Evaluating the performance of the 'Seabin' - A fixed point mechanical litter removal device for sheltered waters

Mechanical interventions are increasingly suggested as a means of removing plastic litter from aquatic environments; their performance is rarely evaluated, but such information is critical to inform policy interventions such as those required to facilitate UNEA 5.2. The Seabin, a fixed-point device designed to remove floating litter in sheltered waters was examined in an urban tidal marina (Southwest UK). It captured on average 58 litter items/day; chiefly plastic pellets, polystyrene balls and plastic fragments. It also captured one marine organism for every 3.6 items of litter, or 13 organisms/day, half of which were dead upon retrieval. The rate of litter capture was inferior to manual cleaning conducted with nets from pontoons or vessels. Hence, in this location the Seabin was of minimal benefit in terms of marine litter removal and resulted in mortality of marine organisms. The presence of such devices could also precipitate false optimism and reliance on technological solutions, rather than systemic changes in our production, use, and disposal of plastics.