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Study Predicts Complete Loss of World's Coral Reefs

MONITOR Wire Services

about coral bleaching
coral Unless the United States and other industrial countries work quickly to cut pollution from the burning of coal, oil, and gas, a new study warns that global warming may wipe out all coral reefs on the planet within the next few decades.

Professor Ove Hoegh-Guldberg, one of the world's leading experts in coral "bleaching," says that the events that shocked the world's scientific communities last year could become an annual occurrence. 1998 was the warmest year on record, and brought with it the most widespread and severe coral bleaching to date. Every reef system in the world's tropical oceans was affected, and in some places like the Indian Ocean, entire reef systems were destroyed.

Using two widely accepted global climate models, he projected how the frequency and intensity of bleaching events would change over the next 100 years if greenhouse gas emissions were not reduced. Hoegh-Guldberg said the die-off could begin as early as the year 2030.

The researcher said these results were startling and a matter of great concern. "Arguments that corals will acclimate to predicted patterns of temperature change are unsubstantiated, and evidence suggests that the genetic ability of corals to acclimate is already being exceeded," Hoegh-Guldberg warned.

"A single bleaching event will take reefs between 30 to 100 years to recover but, if we go into unrestrained warming when corals will become quite rare on the face of the earth, we'd be looking at quite a long recovery time, up to 500 years," Hoegh-Guldberg also told Reuters.

World map of coral bleaching Coral bleaching can seriously damage or kill entire reef systems. Corals contain microscopic plants called zooanthellae, which create the coral's vibrant colors and also provides a coral with food. When corals become stressed, as from rising ocean temperatures, they expel the zooanthellae and turn white, or "bleach."

Mass coral bleaching is thought to be a new phenomenon that has increased in frequency over the past two decades. Most bleaching events are explained by a one degree Celsius rise in water temperature above the summer maximum.

"The loss of coral reefs would have devastating consequences, adversely affecting millions of people around the world," said Iain MacGill, Greenpeace Climate Issues Specialist. "Coral reefs provide large sources of income for the tourism and fishing industries, ingredients for new drugs and coastal protection from extreme weather events, their loss potentially costing trillions of dollars."

Global Warming: The Oceans in Peril
As if bleaching weren't enough, a report from the World Wildlife Fund notes that new evidence suggests that even the increased levels of carbon dioxide in the atmosphere may be harmful for reefs as it weakens corals' calcium carbonate skeletons and makes them more susceptible to storm damage and other erosion.

Great Barrier Reef One of the most famous coral reefs, the Great Barrier Reef off the Australian coast, is also at risk from decades of human abuse.

Illegal bottom trawlers hoping to catch prawns regularly damage the reef, according to a report issued by Commonwealth Scientific and Industrial Research Organization (CSIRO) earlier this year.

A single pass of a trawler can remove up to 25 per cent of seabed life, according to the report.

Although the illegal fishermen risk fines of up to $1 million, Australia does not have the resources to patrol the immense reef, which covers more than 130 thousand square miles.

Ships also routinely discharge oil and waste in the area illegally and use the pristine ocean water near the reef to wash coal and iron ore residue from their decks.

The Australian military was also criticized in January when it was revealed that the Royal Australian Air Force was still using part of the reef for bombing practice.

The managing Great Barrier Reef Marine Park Authority has been criticized for downplaying the condition of the reef, insisting in their annual "State of the Great Barrier Reef World Heritage Report" that overall the reef was in good shape, and good hands. Environmental groups, gowever, are asking the UN to list the World Heritage Are as a "World Heritage In Danger."

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Albion Monitor July 12, 1999 (

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