Seafloor litter samples were collected as part of the International Bottom Trawl Surveys in 2021 and 2022. The surfaces of 146 macrolitter items taken from benthic trawl surveys conducted in the North-East Atlantic were examined for the presence of macrofauna, including Non-Indigenous Species (NIS). A total of 145 taxa were recorded, including three NIS (the barnacles Solidobalanus fallax and Austrominius modestus and the slipper limpet Crepidula fornicata).

The three NIS were found exclusively in the English Channel, on litter items likely to have been recently reclaimed from very shallow coastal waters. No NIS were found in the Bay of Biscay, however a large amount of litter from longline fisheries was found to be colonised by diverse sessile communities. Dominant litter plastic types were smooth flexible polyethylene and polyamide – found mostly in the form of monofilament fishing lines.

The results from this study will be pooled with those from a sister study led by Cefas, thus bringing together into a single dataset 251 colonised seafloor litter items. The resulting broad-scale dataset will allow us to compare litter items and plastic types with fouling communities.