Detection of coral bleaching using high spatial resolution satellite images

Recent dramatic bleaching events on coral reefs have enhanced the need for global environmental monitoring. This paper investigates the value of present high spatial resolution satellites to detect coral bleaching using a change detection technique. We compared an IRS LISS-III image taken during the 1998 bleaching event in Belize to images taken before the bleaching event. The sensitivity of the sensors was investigated and a simulation was made to estimate the effect of sub-pixel changes. A manual interpretation of coral bleaching, based on differences between the images, was performed and the outcome was compared to field observations. The spectral characteristics of the pixels corresponding to the field observations and the manually interpreted bleachings were analysed and compared to pixels from unaffected areas. 1 Centre for Image Analysis, Uppsala University, Lagerhyddvagen 17, SE-752 37 Uppsala, Sweden. [email protected] 2 MGG/RSMAS, University of Miami, 4600 Rickenbacker Cswy, Miami, FL 33149