Applying Discriminate Analysis to Characterise Shallow Rocky Reef Habitat

A major goal of seafloor habitat mapping is to provide techniques that predict the distribution of species from physical and biotic parameters that define where species live. An area of seafloor comprising of rocky reef and sand habitats was surveyed with both a single beam acoustic ground discrimination system (AGDS) and sidescan sonar. Comparisons are made between predicted classes assessed from AGDS measurements and the digitised layer of the sidescan mosaic. The application of discriminate analysis to create a classification rule for the rocky reef areas revealed that 83% of the classification could be predicted by depth and hardness. These results can be used to improve classification of single beam acoustic data in the near-shore depth zone in the range 15-25 meters.