Reefs will be dead within 30 years, Australian expert warns

The Australian 1 Sep 08;

THE world's reefs, including Australia's Great Barrier Reef, will be dead within 30 years unless human activity changes quickly, a leading researcher says.
Addressing the 11th international River symposium in Brisbane, Ove Hoegh-Guldberg said it was crunch time for the world's reefs.

“Let's say we delay another 10 years on having stern actions on emissions at a global level, we will not have coral reefs in about 30 to 50 years,” he said.

Professor Hoegh-Guldberg, from the Centre for Marine Studies at the University of Queensland, said rising CO2 levels and melting ice caps meant the ocean was becoming uninhabitable for reefs.

This worldwide change in climatic conditions was in addition to land-based pollution spilling from Queensland's coastal river systems, a symposium session into the impacts of river systems on the reef was told.

“We're rapidly rising to (CO2) levels which will be unsustainable for reefs in the very near future,” Professor Hoegh-Guldberg said.

“If you ask the question, `Will we have coral reefs in 30 years' time?', I would say at the current rate of change and what we're doing to them, we won't. But it's all up to us right now.

“We're at the fork in the road. If we take one road - the one we're on right now - we won't have coral reefs.

“If we make some very, very, very aggressive actions, if we reform how we do things, both at the global and local level, we'll have a really good chance of bringing coral reefs through in some shape or form, which will still provide the basis for the 100 million people that they support.”

He said ice core samples showed CO2 levels were the highest for at least a million years, possibly 20 million years.

“That changes the circumstances under which corals form their skeletons, so they become less vibrant,” Professor Hoegh-Guldberg said.

“Then if you keep hitting them with things like bleaching events, they just don't bounce back as much.

“So we're changing essentially the rules under which biology is trying to operate, and that's the problem.”

He also warned that an increasing incidence of coral bleaching was a growing threat.

“If we have them (bleaching events) now every four to five years, we're getting to a point where reefs no longer have time to recover.”

The impact on Queensland's $6 billion-a-year earnings from reef-based tourism would be enormous, he said.

“So we might have an industry that's half the size, but it certainly won't have the pull that it does today,” he said. AAP

'Crunch time for Barrier Reef'
Tony Moore, Brisbane Times 1 Sep 08;

There are grave doubts that the Great Barrier Reef can continue to attract tourists worth $6 billion-a-year to Queensland, a coral specialist told the International Riversymposium in Brisbane this afternoon.

And there are further doubts the Great Barrier Reef will even survive the next 30 years.

Professor Ove Hoegh-Guldberg said there was no time left to delay the impact of climate change on Queensland's premier 2000-kilometre coral reef.

"It's crunch time," Professor Hoegh-Guldberg said.

"Let's say if we delay a further 10 years on having stern action on emissions at a global level we will not have coral reefs in 30 to 50 years," he said.

He said tourism was adaptable, but Australia's best tourist feature was under attack from climate change.

"Tourism industries are remarkably flexible, but one salient feature of our industry is that we have the best example of a large continuous reef system in the world," Professor Hoegh-Guldberg said.

"And that is what is bringing people in," he said.

"If we don't gave that, then we don't have the same drawcard.

"So we might have an industry that is half the size, but it certainly won't have the same (tourist) pull that it has today."

Professor Hoegh- Guldberg, from the Centre for Marine Sciences at the University of Queensland, said the future of the Barrier Reef depended on what happened next.

"We have C02 levels at 1 to 2 parts per million per year - they are 380 parts per million - and that is significant because they have not been that high for the past 720,000 years," he said.

Until the industrial revolution, atmospheric carbon was around 280 parts per million.

Higher carbon levels means coral colours become less vibrant and more frequent coral bleaching destroys the reefs.

"So if you ask the question will we have coral reefs in 30 years time, then I would say at the current rate of change and what we are doing to them - we won't," he said.

"But it all up to us right now."

He said rising ocean acidity from warmer oceans would also prevent coral reefs being able to form the calcium carbonate they need to form the reefs themselves.

"Ocean acidity, while it doesn't have any really big impacts right upfront now, will become the looming problem of tomorrow," he said.

Coral bleaching has occurred over the past 30 years, but came to public attention in the early 1980s, he said.

"Since then we have had six major episodes of coral bleaching," Professor Hoegh-Guldberg said.

While coral bleaching did happen before the early 1980s, he said reefs had time to recover between incidents.

"If we have them now every four to five years, we are getting to the point were reefs no longer have the time to recover," he said.

"And that is when you start to lose the fish, the million species that lives on coral reefs.

"And that, is what draws tourists to Australia and supports our industries."

He said one major thrust of the International Riversymposium in Brisbane this week was to understand the links between rivers and reefs.