Dredging at UK ports disturbs seabed carbon: study shows 30-fold increase over 200 years

A new study from the Convex Seascape Survey reveals that dredging at UK ports has disturbed seabed carbon stores, with impact increasing 30-fold since the 1830s. Researchers combined modern data with historical records to track how organic carbon in sediment across the Northwest European shelf has been affected by port maintenance activities. While fishing gets more attention, the study highlights dredging as a persistent but overlooked source of carbon disturbance. The research, led by Ellie Maynard at the University of Exeter, is the first to quantify long-term seabed carbon disturbance from human activities using historical archives. The team found that muddy seabeds are especially carbon-rich and should be prioritized for protection. Policymakers are urged to adopt targeted ocean management that identifies areas most exposed to carbon-disturbing activities. Although the ultimate fate of disturbed carbon remains uncertain, the findings support stronger monitoring and mitigation measures. The study fills a key knowledge gap and could inform future decisions on port maintenance and marine conservation in UK waters.