Hydroclimatic and anthropogenic fingerprints drive the game between surface-water and sediment microplastics

Microplastics are pervasive in inland waters, yet large-scale association patterns of abundance and traits remain unclear. Here we compiled a global lake database integrating surface-water and sediment observations with 56 hydroclimatic and anthropogenic indicators. Most hydroclimatic variables show positive associations with abundance in surface waters but act oppositely in sediments. Leading contribution patterns differ: leaf area index and 2-m dew-point temperature rank highest in surface waters, whereas solar radiation and wind speed lead in sediments. To enable finer-scale evaluation, we conducted dense sampling in China, which hosts one of the world’s largest and most intensively studied lake systems. Hydroclimatic and anthropogenic fingerprints show clear cross-compartment contrasts: surface-water traits associate strongly with aquaculture production and rural income, while sediment traits more link to population aged 0–14 and chemical oxygen demand. Our findings imply a hydroclimate–human game across compartments, highlighting fingerprints structuring microplastic abundance and traits. Dominant hydroclimatic and anthropogenic factors and their association with microplastic abundance and traits differ markedly between surface waters and sediments, based on a meta-analysis of 56 hydroclimatic and anthropogenic indicators.