“…Moreover, as underlined by several authors (eg, Kvernevik et al, 2002), most of the methods used to map seafl oors are expensive with respect to both time and money. Consequently, few long-term monitoring methods exist in the marine environment beyond those pertaining to 'structured habitats' such as coral reefs or mangroves in tropical areas (Green et al, 1996;Chauvaud et al, 1998;Holden and Le Drew, 1998;Manson et al, 2003;Philipson and Lindell, 2003;Proisy et al, 2007) and seagrass beds in temperate or tropical areas (Larkum et al, 2006;Orth et al, 2006;Wabnitz et al, 2008), for which the long-term spatiotemporal dynamics can be monitored by remote sensing methods (eg, Godet et al, 2008). The study of spatiotemporal dynamics of such habitats is very useful as potential ecological indicators, but, by defi nition, global changes affect all marine benthic species and habitats, including common and widespread species and habitats (Edwards and Richardson, 2004).…”