9781888569605-ch108

Benthic Habitats and the Effects of Fishing

Symposium Abstract: Survey of Fishing Gear and Fiber Optics Cable Impacts to Benthic Habitats in the Olympic Coast National Marine Sanctuary

M. S. Brancato and C. E. Bowlby

doi: https://doi.org/10.47886/9781888569605.ch108

In September 2000 the Olympic Coast National Marine Sanctuary (Sanctuary) initiated a long-term monitoring program designed to assess impacts to the seafloor and the benthic communities from different intensities of commercial bottom trawling and the placement of two fiber optics cables on the seafloor in the Sanctuary. Survey sites were selected based on side scan and bathymetry data and bottom trawling records from Washington Department of Fish and Wildlife, Oregon Department of Fish and Wildlife, National Marine Fisheries Service and vessel traffic tracking information collected by the Sanctuary. We conducted our first two years of monitoring using the Delta submersible equipped with underwater cameras, box core and a benthic suction device (slurp gun). In addition, a shipboard bottom grab was used to collect bottom samples. Four distinct habitat types were monitored along low and high intensities of bottom trawling both along the buried cable route and parallel to the route. The underwater surveys were conducted at depths of 120 to 330 meters along silt/clay, sand, gravel/cobble or boulder with mixed sediments. Physical, chemical, and biological parameters were monitored.