Acoustic seabed classification of marine physical and biological landscapes
The natural world is structured hierarchically, and processes within natural regions operate across a number of spatial and temporal scales (Turner et al., 2001). Managing marine ecosystems requires that natural regions be identified and mapped over a range of hierarchically nested scales, and management of resources across multiple spatial scales requires a classification system. The development of classification schemes is an active area of marine research. The EUNIS (European Nature Information System) classification scheme is being developed and managed by the European Topic Centre of Nature Protection and Biodiversity (ETC/NPB in Paris) for the European Environment Agency (EEA) and the European Environmental Information Observation Network (EIONET; Davies and Moss, 1999). Alternatively, top–down habitat classification schemes have been developed for global applications in the management of marine resources (e.g. Greene et al., 1999; Valentine et al., 2005). The further development and application of these classification schemes require explicit information that characterizes marine habitats on a variety of spatial scales. Acoustics is increasingly regarded as the remote-sensing tool that will provide the basis for classifying and mapping ocean resources. Existing acoustic systems can measure seabed sediment properties and bedform morphology from scales of centimetres to kilometres.