Stressed-Out Corals

To learn more about recent alarming reports of coral die-offs, I contacted Dr. James Cervino of Global Coral Reef Alliance. Here’s what he told me:

“Coral epizootics [widespread disease outbreaks] are on the rise. It is very important to note that this is not simply an isolated case happening to one island; coral diseases are hitting the entire Caribbean. Divers ask me all the time, ‘What’s the best place to go where there’s no disease and pollution?’. Diseases and eutropication can be found at all sites in the Caribbean.

“The coral’s resistance to disease is low because it’s under stress: high temperatures (indicated by widespread bleaching), eutrophication, sedimentation, pollution, salinity changes, storms. Stress lowers coral’s production of mucus, which protects it from sediment and harmful bacteria. Bacteria love to invade coral under stress. I recently cultured mucus samples from a bleached coral and an unbleached coral. The bleached coral had much higher concentrations of bacteria than the unstressed coral.

“I just confirmed rapid wasting disease in the Virgin Islands; it’s hitting hard, and I know it’s just a matter of time till it’s in the Bahamas.

“What can divers do to help? This year and next I’ll be running workshops on coral diseases. This will give divers a chance to get involved with scientists. Soon I’ll be issuing an ID card with all the known diseases in the field to take with you underwater. Report your observations, and send me videos or slides for confirmation.

“We need divers! But most divers are seeing bleaching, not disease. Pictures can help. With photos in hand, we can decide whether it’s worth a trip to collect samples.”

To offer your assistance, contact Dr. James Cervino at cnidaria@earthlink.net.

J. Q.