The significance of trophic transfer of microplastics in the accumulation of plastic additives in fish: An experimental study using brominated flame retardants and UV stabilizers

Marine organisms ingest microplastics directly from water and indirectly from food sources. Ingesting microplastics can lead to the accumulation of plastic-derived chemicals. However, the relative contributions of the two exposure routes to the accumulation of plastic-derived chemicals in organisms are unknown. Using microplastics containing two brominated flame retardants (BFRs; BDE209 and DBDPE) and three UV stabilizers (UVSs; UV-234, UV-327, and BP-12), we performed exposure experiments to compare chemical accumulation patterns in fish (Myoxocephalus brandti) between exposure from water and prey (Neomysis spp.). We found significantly higher concentrations of BFRs in fish fed microplastic-contaminated prey than fish exposed to microplastics in the water. However, we observed similar concentrations of UVSs in fish exposed to both sources. As BFRs are more hydrophobic than UVSs, the differences may reflect the hydrophobic nature of the additives. Our findings indicate that both exposure routes are crucial to understanding the accumulation of plastic additives in fish.