GCRA  OVERVIEW  FAQ  NEWS  ARTICLES  PHOTOS  REEF ISSUES  RESTORATION  PAPERS  LINKS 

CORALS IN PERIL AS REEFS SUFFER WORLDWIDE

USA TODAY, 10/19/1998

Kathryn Winiarski

Coral reefs worldwide are bleaching and dying in record numbers, experts say, because of warmer-than-normal water temperatures.

Severe coral bleaching, which occurs when the limestone skeleton turns white and the tiny coral animals die, was recorded this year in at least 50 countries.

Marine biologists say that hardly a reef ecosystem on the globe was unscathed — from Australia’s Great Barrier Reef to the Seychelles in the Indian Ocean and from Belize in the Caribbean to the U.S. Virgin Islands.

A continuing, large-scale decline of reefs could mean economic trouble for millions of people who rely on the beautiful limestone formations to support fishing grounds, attract tourists and protect shorelines from waves and storms.

“These corals are dying from heatstroke,” says Thomas Goreau, president of the New York-based Global Coral Reef Alliance.

While most people have little concept of the problem because the coral is under water and out of sight, the US. Coral Reef Task Force, established by President Clinton in June, is expected to present plans for preserving coral reefs at a meeting this week in Key Biscayne, Fla.

The administration has requested about $6 million through 2002 to help restore damaged reefs overseen by the United States in the Atlantic, Caribbean and Pacific.

“It is estimated that two-thirds of the world’s coral reefs are dying, and that is why this meeting and initiative are so important:’ says D. James Baker, administrator of the National Oceanic and Atmospheric Administration (NOAA).

Corals that have thrived for hundreds of years suddenly died in 1998, according to a report to be released Nov. 19 by Reef Check, an international coral assessment program. Divers surveying reefs throughout the tropics found that up to 90 percent of some species of coral were dead. Before the 1980s, wide-scale bleaching was not even observed.

The world’s reefs have faced plenty of threats before. They are besieged by overfishing, destroyed by boat anchors and killed by dynamite and cyanide used to capture fish for aquarium hobbyists. Reefs also are routinely battered by storms and by divers, and subjected to disease, pollution and predation.

But high ocean temperatures inflict damage on a more global scale. They cause the microscopic plants that live in coral tissue to stop functioning. The zooxanthellae provide corals with color, food and most of their ability to rapidly grow skeletons. Without them, corals can die.

“The analogy I use is, you keep a starving individual without food for a long enough time, and they’re going to die:’ says Raymond Hayes, an anatomy professor at Howard University and vice president of the Association of Marine Laboratories of the Caribbean.

This year brought the hottest sea-surface temperatures since 1982, according to NOAA satellite data.

At first glance, severe El Nino warming events, which took place both years, appear to bear some blame. But bleaching also took place in regions not affected by El Nino.

Scientists such as Goreau and Hayes blame global warming. They say reefs will rebound only through dramatic reduction of fuel consumption.

In global warming—a phenomenon that remains doubted in some scientific camps — the burning of fossil fuels emits excessive carbon dioxide, trapping heat around Earth like a thick blanket. Representatives from more than 150 countries will meet in Buenos Aires, Argentina, next month to continue work on an emissions reduction treaty that was begun in Japan in 1997.

Other scientists say that warming of ocean waters could just be the result of nature’s unpredictable flux.

“We all hope that this is a severe one-time event:’ says Gregor Hodgson, founder of Reef Watch and a coral ecologist at the Hong Kong University of Science and Technology. “If global warming is involved and the bleaching will be repeated, then we are in very serious trouble.” Corals recover from bleaching only if the waters do not stay too hot for too long.

Alma Szmant of the Coral Reef Research Group at the University of Miami says she is encouraged that some Florida reefs showed early signs of recovery in September.

Meanwhile, the coral reef task force is expected to pursue simpler solutions to reef troubles: reducing the numbers of vessels that slam into reefs is, educating divers against touching coral and creating reef patrols that would be strategically stationed in U.S. waters.

But “it will all come to naught, unless we get a firm grip on the global warming problem,” Interior Secretary Bruce Babbitt says. “Every nation in the world has a stake in getting it done.”

Time may be running out.

NOAA says that at least 10% of the world’s coral reefs already are destroyed, and some experts say the number is much higher.

Reefs also are increasingly subjected to emerging diseases that kill corals at rates not thought possible, says marine biologist James Cervino of the University of South Carolina.

Under current conditions, death could claim 40% of the world’s coral reefs by 2028.

Scientists are now waking us up to the threat.” Babbitt says. “There is a crisis.”

 The Death of a Coral Reef

Related to jellyfish and sea anemones, corals are small animals with limestone skeletons and a skin-like inner lining where tiny plants called zooxanthellae live. They provide corals with food, their brilliant colors and most of their rapid skeleton growth.

Rising water temperatures can kill coral beds

When water temperatures rise beyond a coral’s tolerable limits, corals experience “heat shock.” This causes the zooxanthellae to stop functioning, Corals “bleach” - turn white – and are unable to grow or reproduce.

If the temperature continues to rise and stays warm for extended periods, the coral dies, eventually crumbling under the forces of waves and winds. Shorelines are left unprotected and reef fish lose their habitat.