The steamy days, warm water and mostly tranquil seas of summer make this an idyllic season for divers to explore the wonders of the Florida Keys' coral reef tract. But for the coral polyps that build, populate and paint the reef with color, it's a stressful time.
Under environmental stress, the coral sometimes evicts or digests its symbiotic algae, called zooxanthella, resulting in coral bleaching. The algae is what provides the coral with photosynthesis and color. Coral bleaching is like an immune system deficiency for coral -- it becomes vulnerable to disease -- and prolonged bleaching can prove fatal.
Scientists from Mote Marine Laboratory and the Florida Keys National Marine Sanctuary coordinate a network of "citizen scientists" to help them monitor the seasonal phenomenon.
In 2005, the agencies launched a coral bleaching monitoring program called BleachWatch, with the goal of informing sanctuary officials when and where reefs are undergoing bleaching. The program is funded by the sanctuary and managed by Mote.
"BleachWatch observations play a critical role in early detection of coral stressors," said sanctuary Superintendent Sean Morton. "Through citizen scientist programs like BleachWatch, volunteers have the opportunity to help resource managers better understand and respond to threats to coral reefs."
Bleaching is most frequently associated with elevated water temperatures, usually 88 degrees or higher for prolonged periods. It also can occur when water temperatures dip below the 60-degree threshold. In January 2010, the Keys experienced the first cold-water bleaching event in more than 30 years when water temperatures dipped to 52 degrees for about a week.
Bleaching also can be caused by pollution, increased sedimentation, extremes in salinity, low oxygen, disease and predation.
Water temperatures throughout the Keys are now averaging about 85 degrees, according to the National Weather Service's Key West office. With several more months of hot, windless days ahead, the sanctuary and Mote have scheduled the first BleachWatch volunteer training of the summer. It will be at 7 p.m. Thursday at the Florida Keys Eco-Discovery Center, 35 East Quay Road, Key West.
Training participants will learn how to identify different species of corals and detect signs of bleaching. Trained BleachWatch volunteers are asked to report their observations of both healthy and stressed coral after diving or snorkeling Keys reefs. Those observations may be submitted via fax, mail, email or online.
For more information about the BleachWatch program, visit http://isurus.mote.org/Keys/bleaching.phtml or contact BleachWatch Coordinator Cory Walter at 305-745-2729, ext. 301.