Bleaching Becoming Epidemic on Great Barrier Reef, The Advertiser, 02/02/06
By: Roberta Mancuso
Article Source: The Advertiser
Blanched coral wastelands could soon become new dive attractions as the Great Barrier Reef teeters on the brink of widespread bleaching.
It's one more marketing approach being considered by worried Queensland tourism operators amid continuing threats to the world's largest tropical coral reef system.
A new threat this week came in warnings of another devastating coral bleaching event after scientists discovered a wasteland of white corals in the Keppel Islands off the central Queensland coast.
Professor Ove Hoegh-Guldberg, chairman of the Bleaching Working Group, said after four months of warmer sea temperatures, readings were now similar to those experienced between 2001 and 2002 when the Great Barrier Reef suffered its worst coral bleaching event.
Up to 60 per cent of the reef – which is the size of about 70 million football fields – was bleached. Between five to 10 per cent was seriously damaged.
"Across the Great Barrier Reef I think it's inevitable," Prof Hoegh-Guldberg said of another bleaching event.
"I guess the amount of heat that's now in the ocean, it's very hard to dissipate and we'd have to have extremely stormy weather for almost the entire rest of the summer to be able to mix the water column and bring the temperatures down.
"I think at this point a couple of weeks of clear and sunny weather would be all you needed to push most of the corals on the southern Great Barrier Reef over."
Corals in the Keppels now had a "glowing white aura".
"In many ways it's quite beautiful," Prof Hoegh-Guldberg lamented. "Some of the tour operators have suggested it should be a dive destination when it (the bleaching event) happens."
Coral bleaching is caused by higher than average water temperatures linked with global climate change.
Corals will expel microscopic plants that live inside coral polyps that provide food and colour, revealing their white calcium carbonate skeletons. They die within about a month if waters do not cool.
"Bleaching occurs when you get to temperatures around 29 degrees," Prof Hoegh-Guldberg said.
"We're starting to get into very dangerous territory where what we see perhaps this year will become the norm and of course extreme events will become more likely.
"The climate is changing so quickly that coral reefs don't keep up, and of course the loss of that ecosystem would be tremendous."
Credible projections have suggested the reef could be wiped out in as little as 30 years because of global climate change.
More optimistic predictions put the figure at 70 years.
Col McKenzie, a dive operator who represents the Association of Marine Park Tourism Operators, said the reef's $5.3 billion tourism industry was alarmed at early bleaching in the Keppels.
"Tourism operators are keeping a very, very close eye on it," he said.
"We can't accept the fact that we might lose the whole Barrier Reef in the next 20 to 30 years through coral bleaching."
The future of the reef looked dim after British Prime Minister Tony Blair last week warned the threat posed by climate change may be greater than previously thought.
He warned in a government-commissioned report that the emission of greenhouse gases, associated with industrialisation and economic growth, was causing global warming at an unsustainable rate.
The report's stark conclusion – too little is being done to stem climate change.
Australian Conservation Foundation executive director Don Henry said the Federal Government had to sign the Kyoto Protocol, which calls on countries to cut greenhouse emissions by 5.2 per cent below 1990 levels by 2012.
"Ignoring this message will come at great cost to the Great Barrier Reef environment, our tourism industry and our national identify," Mr Henry said.
But some scientists say there is hope.
The Townsville-based Australian Institute of Marine Science (AIMS) have discovered some corals may be able to protect themselves from bleaching events by adapting to climate change.
"We have found that corals have the ability to change the type of algae they associate with and that this alters their thermal tolerance," AIMS scientist Ray Berkelmans said.
"We believe this may be at least part of the reason why the Keppels are able to bounce back from a heat wave that had dire consequences for other regions."
Photo Credit: AAP