Seepage rates and hydrochemistry

Coastal peatlands are important carbon, nutrient, and trace metal stores, which might be mobilized and released to the adjacent sea upon rewetting. The objectives of this study were to quantify submarine groundwater discharge (SGD) in front of a rewetted coastal peatland at the southern Baltic Sea coast, to estimate associated fluxes of solutes, and to characterize the discharged water using stable oxygen, hydrogen, and carbon isotope composition. We directly measured SGD rates and collected the discharging water using seepage meters in summer and autumn 2021. SGD, seawater and groundwater were analyzed for major ion, nutrient, DOC/DIC and trace metal concentrations as well as the composition of water and carbon isotopes. Racasa et al. (2026) is based on this dataset.