Persistence of Biogeochemical Alterations of Deep?Sea Sediments by Bottom Trawling

Bottom trawling grounds have been expanding to deeper areas of the oceans since mid-XXth century, and mitigating strategies aimed protect fish stocks, such as temporal closures, recently implemented. Here we investigated biogeochemical properties sediment from a deep-sea ground in Palamós Canyon (NW Mediterranean) assess effects 2-months closure recovery sedimentary organic matter. In comparison untrawled areas, continuous erosion mixing led coarser reworked sediments impoverished carbon (?30% loss) promoted degradation labile compounds (52–70% loss). These impacts persisted after closure, highlighting that this management strategy is insufficient restore seafloor. Considering expansion bottom grounds, activity could significant irreversible on ocean margins at global scale, hampering their burial capacity.