A Seabin is a floating bin fixed in a marina or harbour. A pump pulls water in through a catch bag and returns it, leaving floating litter behind.
Researchers at the University of Plymouth ran the first independent test of one, in a Plymouth marina between April and June 2021. Measured: in 750 hours it caught 1,828 pieces of litter weighing 0.18 kg in total, about 58 pieces a day. Most were plastic pellets, polystyrene balls and plastic fragments.
It also caught one animal for every 3.6 pieces of litter, about 13 animals a day, including sandeels, brown shrimp and crabs. Around 60% of them were dead when the bag was emptied.
For comparison, people with hand nets collected an average of 19.3 g of litter in cleans of up to five minutes. In the same time, the Seabin caught the equivalent of 0.0059 g. The researchers concluded that in this marina the device was of minimal benefit, and that manual cleaning was more efficient and cheaper. They also warned that devices like this can distract from changing how plastic is made, used and thrown away.
Why it matters: clean-up devices get a lot of attention, but they catch very little compared with what never gets into the water in the first place. Using less plastic, and stopping litter at its source, does far more.
The study was funded by the European Union's INTERREG France (Channel) England programme, through its Preventing Plastic Pollution project. Seabins are made and sold by Seabin Pty Ltd, a for-profit company in Australia. The Seabin Foundation, a separate Australian charity, placed some devices and ran volunteer programmes.