Visual quantification and identification of shallow seafloor marine litter in the southernmost North and Baltic seas using an epibenthic video sledge (EVS) - A comparison to bottom trawl data

The quantification of the marine litter at the seafloor is a challenging process. Currently the majority of the data of marine litter at the seafloor is a by-product of bottom trawl fish stocks assessment. In the search for a new, less invasive and universally usable method, an epibenthic video sledge was used to make video recordings of the seafloor. With these videos a visual estimation of the marine litter in the southernmost North and Baltic seas was done. The estimated mean litter abundances with 526.8 litter items (LI)·km⁻² in the Baltic Sea and 305.1 LI·km⁻² in the North Sea are significantly higher compared to bottom trawl studies. Using both results conversion factors for marine litter catch efficiency of two fishing gears were calculated for the first-time. These new factors now allow obtaining more realistic quantitative data of seafloor litter abundance.