9781888569605-ch16

Benthic Habitats and the Effects of Fishing

Ground-Truthing Benthic Habitat Characteristics Using Video Mosaic Images

George R. Cutter, Jr., Yuri Rzhanov, Larry A. Mayer, and Raymond E. Grizzle

doi: https://doi.org/10.47886/9781888569605.ch16

Abstract. Subtidal benthic habitats from the Piscataqua River, New Hampshire and Maine, have been delineated by an automated segmentation technique using bathymetry derived from multibeam echo sounder data. The map, produced by segmentation of seafloor textures, represents a hypothetical benthic habitat map that requires ground-truthing. Video mosaics are being used to ground-truth substrate composition and transitions apparent in the bathymetry data map and to describe biological features and organism occurrences and densities. Here, we describe the utility of video mosaics for ground-truthing benthic habitat characteristics and present two examples of their use. Video mosaics acquired along two transects in the Piscataqua River were used to detect substrate transitions apparent in the bathymetry that were identified as distinct hypothetical habitat types and to quantitatively assess coverages of distinct sediment conditions, density of megafaunal organisms (lobsters), and bioturbational features (crab feeding pits).