From prey to predator: an in-situ observation of microplastic trophic transfer from Mytilus edulis to Asterias rubens

Microplastics are pervasive in marine environments, posing potential risks to aquatic life and human health. This study investigates the trophic transfer of microplastics in marine invertebrates, focusing on the predator Asterias rubens and the filter-feeder Mytilus edulis. Conducted at the White Sea Biological Station, the experiment used polyethylene microspheres (40-48 μm) to trace microplastic ingestion and translocation within these species. Findings demonstrated that microplastics were not only ingested from water but were also transferred through predation from mussels to starfish, providing evidence of trophic transfer among some invertebrate species. Microplastics were detected in both control and experimental groups; however, ingestion rates were markedly higher in experimental conditions. The study introduces a trophic transfer coefficient of 0.36 from mussels to starfish, highlighting the need for further studies to refine microplastic analysis methods in marine settings and explore the ecological impacts on marine species.