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Dec. 6, 2002
John Bluck
NASA Ames Research Center, Moffett Field, Calif.
Phone: 650/604-5026 or 650/604-9000



Low-flying airplanes could scan seas to efficiently determine coral reef health, according to a NASA scientist who will discuss her research Dec. 8 during the fall meeting of the American Geophysical Union in San Francisco.

NASA scientist Liane Guild will discuss “Clues to Coral Reef Health” at 8:30 a.m. PST during a poster session in Hall D of the Moscone Convention Center, San Francisco.

“Coral reefs are the canaries of the ocean,” said Guild, a scientist at NASA Ames Research Center located in California’s Silicon Valley. “Just as miners used canaries in coal mines as an early warning of dangerous conditions, scientists can use coral health as a sensitive indicator of the health of the marine environment.”

“We are comparing the data we collected underwater from healthy coral, stressed coral, dead coral, algae and sand with airborne data,” she said. “We are developing a computer program to take reflected light intensity from coral to predict the condition of coral reefs from aircraft and satellite data. Data that airplanes and satellites collect provide monitoring capabilities over large areas of coral reef.”

Guild is working with scientists from the universities of Arizona, Miami and Puerto Rico on a coral reef research project. The scientists say that their study of corals under healthy and stressed conditions can allow researchers to better assess the impacts of large-scale coral bleaching and disease.

"We dove the Andros Island, Bahamas coastal zone coral reef in July and August, and used an instrument to collect unique measurements of light intensity, or “spectral signatures” reflected from healthy and diseased coral on location," she said. Guild and colleagues are developing methods to determine coral reef health remotely from aircraft in coral reef systems.

Because water acts as a light filter, scientists will gather only the visible (not infrared) light collected from aircraft and satellite sensors. Scientists plan to fly “hyperspectral” instruments that contain many detectors that collect information in the visible light range. These instruments provide the most useful information about coral reef community health from above the sea.

“Our primary emphasis is on Acropora palmata (elkhorn coral), a major reef-building coral, which is prevalent in the study area, but which is suffering from white band disease,” she said.

A. palmata is currently being proposed as an endangered species because its populations have severely declined in many areas of the Caribbean, according to Guild. “In addition to the A. palmata, we have collected data from at least seven other coral types that exist within the study area,” she said.



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