Marine litter occurrence and composition were investigated during routine bottom trawl fish surveys type BITS performed in the Polish Maritime Areas (the southern Baltic Sea). Sampling covered a distance of 325 km and an area of 16 km2 at a depth range of 19–110 m. Litter densities varying between 0 items/ha (34% of tows) and 2.23 items/ha with a mean of 0.20 items/ha (SD = 0.30) are at the bottom range of densities reported from other shelf habitats worldwide at similar water depths. The majority of the items (40%) were found at a depth range of 51–60 m. Overall, plastic was the most common litter type (67% of all items) found in all tows with litter. The results of this study indicate that despite the Baltic being a semi-enclosed basin, with a densely populated coastline and extensive shipping, marine litter pollution of the southern Baltic seafloor is low compared to other coastal areas.
Barbara Urban-Malinga, Tycjan Wodzinowski, Bartosz Witalis, Mariusz Zalewski, Krzysztof Radtke, Włodzimierz Grygiel, Marine Pollution Bulletin, Volume 127, February 2018, Pages 612–617