New NOAA coral bleaching prediction system calls for low level of bleaching in Caribbean this year

A new NOAA coral bleaching prediction system indicates that there will be some bleaching in the Caribbean later this year, but the event will probably not be severe. NOAA issued the first-ever seasonal coral bleaching outlook this week at the 11th International Coral Reef Symposium in Ft. Lauderdale, Fla.

The system also suggests that there is a risk of widespread bleaching in the Northwestern Hawaiian Islands in August, but little bleaching elsewhere during the northern hemisphere summer.

“The ability to predict coral bleaching events and provide advance warning is critically important to sustaining healthy reefs,” said Tim Keeney, deputy assistant secretary of commerce for oceans and atmosphere and co-chair of the United States Coral Reef Task Force. “When coral reef managers and reef users are alerted, they can mobilize monitoring efforts, develop response strategies, and educate reef users and the public on coral bleaching and possible effects on reef resources.”

The new prediction system uses NOAA experimental sea surface temperature forecasts to develop maps of anticipated coral bleaching severity during the upcoming bleaching season (August to October). While NOAA's Coral Reef Watch Program uses satellite sea surface temperature data to alert managers and scientists around the world of the risk of coral bleaching, the new prediction system includes longer range temperature forecasts up to three-months.

Coral bleaching is associated with a variety of stresses, especially increased ocean temperatures. This causes the coral to expel symbiotic micro-algae living in their tissues – algae that provide corals with food. Losing their algae leaves coral tissues devoid of color, and thus they appear bleached. Prolonged coral bleaching of over a week can lead to coral death and the loss of coral reef habitats for a range of marine life.

A major coral bleaching event occurred in the Caribbean in 2005, resulting in significant coral death in much of the region.

“As global temperatures continue to climb, predicting coral bleaching becomes even more critical,” said C. Mark Eakin, Ph.D., coordinator of NOAA's Coral Reef Watch Program. “Our goal is to issue bleaching forecasts for coral reefs worldwide.”