Environment

Great Barrier Reef suffers through worst coral bleaching event on record

Great Barrier Reef suffers thr...
Australia's Great Barrier Reef is experiencing its most severe coral bleaching event on record
Australia's Great Barrier Reef is experiencing its most severe coral bleaching event on record
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The Great Barrier Reef has already experienced mass bleaching in 2002 and 1998
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The Great Barrier Reef has already experienced mass bleaching in 2002 and 1998
Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures
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Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures
Global warming presents a serious threat to the livelihood of reef systems
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Global warming presents a serious threat to the livelihood of reef systems
Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures
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Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures
Global warming presents a serious threat to the livelihood of reef systems
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Global warming presents a serious threat to the livelihood of reef systems
Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures
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Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures
Hughes and his team eyed the reef systems between the city of Cairns and neighboring Papua New Guinea to the north, where vessels and island research stations corroborated their observations
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Hughes and his team eyed the reef systems between the city of Cairns and neighboring Papua New Guinea to the north, where vessels and island research stations corroborated their observations
Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures
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Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures
Australia's Great Barrier Reef is experiencing its most severe coral bleaching event on record
9/15
Australia's Great Barrier Reef is experiencing its most severe coral bleaching event on record
Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures
10/15
Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures
Hughes and his team eyed the reef systems between the city of Cairns and neighboring Papua New Guinea to the north, where vessels and island research stations corroborated their observations
11/15
Hughes and his team eyed the reef systems between the city of Cairns and neighboring Papua New Guinea to the north, where vessels and island research stations corroborated their observations
Australia's Great Barrier Reef is experiencing its most severe coral bleaching event on record
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Australia's Great Barrier Reef is experiencing its most severe coral bleaching event on record
Global warming is hurting Australia's Great Barrier Reef in more ways than one, but a new study has brought to light just how far along the damage might already be
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Global warming is hurting Australia's Great Barrier Reef in more ways than one, but a new study has brought to light just how far along the damage might already be
Hughes and his team eyed the reef systems between the city of Cairns and neighboring Papua New Guinea to the north, where vessels and island research stations corroborated their observations
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Hughes and his team eyed the reef systems between the city of Cairns and neighboring Papua New Guinea to the north, where vessels and island research stations corroborated their observations
Global warming presents a serious threat to the livelihood of reef systems
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Global warming presents a serious threat to the livelihood of reef systems

Scientists have warned that global warming is hurting Australia's Great Barrier Reef, but a new study has brought to light just how far along the damage might already be. An aerial survey of more than 500 coral reefs making up the system has revealed that almost all have suffered severe bleaching, with the researchers labeling it the worst mass bleaching event in the World Heritage Site's history.

Coral bleaching occurs as a result of abnormal sea conditions, such as warmer or colder temperatures. This causes stress on the algae living inside the coral, in turn leading the coral to expel them from their tissue. And because these colorful algae are critical to coral health, their departure leaves the coral withering, white and in danger of dying.

While a range of factors can alter the temperature of the ocean, and the Great Barrier Reef has already experienced mass bleaching events in 2002 and 1998, both the frequency and severity of these events is expected to rise in line with rises in global temperatures. According to the US Environmental Protection Agency, global sea surface temperatures rose at an average rate of 0.13° F (0.07° C) per decade between 1901 and 2014.

Global warming is hurting Australia's Great Barrier Reef in more ways than one, but a new study has brought to light just how far along the damage might already be
Global warming is hurting Australia's Great Barrier Reef in more ways than one, but a new study has brought to light just how far along the damage might already be

Partner this with ocean acidification, another consequence of climate change that is already harming the coral's ability to grow, and global warming presents an ominous threat to the livelihood of reef systems around the world.

"This has been the saddest research trip of my life," says Professor Terry Hughes, convenor of the National Coral Bleaching Taskforce. "Almost without exception, every reef we flew across showed consistently high levels of bleaching, from the reef slope right up onto the top of the reef. We flew for 4,000 km (2,485 mi) in the most pristine parts of the Great Barrier Reef and saw only four reefs that had no bleaching. The severity is much greater than in earlier bleaching events in 2002 or 1998."

Hughes and his team eyed the reef systems between the city of Cairns and neighboring nation of Papua New Guinea to the north, where vessels and island research stations corroborated their observations that most of the reefs in the region are suffering bleaching and that virtually all coral species are affected. How the damage extends beyond Cairns to the south is not yet known.

Hughes and his team eyed the reef systems between the city of Cairns and neighboring Papua New Guinea to the north, where vessels and island research stations corroborated their observations
Hughes and his team eyed the reef systems between the city of Cairns and neighboring Papua New Guinea to the north, where vessels and island research stations corroborated their observations

"Even more concerning, we haven't yet found the southern limit of the bleaching," explains Hughes. "We'll be conducting further aerial surveys this week in the central Great Barrier Reef to identify where it stops. Thankfully, the southern Reef has dodged a bullet due to cloudy weather that cooled the water temperatures down."

These aerial surveys will be complimented by further underwater research, as the scientists work to assess the full extent of the damage and coral death.

"Scientists in the water are already reporting up to 50 percent mortality of bleached corals," says Hughes. "But it's still too early to tell just what the overall outcome will be. We will continue to conduct underwater surveys along the Great Barrier Reef in the coming months as the full impact of this mass bleaching event unfolds."

Source: ARC Centre of Excellence for Coral Reef Studies

5 comments
Robert in Vancouver
If bleaching is being caused by higher water temps caused by global warming, why aren't we seeing sea levels rise? Higher water temps would melt polar ice and sea levels would rise, but it isn't happening. I live a few metres away from the Pacific Ocean and can see the tide marks on the rocks, piers, or sea wall - there has been no change to the tide marks in the 27 years I have lived here.
Myron J. Poltroonian
Nice, one sided, "Climate Change Scare Tactics". However, as the late Paul Harvey would say, "And now, the rest of the story": "Many coral reefs 'bleach' (lose the algae that live in symbiotic partnership with them) when sea temperatures rise, But they also bleach when temperatures fall. That's because the corals partner with the algae best adapted toothier current temperature. When the water warms, they reject their cold-water partners and welcome water-weather friends, and vice versa. that's how they have survived for millions of climate-varied years." -Unstoppable Global Warming (Every 1,500 Years) S. Fred Singer and Dennis T. Avery 2nd edition ©2007/2008 Rowman & Littlefield
Nelson Hyde Chick
By mid century as humanity has grown by billions more the only life on this planet will be us humans, the species we exploit and the pests we can't eradicate. Go anthropocene!
christopher
Get taxpayer dollars for free to go diving in the worlds most beautiful reef? I'm IN! What's the catch? Oh - you have to spin some scare crap to scam governments into the grant money? No problem. I can do that. Where's my thermometer...
srmalloy
Studies performed by the Scripps Oceanographic Institute have found that reefs around remote, isolated islands do not exhibit the coral bleaching found in reefs that are regularly exposed to human activities like chemical dumping, sedimentation from land clearing, pollution, shipping accidents, waste dumping, overfishing, and other human activities. We're still causing it, just not the way that the AGW catastrophists would have you believe.