Negative impacts of realistic doses of spherical and irregular microplastics emerged late during a 42 weeks-long exposure experiment with blue mussels

摘要: Abstract Microplastics have been found in all compartments of the environment, and numerous life forms are known to take up anthropogenic particles. Marine filter feeders particularly susceptible ingest suspended microplastics, but long-term studies on potential effects this uptake scarce. We exposed juvenile Mytilus spp. environmentally realistic doses irregularly shaped polyvinylchloride (PVC) particles (15, 1500, 15,000, 150,000, 1,500,000 particles/individual/week calibrated size range 11–60 μm) regularly polystyrene (PS) beads 15,000 particles/individual/week, 40 μm) over 42 weeks. During period, we monitored physiological traits such as clearance rate, byssus production, growth superoxide dismutase (SOD) activity, malondialdehyde (MDA) concentrations, condition index (CI). Negative tested microplastics mussel performance emerged late experiment were rather weak. Interestingly, even after having received lowest particle dose PS, SOD activity gill was significantly lower mussels compared a group conspecifics that kept clean water. However, CI, which both closely related fitness mussels, not be impaired at end exposure phase. This is so far longest laboratory microplastic study worked with reflect todays pollution levels. The small effect sizes observed for response variables assessed suggest these specific pose only minor threat blue populations.