Experts Predict Great Barrier Reef Could Be World's 1st Gobal Ecosystem to Collapse

The Great Barrier Reef will be so degraded by warming waters that it will be unrecognizable within 20 years, according Charlie Veron, former chief scientist of the Australian Institute of Marine Science, at a conference in London: “There is no way out, no loopholes. The Great Barrier Reef will be over within 20 years or so. They would be the world’s first global ecosystem to collapse. I have the backing of every coral reef scientist, every research organization. I’ve spoken to them all. This is critical. This is reality.”

After being a highly successful life form for 250 million years, disruptions in the biological and communication systems of coral reefs have been found to be  the underlying cause of the coral bleaching and collapse of reef ecosystems around the world.

Coral reefs form the world's biggest single structure made by living organisms, Australia's Great Barrier Reef, which is visible from outer space (image). The reef is composed of over 2,900 individual reefs and 900 islands stretching for over 3,000 kilometers over an area of approximately 344,400 square kilometers.

An explosion of knowledge is helping to explain why coral reefs around the world are collapsing and what it will take for them to survive. The problems facing coral reefs are still huge, and increasing. They are being pressured by changes in ocean temperature, pollution, overfishing, sedimentation, acidification, oxidative stress and disease, and the synergistic effect of some of these problems may destroy reefs even when one cause by itself would not. Some estimates have suggested 20 percent of the world's coral reefs are already dead and an additional 24 percent are gravely threatened.

Corals, it appears, have a genetic complexity that rivals that of humans, according to research funded in part by the National Science Foundation. Their sophisticated systems of biological communication are being stressed by global change, and are only able to survive based on proper function of an intricate symbiotic relationship with algae that live within their bodies.

"We've known for some time the general functioning of corals and the problems they are facing from climate change," said Virginia Weis, a professor of zoology at Oregon State University. "But until just recently, much less has been known about their fundamental biology, genome structure and internal communication. Only when we really understand how their physiology works will we know if they can adapt to climate changes, or ways that we might help."

Corals are tiny animals, polyps that exist as genetically identical individuals, and can eat, defend themselves and kill plankton for food. In the process they also secrete calcium carbonate that becomes the basis for an external skeleton on which they sit. These calcified deposits can grow to enormous sizes over long periods of time and form coral reefs – one of the world's most productive ecosystems, which can harbor more than 4,000 species of fish and many other marine life forms.

But corals are not really self sufficient. Within their bodies they harbor highly productive algae – a form of marine plant life – that can "fix" carbon, use the energy of the sun to conduct photosynthesis and produce sugars.

"Some of these algae that live within corals are amazingly productive, and in some cases give 95 percent of the sugars they produce to the coral to use for energy," Weis said. "In return the algae gain nitrogen, a limiting nutrient in the ocean, by feeding off the waste from the coral. It's a finely developed symbiotic relationship."

What scientists are learning, however, is that this relationship is also based on a delicate communication process from the algae to the coral, telling it that the algae belong there, and that everything is fine. Otherwise the corals would treat the algae as a parasite or invader and attempt to kill it.

"Even though the coral depends on the algae for much of its food, it may be largely unaware of its presence," Weis said. "We now believe that this is what's happening when the water warms or something else stresses the coral – the communication from the algae to the coral breaks down, the all-is-well message doesn't get through, the algae essentially comes out of hiding and faces an immune response from the coral."

This internal communication process, Weis said, is not unlike some of the biological processes found in humans and other animals. One of the revelations in recent research, she said, is the enormous complexity of coral biology, and even its similarity to other life forms. A gene that controls skeletal development in humans, for instance, is the identical gene in corals that helps it develop its external skeleton – conserved in the different species over hundreds of millions of years since they parted from a common ancestor on their separate evolutionary paths.

There's still much to learn about this process, researchers said, and tremendous variation in it. For one thing, there are 1,000 species of coral and perhaps thousands of species of algae all mixing and matching in this symbiotic dance. And that variation, experts say, provides at least some hope that combinations will be found which can better adapt to changing conditions of ocean temperature, acidity or other threats. The predicted acidification of the oceans in the next century is expected to decrease coral calcification rates by 50 percent and promote the dissolving of coral skeletons, the researchers noted in their report.

"With some of the new findings about coral symbiosis and calcification, and how it works, coral biologists are now starting to think more outside the box," Weis said. "Maybe there's something we could do to help identify and protect coral species that can survive in different conditions. Perhaps we won't have to just stand by as the coral reefs of the world die and disappear."

Dr Veron’s comments came as the Zoological Society of London, the Royal Society and the International Programme on the State of the Ocean (IPSO) held a crucial meeting on the future of coral reefs in London yesterday. In a joint statement they warned that by mid-century extinctions of coral reefs around the world would be inevitable.

Posted by Casey Kazan.

http://earthobservatory.nasa.gov/Newsroom/view.php?id=38862&src=twitter-news

http://www.timesonline.co.uk/tol/news/environment/article6652866.ece

Comments

[nepharous]

Humanity is going to pay dearly for our ways. I fear for my childrens future.

[Mike]

145.5 million years ago during the Jurassic the co2 levels were 700% higher than today. Why is an increase of only 15-30% over the next 100 years going to destroy something that has withstood far more?

[Art]

There is no way out, no loopholes. The Great Barrier Reef will be over within 20 years or so. They would be the world’s first global ecosystem to collapse. I have the backing of every coral reef scientist, every research organization. I’ve spoken to them all. This is critical. This is reality.”
- Charlie Vernon, Australian Institute of Marine Science

Only when we really understand how their physiology works will we know if they can adapt to climate changes.
- Virginia Weis, a professor of zoology at Oregon State University

Am I the only one who sees the contradiction in these two statements? Charlie Vernon insists that "every coral reef scientist" agrees that the Great Barrier Reef will be over in 20 years. Yet, Virginia Weis candidly admits that they do not "really understand how their [coral] physiology works".

Mr. Vernon's screaming sounds rather delusional considering that the end of the Great Barrier Reef is probably one of the most predicted events in modern history.

Here's a story about the spectacular Great Barrier Reef recovery following an El Nino event:

Sections of coral reef in Australia's Great Barrier Reef have made a "spectacular" recovery from a devastating bleaching event three years ago, marine scientists say.

In 2006, high sea temperatures caused severe coral bleaching in the Keppell Islands, in the southern part of the reef — the largest coral reef system in the world...

A "lucky combination" of rare circumstances has meant the reef has been able to make a recovery. Abundant corals have reestablished themselves in a single year, say the researchers from the University of Queensland's Centre for Marine Studies and the ARC Centre of Excellence for Coral Reef Studies (CoECRS).

[...]

"The exceptional aspect was that corals recovered by rapidly regrowing from surviving tissue," said Dr Sophie Dove, also from CoECRS and The University of Queensland.

"Recovery of corals is usually thought to depend on sexual reproduction and the settlement and growth of new corals arriving from other reefs. This study demonstrates that for fast-growing coral species asexual reproduction is a vital component of reef resilience."

Last year, a major global study found that coral reefs did have the ability to recover after major bleaching events, such as the one caused by the El Niño in 1998.

The UK Guardian

Coral reefs are actually very resilient. They have staged remarkable recoveries in Australia, Tanzania and even off the Bikini Islands following the nuclear tests in the 50's. New coral reefs have established themselves in Brazil. Corals became common in the oceans during the Ordovician Era - nearly 500 million years ago - when atmospheric CO2 levels were about 10X greater than they are today.

NASA has confirmed that the worlds oceans are currently cooling. They average pH is approx. 8, which is alkaline not acid and, in any case, it would take thousands of years, not 20, for them to become acidic.

Anyone who starts screaming that the world will end in 20 years belongs on a soapbox outside the local subway station, not in a scientific setting.

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[Jerry]

So? Maybe this is supposed to happen. How many ecosystems have begun and ended since the birth of life on our planet? There was no one around back then to destroy ecosystems, yet they still failed. Why? Was it tragic then? Why is it tragic now? Is it because we believe we are the cause? Are we not part of the natural order? Parts of our planet will die. Other parts will be born. Life adapts. It is the way of things.