Background: Plastic pollution is of growing concern in marine ecosystems worldwide. Specifically, microplastics (<5 mm) may interact with a variety of biota with the potential to cause harm to organism health. Studies investigating microplastics are increasing, yet their occurrence within free-ranging and living marine mammals remains largely unexplored.
Methods: By using a protocol involving enzymatic digestion, filtration and microscopic identification, faecal samples collected from a grey seal (Halichoerus grypus) haul-out site in the North Sea were investigated for microplastic presence.
Results: Altogether, 71 suspected microplastic particles, consisting of both fibres and fragments in a variety of colours and sizes, were identified across 66 analysed faecal subsamples.
Conclusion: The present study indicates that marine mammals are ingesting microplastics and that faecal material can be used to indirectly and non-invasively record microplastic uptake data in pinnipeds. Since the current paper is the first to document potential microplastic exposure among wild, living and free-ranging grey seals of the western North Sea, further research is needed to begin to understand the biological significance of these findings.
Keywords: anthropogenic change; grey seal; marine mammal; microplastics; trophic transfer.
© 2022 The Authors. Veterinary Record published by John Wiley & Sons Ltd on behalf of British Veterinary Association.