February 7, 2011

Great Barrier Reef Battered By Cyclones And Flooding

Tropical Cyclone Yasi, a severe, top-category storm, ripped through Australia's northeast tourist coast Thursday, leveling houses and decimating crops as it hit land near the city of Cairns, gateway to Australia's Great Barrier Reef. The reef could face a slow recovery after recent flooding spewed toxic waste into its pristine waters.

Marine experts say it is too early to assess the extent of the damage but the world's largest living organism, the sprawling coral structure, was very likely harmed by Yasi's blistering 180 mile per hour winds.

Stretching for 133,000 square miles off Australia's northeast coast, the Great Barrier Reef was already suffering after last month's record flooding washed a mucky cocktail of debris, sediment, pesticides and other run-off out to sea.

"Cyclones do damage reefs," Nick Graham, a senior research fellow at James Cook University, told AFP. "They tend to be particularly damaging in shallow waters, so they can break corals and kill areas of live coral, so you get a reduction of coral cover.... And that then can have a knock-on effect," Graham continued.

There have been 55 cyclones that have passed over the reef between 1969 and 1997 according to a recent study -- but warming and acidification of the ocean linked to climate change have both increased their frequency and left corals more vulnerable.

"What normally would have recovered in the past in many other places in the world takes a long time because the reefs are not optimal; they don't have a lot of resilience," said Professor Ove Hoegh-Guldenburg, Director of Queensland University's Global Change Institute, to AFP.

"The second thing that is happening is that as we heat the oceans through global warming, we are increasing the frequency of mega cyclones like Yasi.... which potentially, given (the) circumstances, can have really big impacts on coral reefs, reducing their ability to bounce back."

Cyclones such as Yasi have turned reefs to rubble and cause severe damage on living corals. According to the Great Barrier Reef Marine Park Authority, smashed fragments have already begun washing up on Australian beaches. Recovery of the reef is estimated to take 10 years.

"I think probably more damage is being done (to the reef) by the rising temperature in the ocean which is causing the cyclone, as well as the reef to be damaged," says John Merson, from the University of New South Wales, to AFP.

"The other question is the complete lack of attention being given to the fact that we have a category five cyclone because we have climate change, yet we completely ignore this factor in the whole thing. The same thing -- the heating of the water -- is going to increase coral bleaching which will knock out the reef in the long term anyway."


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