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Effects of Trawling and Dredging on Seafloor Habitat
FIGURE C.1 Typical configurations of various types of seafloor mapping instruments discussed in this report (U.S. Geological Survey, 2001).
multibeam bathymetry system with backscatter data recorded might be ideal. In an area where individual boulders are important habitats, a sidescan system would probably be a better choice. If the seafloor is of uniform composition, but subtle changes in depth are important, a high-resolution multibeam system is appropriate. An automatic bottom classification system might be used as a preliminary reconnaissance tool to expand from a well-known area into an unknown area. The use of supporting data—from substrate samples or photographic or video observations—is necessary to interpret data from any of these mapping tools in terms of habitat.