Seabed biotope mapping using multi-beam backscatter based on reference sites

A multibeam sonar (MBS) was used to discriminate ecological relevant seabed characteristics based on 62 reference sites spanning depths 50 m to 400 m sampled with georeferenced video, sediment grab and rock dredge. The simple ecologically derived terrain characteristics of soft, hard, smooth and rough were found to have the most predictive power for discrimination of the biota using data from video and physical sampling. The acoustic data were corrected for range and incidence angle effects and analysed based on phenomenological characteristics and inversion of a seabed scattering model. Near normal incidence (