Ancient Australian reef raises hopes for coral as seas warm

September 2, 2010
This undated photo, received from Professor Colin D. Woodroffe at the University of Wollongong, shows the modern reef at Lord Howe Island, 600 kilometres (400 miles) off southeastern Australia, where a relict coral reef has been discovered about 20 to 25 metres further down. About 20 times bigger than the modern reef, the fossil site flourished between 9,000 and 7,000 years ago.

Australian scientists Thursday said they had discovered a sprawling ancient reef in chilly southern waters which could hold new hope for the future of coral as sea temperatures rise.

Researchers used high-resolution sonar and sophisticated drilling to find the fossil near a living coral site at Lord Howe Island, 600 kilometres (400 miles) off southeastern Australia -- the world's southernmost reef.

Around 20 times the size of the modern reef, the fossil site flourished between 9,000 and 7,000 years ago, before perishing, it is thought, due to an abrupt rise in sea levels linked to melting of the .

Lead researcher Colin Woodroffe said the discovery showed coral had once thrived in the southern waters and might do so again as warms the seas, bleaching and destroying reefs further north.

"As global temperatures warm, the reefs in the tropical areas are increasingly stressed, particularly by coral bleaching, and there's been some suggestions that reefs might be able to expand further towards the poles but not much evidence of that," Woodroffe told AFP.

"Our evidence here is that indeed there was a reef, at this limit, that was much more extensive, and that does look quite promising in terms of the opportunity for the reef to expand again."

Woodroffe, from the University of Wollongong, south of Sydney, said the research showed corals may be able to recolonise south as more tropical habitats became hostile and find "refuge" in reefs usually considered too deep for coral growth.

His team will next take their search 26 kilometres south of Lord Howe Island to Ball's Pyramid, a volcanic remnant that juts spectacularly from the ocean, to see if there was a similar reef there and explore why the fossil reef had perished.

"We'd like to interpret why it is that that reef gave up in the past, (it's) just a hypothesis at this stage that it was the speed of rise," he said.

"But it may be related to temperature changes in the past as well, that's an alternative hypothesis."

Scientists say corals are vital to marine life because they provide habitats for a vast variety of creatures and absorb large levels of poisonous carbon dioxide.

Explore further: Study finds seasonal seas save corals with 'tough love'

Related Stories

Study finds seasonal seas save corals with 'tough love'

November 29, 2007

Finally, some good news about the prospects of coral reefs in the age of climate change. According to a new study by the Wildlife Conservation Society, corals may actually survive rising ocean temperatures in ‘tough love’ ...

Larry's cool change good for reef

March 22, 2006

Cyclone Larry has been a nightmare on land but underwater, it may have helped save the Great Barrier Reef from disaster. University of Queensland coral reef expert Professor Ove Hoegh-Guldberg said Larry's wind had cooled ...

Coral reef was untouched by tsunami

February 23, 2006

Scientists say they've discovered a large coral reef off Thailand that was apparently undisturbed by the catastrophic December 2004 Indian Ocean tsunami.

Ongoing collapse of coral reef shark populations

December 4, 2006

Investigators have revealed that coral reef shark populations are in the midst of rapid decline, and that "no-take zones" -- reefs where fishing is prohibited -- do protect sharks, but only when compliance with no-take regulations ...

Scientists call for coral reef regulations

August 4, 2006

Twenty marine scientists, including prominent Britons, are asking the world's governments to regulate the live fish trade to help protect coral reefs.

Coral stress 'like never in history'

December 13, 2006

Large scale coral die-offs are now occurring more frequently than at any time in the last 11 000 years, according to a new study by Australian-based scientists.

Recommended for you

Mysterious deep-Earth seismic signature explained

November 22, 2017

New research on oxygen and iron chemistry under the extreme conditions found deep inside the Earth could explain a longstanding seismic mystery called ultralow velocity zones. Published in Nature, the findings could have ...

Scientists dispute missing dryland forests

November 21, 2017

Scientists are disputing the possibility that a significant portion of the world's forests have been missed in an earlier accounting of ecological diversity.


Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Sep 02, 2010
the reefs won't adapt, migrate and re-establish an entire ecosystem under the enormous strain of human presence.
not rated yet Sep 02, 2010
Or even under the far more enormous strain of meteor impacts, "snow ball" Earth, or the formation of Large Igneous Provinces?

Giving (wo)mankind a lot more power than she has, eh?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.