Video transects are systematically sampled by identifying the benthos occurring at fixed points along the transect to the highest taxonomic level possible. The AVTAS software is used to analyse the video transects. During analysis the data are saved into a Microsoft Access¼ database. In order to eliminate confounding in data analyses due to observer biases, transects from each site are analysed by two observers. The observer who actually surveyed the reef in the field analyses transect one from site one and then every alternate transect. A second observer analyses the remaining transects.