2018 Ocean Sciences Meeting

February 11-16

Bottom trawling is a nonselective commercial fishing practice whereby heavy nets and gear are dragged along the seafloor. The role of trawling activities in present-day sediment dynamics may be under appreciated. The direct and indirect impacts of this fishing technique on continental margins can modify the physical properties of surface sediments and alter sediment fluxes and budgets. Fishing gear produces not only the scraping and ploughing of the seabed or the crushing of biogenic structures and small-scale bottom relief, but also the resuspension of sediment with an associated significant increase in near-bottom turbidity that can propagate away from fishing grounds by ambient currents and/or sediment-gravity flows. The chronic impact of trawling alters surface sediment properties, texture and composition, modifies chemical exchanges across the water-sediment interface, causes changes of erosion/accumulation rates and produces shifts of benthic communities, including “ecosystem engineers”, which in turn influence the physical properties of the surface sediments. The sum of these human-induced perturbations of the seafloor results in measurable alterations of the seabed integrity and submarine geomorphology from micro-reliefs to regional spatial scales. We welcome submissions that address trawling-induced sedimentary processes or any other anthropogenic activity (e.g. dredging, deep-sea mining) causing similar impacts on the seabed.

• F - Fisheries
• ME - Marine Ecosystems
• PO - Physical Oceanography: Other