Fig. 1
From: Large scale hydrogeochemical and isotopic observations in the Baltic Sea system
Schematic of site and sample types. Beach transect sites included beach groundwater 0.5 m below the sediment surface (dark red X’s) and nearshore surface water (dark red circles) up to 500 m from the shoreline sampled in 2024. Cruise shore-perpendicular transects aligned with beach transects (red circles) were sampled 1–20 km from the shoreline in 2023. For cruise transects, deep water (red crosses) was sampled at the transect endpoints. Conductivity, temperature, depth (CTD) sites included deep water vertical column samples (white crosses) and surface water samples (white circles). Additional sample types include longitudinal sites (white circles, surface water only sites during the cruise) collected between the CTD sites and river surface water (land sampling campaign, see Fig. 2B).
