Surface sediment grain-size dataset of the Bohai, Yellow, and East China seas based on unified laser diffraction analysis (2001–2019)

Samples were obtained during multiple cruises between 2001 and 2019 using box samplers in accordance with the national standard GB/T 12763.8–2007. All analyses were performed at the Qingdao Institute of Marine Geology, China Geological Survey, using a Malvern Mastersizer 2000 laser particle size analyzer following hydrogen peroxide pretreatment for organic matter removal.The dataset contains the full grain-size distribution at 0.25 Φ intervals (47 bins from −0.75 Φ to >10 Φ), derived Folk–Ward statistical parameters (mean grain size Mz, sorting coefficient σi, skewness Ski, kurtosis Kg), textural fractions (sand, silt, clay), and percentile diameters (D₅–D₉₅).

Sample metadata include unique identifiers, WGS84 geographic coordinates, and sampling year. The consistent analytical protocol — single instrument, single laboratory, unified pretreatment — ensures internal comparability across the entire study region.This dataset supports research on sediment dynamics, paleoenvironmental reconstruction, benthic habitat mapping, and marine spatial planning across the East Asian continental margin.