was a bit tough. I was hoping to never have to do it again,” Hughes tweeted. “I showed the results of aerial surveys of #bleaching on the #GreatBarrierReef to my students, And then we wept.”

Coral mass bleaching happens when warmer-than-usual waters cause the coral to expel living algae, changing its color to white. Coral bleaching, usually, is no cause for worry since mildly bleached coral can recover itself once temperature drops. Global warming, however, has been keeping the waters warm longer than usual, thus not giving the Great Barrier Reef enough time to recover itself.

“Bleached corals are not necessarily dead corals, but in the severe central region we anticipate high levels of coral loss,” James Kerry, senior research officer at the ARC Center of Excellence for Coral Reef Studies, explains.

This is the fourth time the Great Barrier Reef has suffered mass coral bleaching since 1998.

As previously reported by The Sun, category four Cyclone Debbie, which left a trail of disaster in northeast Australia and New Zealand, could have damaged the Great Barrier Ref even more. The amount of damage the storm left in its wake is still unknown at this point, but scientists said it could range from minor to severe.

Queensland Parks and Wildlife Service and the Great Barrier Reef Marine Park Authority conducted a study last week to determine the extent of the damage and have found destroyed coral at famous snorkeling spots.

“The feedback that’s coming back is the more sheltered areas have come out a bit better, but they all seem to have suffered some form of damage,” Association of Marine Park Tourism Operators’ Brendon Robinson said.

Professor Hughes said that the Great Barrier Reef is not considered dead yet, but it’s going there if no concrete action plan is made to salvage the site.

“Clearly the reef is struggling with multiple impacts. Without a doubt the most pressing of these is global warming,” he said.

Hughes reminded Australia to take decisive action in saving the reef since tourists are spending £3.15 billion each year to pay the tourist attraction a visit. </s> An unprecedented amount of coral bleaching for two consecutive years has severely damaged two-thirds of Australia’s Great Barrier Reef, aerial surveys have shown.

Scientists at the ARC Centre of Excellence for Coral Reef Studies recorded severe coral bleaching for the second time in 12 months after surveying the Great Barrier Reef’s entire 2,300km-long (1,500) miles ecosystem.

“This is the fourth time the Great Barrier Reef has bleached severely – in 1998, 2002, 2016, and now in 2017. Bleached corals are not necessarily dead corals, but in the severe central region we anticipate high levels of coral loss,” said Dr. James Kerry of James Cook University. 



“It takes at least a decade for a full recovery of even the fastest growing corals, so mass bleaching events 12 months apart offers zero prospect of recovery for reefs that were damaged in 2016.”

READ MORE: Australia’s Great Barrier Reef on brink of collapse - scientists

The study found that while the northern third of the reef experienced the most severe bleaching last year, the middle third experienced the most intense coral bleaching this year, resulting in catastrophic damage of the natural wonder of the world.

“The combined impact of this back-to-back bleaching stretches for 1,500km (900 miles), leaving only the southern third unscathed,” said Prof. Terry Hughes who undertook the aerial surveys in both 2016 and 2017.

“The bleaching is caused by record-breaking temperatures, driven by global warming. This year, 2017, we are seeing mass bleaching, even without the assistance of El Niño conditions.”

The 2017 survey of the reef covered more than 8,000km (5,000 miles) and nearly 800 coral reefs that matched the 2016 aerial surveys. Last year, Climate Central found bleaching has hit 93 percent of the reef, with 80 percent enduring severe bleaching.

READ MORE: Viral spiral: 'Obituary' for embattled Great Barrier Reef slammed for hyperbole

The mass bleaching, coupled with the destructive Tropical Cyclone Debbie in March, has struck a previously undamaged section of the reef.

“Clearly the reef is struggling with multiple impacts,” explains Prof. Hughes. “Without a doubt the most pressing of these is global warming. As temperatures continue to rise the corals will experience more and more of these events: 1°C of warming so far has already caused four events in the past 19 years.”

“Ultimately, we need to cut carbon emissions, and the window to do so is rapidly closing.” </s> A new study has found that higher water temperatures have ravaged the Great Barrier Reef, causing the worst coral bleaching recorded by scientists.

In the worst-affected area, 67% of a 700km swath in the north of the reef lost its shallow-water corals over the past eight to nine months, the Australian Research Council Centre of Excellence for Coral Reef Studies based at James Cook University study found.

“Most of the losses in 2016 have occurred in the northern, most-pristine part of the Great Barrier Reef,” Prof Terry Hughes said. “This region escaped with minor damage in two earlier bleaching events in 1998 and 2002, but this time around it has been badly affected.”

The southern two-thirds of the reef escaped with minor damage, Hughes said. This part was protected from the rising sea temperatures because of cooler water from the Coral Sea.

Scientists expect that the northern region will take at least 10 to 15 years to regain the lost corals but are concerned a fourth bleaching event could interrupt the slow recovery.

The dire assessment of the reef’s health comes as the Australian government is due to report to Unesco’s world heritage committee on its handling of the reef.

After the federal government submits the report Unesco will decide whether to again consider listing the Great Barrier Reef on its “list of world heritage in danger”.

The government will need to report on how it has funded and implemented its Reef 2050 long-term sustainability plan, as well as how the bleaching event has affected the reef.

Since it last considered including the Great Barrier Reef on its list, the reef has undergone the worst bleaching event in recorded history. According to government agencies, 22% of the reef was killed in one hit, as unusually warm waters bleached and killed the coral.

Climate change poses such a threat to the reef that the former head of the Great Barrier Reef Marine Park Authority has called for a ban on all new coalmines in Australia to protect the reef from climate change.

Graeme Kelleher, who was the first chief executive of the authority, a position he held for 16 years, said: “Australia cannot have a healthy Great Barrier Reef and a continuing coal industry.

“I love the reef and I have worked to preserve it since 1979; I will oppose anything that threatens to destroy it,” he said. </s> In just nine months, bleaching caused by warmer water has killed around 67% of the coral in a previously pristine part of the reef, one of the natural wonders of the world.

"We've seen three bleaching events (in the reef) and each time it can be explained by where the warm water was," the report's author, ARC Center of Excellent for Coral Reef Studies Director Terry Hughes, told CNN.

"In the north, the summer temperatures got up to two degrees above the normal maximum and that caused severe bleaching," he said.

Extensive aerial surveys and teams of divers were used to map the bleaching, which covered a length of 700 kilometers.

Hughes said it could take up to 15 years for coral to grow back to previous levels. Read: Can our oceans be saved from environmental ruin? Threats to the reef have become so severe that in recent years UNESCO has suggested it could be placed on list of World Heritage sites "in danger." A spokesman for Australia's Environment Minister Josh Frydenberg said a report on the status of the Great Barrier Reef to UNESCO was due by Friday, local time. A decision on whether or not the reef will be declared "in danger" is expected within the next year, the spokesman added. Two major coral bleaching events in the Great Barrier Reef took place in 1998 and 2002, but Hughes said this year's had been the most devastating. "It's quite sobering, we've now seen three of these events, each one was more severe than the last and these have occurred with less than one degree of global warming," he said. "Two degrees of global warming will mean these events are more severe." Dramatic coral bleaching, seen in Australia's Great Barrier Reef from March 2016. Some of the bleaching of reefs in the northern section has been described as "extreme." Bleaching occurs when the marine algae that live inside corals die. Of the reefs surveyed in the northern third of the Great Barrier Reef, 81% are characterized as "severely bleached." "At some reefs, the final death toll is likely to exceed 90%," Andrew Baird, of the ARC Center of Excellence for Coral Reef Studies, says. A photo taken on September 22, 2014, shows bleached coral on the Reef, a key Australian tourist attraction. Tourism on the Great Barrier Reef generates an annual income of A$5 billion ($3.9 billion) and employs nearly 70,000 people. Of the reefs surveyed in the northern third of the Reef, 81% are characterized as "severely bleached." Driven by ocean temperatures that have been 1-2 degrees Celsius (1.8-3.6° F) above average, the bleaching event has left large sections of coral drained of all color and fighting for survival. The Reef has suffered two mass bleaching events, in 1998 and 2002, but the extent of the bleaching in these years was less severe than in 2016. Although the coral is expected to regrow, Hughes said a fourth or fifth major bleaching event in the next 15 years could damage the reef even further. "It's too unpredictable for anyone to be sure when the next event will occur," he said. RELATED: The Great Barrier Reef is not actually dead Researcher Grace Frank completing bleaching surveys in November along the less-damaged southern Great Barrier Reef. Northern reef used to be 'pristine' While the northern parts of the reef were damaged severely by the bleaching event, others survived almost entirely intact. The Great Barrier Reef's southern third only suffered about 1% bleaching on average, the report said, mostly due to the arrival of Cyclone Winston in February this year. "It brought temperatures in the bottom half of the reef down and saved it from what would have been a reef-wide bleaching event," Hughes said. – 

Pictured: A solitary bear sits on the edge of one of the Barter Islands, Alaska. There is no snow, when at this time of year, there should be," wrote photographer Patty Waymire. Via National Geographic The "Climate Change -- In Focus" exhibition shows the effects of climate change.Pictured: A solitary bear sits on the edge of one of the Barter Islands, Alaska. There is no snow, when at this time of year, there should be," wrote photographer Patty Waymire. Via National Geographic Your Shot – The exhibition shows the best 100 photographs from a global competition.

"On a recent trip to Indonesia we were saddened to see the huge number of bleached anemones. We expected to see some coral bleaching, but we were surprised by how many anemones were also becoming victims to rising ocean temperatures," wrote photographer Diana Paboojian. Via National Geographic Your Shot Emperors at the edge in Antarctica – Photo: Kira Morris. A group of emperor penguins faces a crack in the sea ice, near McMurdo Station, Antarctica. Via National Geographic Your Shot – Photo: Jetje Japhet, South Africa. "These animals have found the secret stash of the orange farmer who dumps the oranges that have fallen from his trees at least 7km away from the orchards to control the breeding of fruit fly. It is the end of a long, dry, winter exacerbated by global warming which makes the winters longer and drier and the summers hotter with less rain in an already dry climate. These animals then behave totally out of character with baboons and warthog still feeding after dark," wrote Japhet. Via National Geographic Your Shot – A seal lies near among massive cracks in the sea ice near Ross Island, Antarctica. Photo: Kira Morris, Antarctica. Via National Geographic Your Shot – Photo: Probal Rashid. "A flood-affected woman on a raft approaches a boat, searching a dry place to shelter herself in Islampur, Jamalpur, Bangladesh. Bangladesh is one of the countries most vulnerable to the effects of climate change," wrote Rashid. Via National Geographic Your Shot – Photo: Vladimir Melnik, Russia: "I was in expedition exploring Franz Josef Land archipelago. There was a polar station where people brought dogs as guards against polar bears. The summer is difficult time for bears. In recent years warming in Arctic resulted in loss of sea ice which is critically important for bears as they can hunt only from ice. The bears which stay on the islands doomed to meager ration and go to human settlements," wrote Melnik. Via National Geographic Your Shot – Photo: Ujjal Das, India: "The pic was taken in Puruliya District of West Bengal. This is a drought-prone area and in summertime the whole district becomes dry creating water problem." Via National Geographic Your Shot – Matuf Ikhsan, Indonesia: "In Gers, France, an irrigation reservoir supplies water to a monocultural field. Here the economy revolves mainly around culinary tourism." – Riddhima Singh Bhati, India: "This part of Rajasthan is badly affected by intense heat waves and dryness because of decreased precipitation. The anticipated rise in temperature due to climate change poses formidable challenge to development of livestock in India." – Photo by Hira Ali, Pakistan: "The picture shows a flooding in the mountainous area of Chitral, in the north of Pakistan. There are many glaciers high in the mountain. Due to climate change, for the past two years there has been a lot of flooding and destruction." – Photo: Leung Ka Wa, China: "A visible aspect of climate change is the turbidity in the air. It can be caused by particulates caused by combustion products. The turbid air decreases visibility so it is harder to see the stars in urban areas." – Photo: Tom Schifanella, USA: "Since 2000, Icelandic glaciers have lost 12% of their size, in less than 15 years. Pictured here, Icelandic guide Hanna Pétursdóttir admires an ice cave inside the Svínafellsjökull Glacier, which she notes is rapidly expanding due to the effects of global warming," wrote Schifanella. Via National Geographic Your Shot – Photo: Stuart Chape, Samoa: "This aerial view of the Chong Kneas floating village on Tonle Sap lake, Cambodia, demonstrates just how threatened the great lake is from changing rainfall patterns and rising temperatures." Via National Geographic Your Shot – Photo: Long Yat Chau, Hong Kong: "Air pollution, particularly in the form of waste gas from generating stations, is a serious problem in Hong Kong." – Photo: Ryan Lai, Hong Kong: "Piles of solid waste lie behind a perfectly-framed photograph of spectacular scenery." – Photo: Felicia Hou, USA: "It is almost as if Mother Nature is sending us a warning that if we do not stop destroying the planet now, there may not be one to destroy in the future." – Photo: Vadim Balakin, Russia: "These polar bear remains have been discovered at one of the islands of Northern Svalbard, Norway. While it is not certain whether the polar bear died from starvation or old age, the good condition of its teeth indicate that it is most likely from starvation," wrote Balakin. Via National Geographic Your Shot Hughes said the northern sections had previously been among the most pristine in the entire Great Barrier Reef, remaining untouched while the southern regions saw their coral drop by half in the past 30 years. "It's hard to get to, so it's the part where there are more sharks, more crocodiles, more turtles, more coral. Unfortunately the 67 per cent loss we've detected means that pristine northern part is now in a worse condition than the lower part," he said.
Scientists say warm seas around Australia's Great Barrier Reef have killed two-thirds of a 435-mile stretch of coral in the past nine months.