Georeferenced Sediment and Surface Water Element Concentrations in the Coastal Liepāja Lake (Latvia), 2024

Liepāja Lake, a Natura 2000 protected area and one of the largest coastal freshwater bodies in Latvia, has been historically influenced by urbanization, diffuse agricultural inputs, and legacy contamination from metallurgy and ship-repair industries. Comprehensive, spatially explicit data on its sediment and water chemistry were previously lacking. The dataset used in this study provides an openly accessible record of major and trace element concentrations in surface sediments and surface waters collected during the 2024 field campaign. Sampling sites were distributed across northern, central, and southern zones to capture gradients in anthropogenic pressure and natural variability. Water samples were filtered and acidified following ISO 15587-2:2002, while sediments were homogenized, sieved, and digested following EPA 3051a. Both matrices were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS, Agilent 8900 ICP-QQQ) with multi-element calibration traceable to NIST standards. The dataset comprises 31 analytes (Li–Bi) with paired standard deviation values, reported in mg kg –1 (sediments) and µg L –1 (water). Rigorous validation included certified reference materials, duplicates, blanks, and statistical outlier screening. The resulting data form a reliable geochemical baseline for assessing pollution sources, quantifying spatial heterogeneity, and supporting future monitoring, modeling, and restoration efforts in climate-sensitive Baltic coastal lakes.