Bottom trawling represents the most widespread anthropogenic physical disturbance to seafloor sediments on continental shelves. While trawling-induced changes to benthic ecology have been widely recognized, the impacts on long-term organic carbon storage in marine sediments remains uncertain. Here we combined datasets of sediment and bottom trawling for a heavily trawled region, the North Sea, to explore their potential mutual dependency. A pattern emerges when comparing the surface sediment organic carbon-to-mud ratio with the trawling intensity represented by the multi-year averaged swept area ratio. The organic carbon-to-mud ratio exhibits a systematic response to trawling where the swept area ratio is larger than 1 yr⁻¹. Three-dimensional physical–biogeochemical simulation results suggest that the observed pattern is attributed to the correlated dynamics of mud and organic carbon during transport and redeposition in response to trawling. Both gain and loss of sedimentary organic carbon may occur in weakly trawled areas, whereas a net reduction of sedimentary organic carbon is found in intensely trawled grounds. Cessation of trawling allows restoration of sedimentary carbon stock and benthic biomass, but their recovery occurs at different timescales. Our results point out a need for management of intensely trawled grounds to enhance the CO₂ sequestration capacity in shelf seas.

底拖网捕捞是对大陆架海底沉积物最广泛的人为物理干扰。虽然拖网捕鱼引起的底栖生态变化已得到广泛认可，但对海洋沉积物中长期有机碳储存的影响仍不确定。在这里，我们结合了北海重拖网地区的沉积物和底拖网捕捞数据集，以探索它们潜在的相互依赖关系。当将表层沉积物有机碳泥比与多年平均扫荡面积比所代表的拖网捕捞强度进行比较时，会出现一种模式。有机碳泥比对拖网捕捞表现出系统响应，其中扫掠面积比大于 1 yr⁻¹。三维物理-生物地球化学模拟结果表明，观察到的模式归因于泥浆和有机碳在拖网捕捞过程中的运输和再沉积过程中的相关动力学。沉积有机碳的增加和损失都可能发生在弱拖网区域，而沉积有机碳的净减少发生在密集拖网的地面上。停止拖网捕捞可以恢复沉积碳储量和底栖生物量，但它们的恢复发生在不同的时间尺度上。我们的研究结果表明，需要对密集拖网捕捞的水域进行管理，以提高大陆架海的 CO₂ 封存能力。