Nuclear imaging is being used to study a microbe that has devastated an estimated 30 percent of the world's coral reefs, scientists in South Carolina say.

The technology, similar to magnetic resonance imaging, MRI, scans, is being used to study the metabolic activity of Vibrio coralliilyticus, a ocean-dwelling bacterium, scientists at Hollings Marine Laboratory, Charleston, S.C., said.

At temperatures above 75 degrees Fahrenheit, V. coralliilyticus becomes virulent and dislodges zooxanthellae, a photosynthesizing algae that lives within coral tissue, supplying coral with energy and vivid color, the laboratory said in a release Friday. Without zooxanthellae, coral reefs bleach and die.

Nuclear imaging allows the scientists to track three compounds -- betaine, glutamate and succinate -- that regulate energy production in V. coralliilyticus. Tracking changes in the compounds may help determine why temperature change turns non-virulent V. coralliilyticus into a coral killer, the laboratory said.