title: Bottom-trawling along submarine canyons impacts deep sedimentary regimes.
abstract: Many studies highlight that fish trawling activities cause seafloor erosion, but the assessment of the remobilization of surface sediments and its relocation is still not well documented. These impacts were examined along the flanks and axes of three headless submarine canyons incised on the Barcelona continental margin, where trawling fleets have been operating for decades. Trawled grounds along canyon flanks presented eroded and highly reworked surface sediments resulting from the passage of heavy trawling gear. Sedimentation rates on the upper canyon axes tripled and quadrupled its natural (i.e. pre-industrialization) values after a substantial increase in total horsepower of the operating trawling fleets between 1960 s and 1970 s. These impacts affected the upper canyon reaches next to fishing grounds, where sediment resuspended by trawling can be transported towards the canyon axes. This study highlights that bottom trawling has the capacity to alter natural sedimentary environments by promoting sediment-starved canyon flanks, and by enhancing sedimentation rates along the contiguous axes, independently of canyons' morphology. Considering the global mechanisation and offshore expansion of bottom trawling fisheries since the mid-20thcentury, these sedimentary alterations may occur in many trawled canyons worldwide, with further ecological impacts on the trophic status of these non-resilient benthic communities.
authors.affiliation: Departament de Física and Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.
authors.forename: Sarah
authors.initials: S
authors.lastname: Paradis
authors.affiliation: Department of Marine Geosciences, Marine Sciences Institute, Consejo Superior de Investigaciones Científicas, Barcelona, 08003, Spain.
authors.forename: Pere
authors.initials: P
authors.lastname: Puig
authors.affiliation: Departament de Física and Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.|School of Natural Sciences, Centre for Marine Ecosystems Research, Edith Cowan University, Joondalup, WA 6027, Australia.|Oceans Institute &School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
authors.forename: Pere
authors.initials: P
authors.lastname: Masqué
authors.affiliation: Departament de Física and Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.
authors.forename: Xènia
authors.initials: X
authors.lastname: Juan-Díaz
authors.affiliation: Centro Austral de Investigaciones Científicas (CADIC-CONICET), Bernardo Houssay 200, V9410CAB Ushuaia, Tierra del Fuego, Argentina.
authors.forename: Jacobo
authors.initials: J
authors.lastname: Martín
authors.affiliation: Department of Marine Geosciences, Marine Sciences Institute, Consejo Superior de Investigaciones Científicas, Barcelona, 08003, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Palanques