Microplastics in freshwaters: Comparing effects of particle properties and an invertebrate consumer on microbial communities and ecosystem functions.

The effects of microplastic (MP) accumulation in freshwaters on organisms and ecosystem functions are poorly understood, as are the roles of MP particle properties in regulating these effects. In freshwater microcosms, we quantified variation in microbial communities and ecosystem functions and compared effects of MP concentration (0, 1000, 50000 particles/kg), shape (sphere, fragment, fibre), and polymer (polyethylene, polyethylene terephthalate, polypropylene, polystyrene) with those of a model invertebrate consumer (Chironomus riparius). We detected multiple effects of specific MP properties, especially associated with MP fragments and fibres, and the polymer polypropylene.