Assessment of the coral bleaching during 2005 to decipher the thermal stress in the coral environs of the Andaman Islands using remote sensing

Abstract

Sea Surface Temperature (SST) derived from the NOAA AVHRR satellite data were used to generate the Degree of Heating Weeks (DHW) and Hot Spot (HS) products. Combination of the cumulative temperature anomalies and the thermal stress studies were yielded to synoptically identify the probable areas of bleaching. The bleaching status of the Andaman region was assessed based on the DHW and HS for the bleaching event occurred in the Andaman region in April/May 2005. The bleaching status up to Alert Level-1 was recorded with the maximum HS of 3°C and DHW 6°C-week. Simultaneous in-situ reef observations conducted in the Andaman Sea confirmed the coral bleaching event. The maximum mortality in the region due to coral bleaching was shown by the Acropora species (43%) followed by Montipora species (22%) and Porites species (14%). This study focused on detection of coral bleaching warning based on the SST in compliment with the in-situ observations.