This study investigates the impact of microplastics (MPs) on the vertical transport dynamics of freshwater snow (FWS), a mixture of algae and natural particles, and the subsequent effects on nutrient cycling. The authors used a plexiglass column equipped with a stereoscopic camera system to track the settling velocities of MPs, FWS flocs, and MP-FWS agglomerates. Key findings include: 1. **Settling Velocities**: High-density MPs settled at least twofold faster than FWS alone, except for MP fibers or low-density plastics. 2. **Heteroaggregation**: The formation of agglomerates with MPs increased the settling velocities of FWS, altering the flux of organic matter from the water surface to the bottom sediment. 3. **Model Deviations**: Stokes' law underestimates the settling velocities of irregularly shaped MPs due to increased drag resistance. 4. **Clay as Ballast**: Clay particles did not significantly affect the settling velocity of FWS, unlike MPs. 5. **Biogeochemical Impacts**: The increased settling velocity of FWS due to MP incorporation could alter nutrient cycling and carbon storage in sediments. The study provides insights into how MPs interact with natural particles, influencing their fate and transport in aquatic environments, and highlights the need for more accurate models to predict these interactions.This study investigates the impact of microplastics (MPs) on the vertical transport dynamics of freshwater snow (FWS), a mixture of algae and natural particles, and the subsequent effects on nutrient cycling. The authors used a plexiglass column equipped with a stereoscopic camera system to track the settling velocities of MPs, FWS flocs, and MP-FWS agglomerates. Key findings include: 1. **Settling Velocities**: High-density MPs settled at least twofold faster than FWS alone, except for MP fibers or low-density plastics. 2. **Heteroaggregation**: The formation of agglomerates with MPs increased the settling velocities of FWS, altering the flux of organic matter from the water surface to the bottom sediment. 3. **Model Deviations**: Stokes' law underestimates the settling velocities of irregularly shaped MPs due to increased drag resistance. 4. **Clay as Ballast**: Clay particles did not significantly affect the settling velocity of FWS, unlike MPs. 5. **Biogeochemical Impacts**: The increased settling velocity of FWS due to MP incorporation could alter nutrient cycling and carbon storage in sediments. The study provides insights into how MPs interact with natural particles, influencing their fate and transport in aquatic environments, and highlights the need for more accurate models to predict these interactions.