A paired marine-fluvial modern pollen dataset from the Bohai Sea and its inflowing rivers, China

Modern marine pollen records can be interpreted reliably only when the main source-to-sink processes between terrestrial vegetation, rivers, and marine depocentres are documented by comparable modern data. Here, we present and quality-assess a paired marine-fluvial pollen dataset for the Bohai Sea, China, consisting of 430 marine surface-sediment samples and 104 fluvial surface-sediment samples from 16 major inflowing rivers. The dataset includes sample coordinates, water depth for marine stations, river and regional identifiers, pollen and spore counts and percentages, pollen concentrations, and grain-size parameters. In total, 104 pollen and spore morphotypes were identified. Marine assemblages are dominated by arboreal pollen, especially Pinus (mean 59 %), whereas nearshore and river-influenced settings contain higher proportions of herbaceous taxa, particularly Chenopodiaceae/Amaranthaceae-type (mean 14 %), Artemisia , and Poaceae. Redundancy analysis after variance-inflation-factor screening indicates that water depth is the strongest retained predictor of marine pollen composition (λ1/λ2=0.303), followed by geographic position and sediment texture. In river samples, geographic position, water discharge, and pollen concentration together explain 20.53 % of the compositional variance. Along the 0–35 m depth interval, arboreal pollen and Pinus percentages increase with water depth, whereas herbaceous percentages decrease, providing an internally consistent modern analogue for distinguishing nearshore fluvial influence from more distal marine influence, where buoyant saccate pollen is enriched by a combination of atmospheric transport and hydrodynamic sorting. The dataset is intended primarily as a reusable calibration and quality-assessment resource for palaeoenvironmental studies in the Bohai-Yellow Sea region. The archived data are available at the National Tibetan Plateau Data Center (TPDC; https://doi.org/10.11888/Paleoenv.tpdc.303516, Li and Yang, 2026).