Title : Accumulation and toxicity of polystyrene microplastics in crabs under waterborne and dietary exposure conditions
Microplastics (MPs) contamination threatens to marine environment. In the present study, the toxicity and trophic transfer potential of MPs from mussel Mytilus coruscus to crab Charybdis japonica were investigated. Waterborne exposure (MPs in water plus clean mussel tissues) and dietary exposure (MPs pre-contaminated mussel tissues as food for crabs) of MPs were conducted to test the bioconcentration and toxic effects of MPs in crabs. Surprisingly, in both tested exposure scenarios, MPs accumulation in tissues primarily occurred in the hepatopancreas and gut, followed by the gills and muscle in crabs. No significant difference was observed between these two exposure routes, obvious biomagnification (BMF) and trophic transfer from mussel to crab through dietary exposure was negative. Dietary uptake was confirmed to be a potential pathway for transport of MPs to higher trophic levels. Also, this study highlights the importance of evaluating potential ecological risks of MPs and trophic cascade effects by in situ experiments and long-term monitoring.