Scientists say reef preserves are needed

By Jan TenBruggencate
Advertiser Science Writer

Coral reef preserves are needed in critical spots around the globe to protect reef resources from a naturally occurring phenomenon known as "coral bleaching," say marine scientists who met in Honolulu.

In a recent report, scientists called for reef reserves in places where bleaching is least likely to occur.

In a worst-case scenario, protected reefs could provide seed material for the transplanting of corals into areas where they have been killed out by bleaching, said Bishop Museum research zoologist Steve Coles, who helped write the report titled "Coral Bleaching and Marine Protected Areas."

Coles was one of 12 scientists invited to a workshop earlier this year at Bishop Museum to consider what could be done about bleaching.

The sessions were sponsored by The Nature Conservancy and the report was released by the Conservancy and the World Wildlife Fund. (A copy of the report is available on the Web at www.conserveonline.org.)

Reef-building corals are made up of tiny animals and plants living together and helping feed one another. Coral bleaching occurs when corals are under stress, and the plants, called zooxanthellae, leave or are ejected. The coral animals, which generally get their color from the plants, appear pale and begin to starve.

Bleaching can result from excess heat in the water, often the result of sunny, windless conditions when the reefs are not flushed with cooler water from the deep.

Coles said specific reefs should be identified in the Caribbean, Indian Ocean and the Pacific where there are cool upwellings and other conditions that suggest the corals there will avoid bleaching episodes.

The reserves would be managed to protect such reefs from additional stress factors such as the use of dynamite and chemicals in fishing, and sedimentation from runoff.

Coles said Hawai'i has been somewhat protected from bleaching, although it has occurred, notably in Kane'ohe Bay in 1995.

But he said research already planned on Hawai'i reefs, particularly in the Northwestern Hawaiian Islands, could be critical in helping provide science with the information needed to protect reefs in the future.