Microplastic in angling baits as a cryptic source of contamination in European freshwaters

Abstract High environmental microplastic pollution, and its largely unquantified impacts on organisms, are driving studies to assess their potential entry pathways into freshwaters. Recreational angling, where many anglers release manufactured baits freshwater ecosystems, is a widespread activity with important socio-economic implications in Europe. It also represents pathway freshwaters that has yet be quantified. Correspondingly, we analysed three different categories of industrially-produced (‘groundbait’, ‘boilies’ ‘pellets’) for contamination (particles 700 µm 5 mm). From 160 samples, 28 microplastics were identified groundbait boilies, mean concentration 17.4 (± 48.1 SD) MP kg −1 6.78 29.8 mg , no within this size range recorded the pellets. Microplastic concentrations significantly differed between bait companies, but characteristics did not vary. There was correlation number ingredients, it positively correlated C:N ratio, indicating higher proportion plant-based ingredients. We thus reveal introduced accidentally during manufacturing and/or those originating from contaminated raw ingredients might transferred However, further needed quantify relative importance cryptic source how influences levels wild fish.