April 23, 2009

Australia’s Great Barrier Reef Escapes Death

Scientists reported Thursday that a section of Australia's Great Barrier Reef - in danger of being killed by global warming within mere decades - has regenerated itself in record time.

This partial regeneration is perhaps more appropriately being referred to as a mere "lucky escape" by the head of research for the authority that preserves the World Heritage-listed reef, Laurence McCook.

Due to global warming, this expanse of badly damaged coral at Keppel Island began experiencing an increase in sea temperatures and acidity, which caused bleaching in 2006 and eventuated in the coral being strangled by seaweed. 

Coral bleaching takes place when the organisms that make up coral die, leaving only the white skeleton of the reef. Re-growth is possible, but takes up to 10 years through the process of "reseeding," when the larvae of a distant reef is carried by currents to populate the damaged area once again.

What is unusual about the survival of this particular reef is the rarity in the combination of circumstances. McCook explains that the Keppel reef actual managed to seed itself from surviving fragmented tissue and had returned to a state of fruition through an "asexual re-growth" in just 12 months.

"This is very unusual because it was a single species of seaweed and it's a species that dies back in winter"¦some of the coral had actually maintained enough surviving tissue that they were actually able to grow much faster than we would normally expect", says McCook.

McCook emphasizes the rarity of such an unusual combination of perfect combinations and that such an event should not be taken for granted.

"If the reefs had been heavily polluted, if the area had been over-fished, if tourism wasn't being well managed, all of those things could lead to the reef failing to recover," he said.

Even though the overall well-being of the Great Barrier Reef may be "relatively good on a global scale," McCook cautions that there still exists a very dire threat due to climate change and various human impacts.

"This is a timely warning of just how serious the damage (can be) that climate change can cause. We had a lucky escape because of these unusual circumstances and that is a rare event," he said.

This reef is prized as the world's largest living organism, stretching for 133,000 square miles off the northeast coast of Australia.

Due ostensibly to the warmer seas and higher acidity, the growth of coral has slowed on the reef at a sobering rate since 1990.


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