SEA SURFACE TEMPERATURE INFLUENCED CORAL BLEACHING IN THE SALTWATER ISLANDOF GULF OF MANNAR, EASTERN SEA BOARD OF INDIA

The Corals are symbiotic organisms which are very sensitive to different environmental variables and can tolerate up to their optimal limits. However SST is a key factor in terms of coral bleaching which can result in the mortality of the corals thereby retarding their growth in coral environments. Based on the available cloud free satellite data, the health of the corals during 2000-2009 was assessed in coral environs of the Gulf of Mannar (GoM). Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper plus (ETM+) data were used for identification and mapping of coral reefs, and National Oceanic and Atmospheric Administration (NOAA) Advance Very High Resolution Radiometer (AVHRR) derived SST data was used to assess the thermal stress and its induced bleaching. This study is concerned about the bleaching of coral reefs in response to SST. The average of monthly AVHRR SST data of ~5km radius on saltwater island out of 21 islands was taken in order to find out the time series data for saltwater island which was considered as virtual station of respective islands. Then variation of Sea Surface Temperature (SST) data was correlated with health of coral environment. The results suggested that during 2002 and 2005 coral reef bleaching might have been induced due to elevated SST.