Side-Scan Sonar Imaging of Subtidal Benthic Habitats in the Mullica River–Great Bay Estuarine System

Side-scan sonar imaging conducted in Great Bay, New Jersey, during August 2003 reveals local variations in acoustic backscatter from the seabed that can be related to small-, medium-, and large-scale bedforms. Analysis of 600-kilohertz side-scan sonar data collected at a System-Wide Monitoring Program (SWMP) survey site of the Jacques Cousteau National Estuarine Research Reserve shows a relationship between backscatter intensity, bathymetry, and changing seabed morphology. Side-scan sonar records obtained at the survey site in Great Bay via deployment of an autonomous underwater vehicle (Remote Environmental Monitoring UnitS) provide in-depth characterization of an array of complex and multiscaled bedforms and associated benthic habitats. Bedforms documented within the swath map region by side-scan sonar imaging include constructive transverse forms, notably ripples, dunes, and sand waves. These bedforms are valuable for assessing potentially important habitats for benthic invertebrate and demersal finfish populations.