The NOAA Coral Reef Watch (CRW) Coral Bleaching Thermal Stress Outlook
indicates that there is a high potential for coral bleaching in the
Caribbean in 2010. The 2009-2010 El Niño ended in May 2010. However,
the Caribbean usually experiences elevated temperature during the year
following an El Niño event. Since the beginning of 2010, sea surface
temperatures (SSTs) in most of the Caribbean region and tropical Atlantic
Ocean have been observed more than 1ºC above the normal (see the SST
anomaly figure above), based on Coral Reef Watch's climatology. This
pattern is similar to, but has persisted much longer than, what occurred
during the same time period in 2005. In 2005, a record breaking mass coral
bleaching event in the Caribbean along with the most active hurricane
season on record in the Atlantic Ocean followed such a pre-bleaching season
SST anomaly pattern. The high SST anomaly in the Gulf of Mexico and Florida
Keys began in mid-May after a dramatic increase in SST in early May (near
2ºC increase over several days at some locations) after an extreme cold
outbreak earlier this year in the eastern Gulf of Mexico and Florida area.
This preheating increases the likelihood that temperatures will exceed
bleaching thresholds during the coming season. The pattern and intensity of
early-season SST anomalies is similar to what was seen in 2005. The high
potential for thermal stress above levels required to cause bleaching as
seen in the CRW bleaching outlook system indicates a high potential for
significant bleaching in the Caribbean region for the 2010 bleaching season.
In 2005, the active hurricane season greatly reduced the coral bleaching
thermal stress in the Florida Keys and Gulf of Mexico. However, the lack of
tropical cyclones around the Lesser Antilles did not allow storms to
relieve much the thermal stress in the epicenter of the 2005 mass bleaching
event.