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Seagrasses are important for coastal processes because of their role as ecosystem engineers (Jones et al. 1994), and because they provide nursery habitat for numerous juvenile fish and invertebrates, feeding grounds for dugongs and sea turtles and protection against coastal erosion (Orth et al. 1984, Bell and Pollard 1989, Costanza et al. 1997, Nagelkerken et al. 2000). However, natural and anthropogenic disturbances have led to a worldwide decline of seagrasses (Green and Short 2003). Knowledge of seagrass biomass is very useful for managing and evaluating these ecosystems, since it responds quickly to environmental alterations and its changes are, in many cases, big enough to be monitored using remote sensing (Kirkman 1996).Remote sensing, with its large spatial coverage, has been used effectively to create baseline maps and to determine temporal change in the spatial extent of seagrass areas (Ferguson et al. 1993), percentage cover (Gullstrom et al. 2006) and above ground biomass (Mumby et al. 1997). High accuracy remotely sensed maps of seagrasses have been obtained in areas with clear and shallow water and large homogeneous seagrass beds (Robbins 1997, Mumby et al. 1997, Lyons et al. 2013). In contrast to such ideal conditions, many near shore areas in Malaysia are often characterized by small and patchy seagrass areas with a mix of dominant species growing in waters with limited visibility. In this research, improvised algorithms for mapping seagrass and biomass estimation will be studied by using high spatial and spectral resolution satellite data together with sea-truth measurements. The sea-truth measurements will be carried out by using suitable size quadrat sampling. The above ground biomass will be determined using appropriate techniques. |