Fish cruise across a reef of Bonaire in the Caribbean. Experts are surveying the area to better understand the threats to coral reef ecosystems. staff and news service reports
updated 1/24/2008 5:04:34 PM ET 2008-01-24T22:04:34

Experts decked in scuba gear and underwater robots are being deployed in the Caribbean to better understand the multiple threats to the world's coral as part of the International Year of the Reef, the federal government announced Thursday.

The National Oceanic and Atmospheric Administration is spearheading the expedition, with NOAA director Conrad Lautenbacher calling it and other events throughout 2008 part of a "campaign to highlight the importance of coral reef ecosystems and to motivate people to protect them."

Threats include sewage pollution, intensive tourism and, more recently, warming seas tied to climate change.

Since early January, the expedition has been investigating shallow and deep coral ecosystems off the island of Bonaire, part of the Netherland Antilles in the Caribbean.

Divers and robots are surveying some of the most pristine Caribbean reefs to learn why they remain relatively healthy while many others are threatened.

'Twilight Zone' explored
Three robotic "Autonomous Underwater Vehicles" are exploring the "Twilight Zone" — an area 180 to 450 yards deep where little is known about reef systems.

"We believe this is the first science expedition using multiple AUVs to chart Bonaire’s reefs and likely the first to do so on coral reefs anywhere," expedition leader Mark Patterson said in a statement.

“This is important because of scale," the researcher at the Virginia Institute of Marine Science at the College of William & Mary added. "AUVs obtain wide-area data, allowing scientists to pinpoint further investigation."

Warming waters have become an increasing threat to coral, which have an upper limit of temperatures they can tolerate, said Clive Wilkinson, coordinator of the Global Coral Reef Monitoring Network.

CO2's 'Soda water' effect
In addition, added carbon dioxide in the ocean water is creating what Wilkinson called the "soda water" effect — increasing the acidity of the water and making it harder for corals to form their shells.

Video: Help for corals Patterson said that even in Bonaire some effects are being seen.

Bonaire "has been viewed as being a pristine environment," he said. But researchers there have found "troubling factors" including the spread of blue-green algae, which may be killing coral.

"We're seeing more dead and dying coral than we should be," he said, though there are also positive signs such as a return of sea urchins, which had been killed by disease.

The Bonaire expedition runs through Jan. 30 and is being chronicled online at

The Associated Press contributed to this report.


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