SUNS  4339 Monday 7 December 1998



ENVIRONMENT: WARMER OCEANS DESTROYING CORAL REEFS

Washington, Dec. 3 (IPS/Danielle Knight) -- Increased surface temperatures in the world's oceans in 1998 caused the death and "bleaching" of coral reefs across the globe, especially off the coasts
of developing countries, according to the U.S. National Oceanic and Atmospheric Administration (NOAA).

The "unprecedented global bleaching... may have far-reaching negative affects on human health and economies that depend on biodiversity, fisheries, tourism and shore protection provided by coral reefs," James Baker, a NOAA administrator, said Thursday.

"Coral bleaching" is the term for a disease which thrives in warm-water temperatures and causes coral to turn white and eventually die. As ocean surface temperatures increased during  1998 such bleaching had become a common occurrence, he said.

The trend could continue because of the threat of continued global warming. The United Nations Intergovernmental Panel on Climate Change already has predicted further increases in ocean temperatures from the warming of the atmosphere caused by the burning of fossil fuels.

"The bleaching and mortality rate may worsen in the years ahead," said Baker. "This serves as a wake-up call for more research and monitoring to help protect these valuable coral reef ecosystems."

Temperatures in oceans in the Northern Hemisphere had risen one half of a degree Celsius during the past 15 years although there had been no sustained increase in the Southern Hemisphere, said NOAA scientist Alan Strong.

"We don't know exactly what is causing this increase," he said. "This observation was not predicted on any of the climate change computer models and we are all wondering what the ocean is trying to tell us."

The increase in sea-surface temperatures, however, threaten entire coral reef zones, built by tiny animals depositing limestone, which are home to one quarter of all marine plants and animals. Millions of species of fish, crabs, algae and other marine animals live on reefs or use them nurseries to protect their young.

Besides threatening these species, the loss of coral reefs would also hurt the tourism and fishing industry worth billions of dollars each year, mostly to developing countries, said NOAA.

According to a group of marine scientists attending the International Tropical Marine Ecosystem Symposium in Australia - home to the Great Barrier Reef - ocean warming had devastated coral reefs in the Maldives, Sri Lanka, Kenya, and Tanzania and many parts of Southeast Asia.

"Shallow reefs look like graveyards," a NOAA statement declared. "Although the effects are uneven and patchy, the only major reef region spared from coral bleaching appears to be the Central Pacific. In some parts of the Indian Ocean, mortality is as high as 90 percent."

Using satellite images and buoys in coordination with NOAA, scientists said countries the worst hit were Japan, Taiwan, the Philippines, Vietnam, Thailand, Singapore, Indonesia and the island of Palau.

"This will impact the livelihoods of millions of people," said the U.S. agency. Warming trends attributed to human-induced global warming caused by the burning of oil, coal and gas would  further damage these ecosystems, it added.

Earlier this year NOAA and international weather agencies announced that the last decade was the hottest ever recorded, while 1997 was the hottest year and that 1998 was likely to be even hotter.

Global warming trends may lead to more extreme and unpredictable weather and any increase in tropical storms could do extensive physical damage to coral reef ecosystems, said the California-based Coral Reef Alliance, an advocacy group.

Besides global warming, other human activities have already caused the disappearance of 10 percent of the Earth's reefs, said the Alliance. Such activities included increased coastal development, fishing with explosives, and water pollution "If the present rate of destruction continues, 70 percent of the world's coral reefs will be killed within our lifetime," according to
Coral Reef Alliance.

Construction in coastal areas caused soil to erode and rush downstream into the ocean and onto coral reefs. This dirt, silt, or sand made the water cloudy or muddy and smothered the coral which needed light to survive, warned the organisation.

Mangrove trees and sea grasses which normally acted as filters for sediment also were being rapidly destroyed leading to an increase in the amount of sediment reaching coral reefs.

Fertilizers and sewage dumped into coastal waters also destroyed the reefs by encouraging rapid algae growth and cut off the coral's supply of light and oxygen.

Fishing fleets often used cyanide and other poisons to stun and capture valuable reef fish. This method, which spells death for the reefs, is often used to catch tropical fish for aquariums and is now used to capture fish for "live fish" restaurants, said the Alliance.

"In the Philippines, up to 400 thousand pounds of cyanide are sprayed and dumped onto the reefs each year - with the result that less than 10 percent of the coral reefs in this area remain healthy," the group said.