Correlation of Coral Bleaching Events and Remotely-Sensed Sea Surface Temperatures
Abstract
In the 1980s and early 1990s, coral reef bleaching events of unprecedented frequency and global extent were observed. Elevated water temperature is suspected as the primary causal stress of mass bleaching events from this period. The relationship between sea surface temperatures (SSTs) and coral bleaching events was investigated using National Oceanic and Atmospheric Administration (NOAA) Multi-Channel Sea Surface Temperature (MCSST) satellite imagery from 1982-1992. Nighttime MCSST weekly averages were compared with moored-buoy temperatures for sea-truthing the satellite. Average errors from 11 individual buoy comparisons throughout the tropics were found to be approximately 0.5 deg C when satellite data contaminated by volcanic aerosols (El Chichon 1982/83, Mt. Pinatubo 1991/92) were discarded. Confirmed satellite SST data were applied to bleaching events at Bermuda (1988, 1991), Tahiti (1984, 1987, 1991), and Jamaica (1987, 1989, 1990), with a non-bleached site off Belize selected as control. MCSST data showed elevated SSTs coincided with bleaching events both in onset and duration. A satellite temperature bleaching 'threshold' was produced for the three sites, and histogram analyses of MCSST temperatures revealed increased periods of high SSTs correlated with the occurrence of mass bleaching events. An MCSST Degree Heating Weeks (DHW) bleaching index was developed for the Belizean and Jamaican reef sites. A cumulative heating stress of 26 DHW is proposed as the threshold for mass reef bleaching at Belize and Jamaica. Corals, Coral bleaching, Remote sensing, Sea Surface Temperatures (SSTS)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 19, 1994
- Accession Number
- ADA284907
Entities
People
- Michael W. Gleeson
Organizations
- United States Naval Academy