Coral bleached for two consecutive years at Australia's Great Barrier Reef has "zero prospect" of recovery, scientists warned Monday, as they confirmed the site has again been hit by warming sea temperatures.

Researchers said last month they were detecting another round of mass bleaching this year after a severe event in 2016, and their fears were confirmed after aerial surveys of the entire 2,300-kilometre (1,400-mile) long bio-diverse reef.

WATCH |&nbsp;<a href="https://www.wionews.com/videos/we-need-to-rethink-our-role-on-planet-if-corals-cannot-be-saved-538687">'We need to rethink our role on planet if corals cannot be saved'</a>

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Last year, the northern areas of the World Heritage-listed area were hardest hit, with the middle-third now experiencing the worst effects.

"Bleached corals are not necessarily dead corals, but in the severe central region we anticipate high levels of coral loss," said James Kerry, a marine biologist at James Cook University who led the aerial surveys.

"It takes at least a decade for a full recovery of even the fastest growing corals, so mass bleaching events 12 months apart offer zero prospect of recovery for reefs that were damaged in 2016."

It is the fourth time coral bleaching -- where stressed corals expel the algae that live in their tissue and provide them with food -- has hit the reef after previous events in 1998 and 2002.

"The combined impact of this back-to-back bleaching stretches for 1,500 kilometres, leaving only the southern third unscathed," said Terry Hughes, head of the Centre of Excellence for Coral Reef Studies, also at James Cook University. 
"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 Nino conditions," he added, referring to the natural climate cycle in the Pacific Ocean.

The Barrier Reef is already under pressure from farming run-off, development and the crown-of-thorns starfish.

It was also recently hammered by category four Cyclone Debbie, which barrelled through the region last month, mostly affecting southern parts around the Whitsunday islands which largely escaped the bleaching.

The extent of the destruction wrought by Debbie is not yet known, although scientists have said damage could range from minor to severe.

Queensland Parks and Wildlife Service and the Great Barrier Reef Marine Park Authority began a study last week to determine how extensive it might be and have already found extensive pulverised coral at popular 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'&nbsp;Brendon Robinson told the Australian Broadcasting Corporation.

The Whitsundays is one of the reef's tourist hotspots, attracting more than 40 per cent of total visitors to the iconic marine ecosystem.

Hughes warned rising temperatures could see more bleaching events.

"Clearly the reef is struggling with multiple impacts. Without a doubt the most pressing of these is global warming," he said.&nbsp;

"As temperatures continue to rise the corals will experience more and more of these events. One degree Celsius 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."

The world's nations agreed in Paris in 2015 to limit average warming to two degrees Celsius (3.6 degrees Fahrenheit) over pre-industrial levels, by curbing fossil fuel burning.

Canberra in 2015 narrowly avoided UNESCO putting the reef on its endangered list, and has committed more than Aus$2.0 billion (US$1.5 billion) to protect it over the next decade.

(AFP)

The Barrier Reef is already under pressure from farming run-off, development and the crown-of-thorns starfish

Coral bleached for two consecutive years at Australia's Great Barrier Reef has "zero prospect" of recovery, scientists warned Monday, as they confirmed the site has again been hit by warming sea temperatures. Researchers said last month they were detecting another round of mass bleaching this year after a severe event in 2016, and their fears were confirmed after aerial surveys of the entire 2,300-kilometre (1,400-mile) long bio-diverse reef. WATCH | 'We need to rethink our role on planet if corals cannot be saved' × Last year, the northern areas of the World Heritage-listed area were hardest hit, with the middle-third now experiencing the worst effects. "Bleached corals are not necessarily dead corals, but in the severe central region we anticipate high levels of coral loss," said James Kerry, a marine biologist at James Cook University who led the aerial surveys. "It takes at least a decade for a full recovery of even the fastest growing corals, so mass bleaching events 12 months apart offer zero prospect of recovery for reefs that were damaged in 2016." It is the fourth time coral bleaching -- where stressed corals expel the algae that live in their tissue and provide them with food -- has hit the reef after previous events in 1998 and 2002. "The combined impact of this back-to-back bleaching stretches for 1,500 kilometres, leaving only the southern third unscathed," said Terry Hughes, head of the Centre of Excellence for Coral Reef Studies, also at James Cook University. "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 Nino conditions," he added, referring to the natural climate cycle in the Pacific Ocean. The Barrier Reef is already under pressure from farming run-off, development and the crown-of-thorns starfish. It was also recently hammered by category four Cyclone Debbie, which barrelled through the region last month, mostly affecting southern parts around the Whitsunday islands which largely escaped the bleaching. The extent of the destruction wrought by Debbie is not yet known, although scientists have said damage could range from minor to severe. Queensland Parks and Wildlife Service and the Great Barrier Reef Marine Park Authority began a study last week to determine how extensive it might be and have already found extensive pulverised coral at popular 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 told the Australian Broadcasting Corporation. The Whitsundays is one of the reef's tourist hotspots, attracting more than 40 per cent of total visitors to the iconic marine ecosystem. Hughes warned rising temperatures could see more bleaching events. "Clearly the reef is struggling with multiple impacts. Without a doubt the most pressing of these is global warming," he said. "As temperatures continue to rise the corals will experience more and more of these events. One degree Celsius 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." The world's nations agreed in Paris in 2015 to limit average warming to two degrees Celsius (3.6 degrees Fahrenheit) over pre-industrial levels, by curbing fossil fuel burning. Canberra in 2015 narrowly avoided UNESCO putting the reef on its endangered list, and has committed more than Aus$2.0 billion (US$1.5 billion) to protect it over the next decade. (AFP)

Australia: 'Zero recovery' for corals in back-to-back bleaching

A UNESCO panel has recommended that the Great Barrier Reef be stripped of its World Heritage Site tag. Australia is blaming the China-led panel for settling a political score at UNESCO. Palki Sharma tells you more.

Gravitas: Great Barrier Reef downgraded, Australia blames China

Australia said it will strongly oppose a China-chaired UNESCO plan to list the Great Barrier Reef as a heritage site “in danger” over deterioration caused by climate change.

Australia hits back at China-chaired UNESCO over Barrier Reef's heritage status

Coral bred in one part of the Great Barrier Reef was successfully transplanted into another area, Australian scientists said Sunday, in a project they hope could restore damaged ecosystems around the world.

In a trial at the reef&#39;s Heron Island off Australia&#39;s east coast, the researchers collected a large amount of coral spawn and eggs late last year, grew them into larvae and then transplanted them into areas of the damaged reef.

When they returned eight months later, they found juvenile coral that had survived and grown, aided by underwater mesh tanks.

&quot;The success of this new research not only applies to the Great Barrier Reef but has potential global significance,&quot; lead researcher Peter Harrison of Southern Cross University said.

&quot;It shows we can start to restore and repair damaged coral populations where the natural supply of coral larvae has been compromised.&quot;

Harrison said his mass larval-restoration approach contrasts with the current &quot;coral gardening&quot; method of breaking up healthy coral and sticking healthy branches on reefs in the hope they will regrow, or growing coral in nurseries before transplantation.

He was optimistic his approach, which was earlier successfully trialed in the Philippines in an area of reef highly degraded by blast fishing, could help reefs recover on a larger scale.

&quot;The results are very promising and our work shows that adding higher densities of coral larvae leads to higher numbers of successful coral recruits,&quot; he added.

The Great Barrier Reef, the largest living structure on Earth, is reeling from an unprecedented second-straight year of coral bleaching because of warming sea temperatures linked to climate change.

The chief scientist of the Great Barrier Reef Marine Park Authority, the government agency that manages the area, said there was a need for such efforts amid the accelerating impacts of climate change.

&quot;The success of these first trials is encouraging -- the next challenge is to build this into broader scale technology that is going to make a difference to the Reef as a whole,&quot; David Wachenfeld said.

&nbsp;

Researchers collected a large amount of coral spawn and eggs, grew them into larvae, and then transplanted them into areas of the damaged reef

Coral bred in one part of the Great Barrier Reef was successfully transplanted into another area, Australian scientists said Sunday, in a project they hope could restore damaged ecosystems around the world. In a trial at the reef's Heron Island off Australia's east coast, the researchers collected a large amount of coral spawn and eggs late last year, grew them into larvae and then transplanted them into areas of the damaged reef. When they returned eight months later, they found juvenile coral that had survived and grown, aided by underwater mesh tanks. "The success of this new research not only applies to the Great Barrier Reef but has potential global significance," lead researcher Peter Harrison of Southern Cross University said. "It shows we can start to restore and repair damaged coral populations where the natural supply of coral larvae has been compromised." Harrison said his mass larval-restoration approach contrasts with the current "coral gardening" method of breaking up healthy coral and sticking healthy branches on reefs in the hope they will regrow, or growing coral in nurseries before transplantation. He was optimistic his approach, which was earlier successfully trialed in the Philippines in an area of reef highly degraded by blast fishing, could help reefs recover on a larger scale. "The results are very promising and our work shows that adding higher densities of coral larvae leads to higher numbers of successful coral recruits," he added. The Great Barrier Reef, the largest living structure on Earth, is reeling from an unprecedented second-straight year of coral bleaching because of warming sea temperatures linked to climate change. The chief scientist of the Great Barrier Reef Marine Park Authority, the government agency that manages the area, said there was a need for such efforts amid the accelerating impacts of climate change. "The success of these first trials is encouraging -- the next challenge is to build this into broader scale technology that is going to make a difference to the Reef as a whole," David Wachenfeld said.

Coral transplant raises Great Barrier Reef survival hopes

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Australia: 'Zero recovery' for corals in back-to-back bleaching

Gravitas: Great Barrier Reef downgraded, Australia blames China

Australia hits back at China-chaired UNESCO over Barrier Reef's heritage status

Coral transplant raises Great Barrier Reef survival hopes