This investigation was carried out in order to evaluate diagenetic element fluxes and different fresh water sources, including submarine groundwater discharge, on the water column of the Wismar Bay (Germany), southern Baltic Sea. Surface and bottom water samples were collected on board of the RV Littorina (L19-06) and a rubber boat by using a submersible pump in May 2019. The water was pumped through a filter cartridge (1 µM pore size) into barrels. Water samples from the barrels were pumped through manganese-coated acrylic fibers to extract radium (Ra) isotopes (223Ra, 224Ra). The Ra isotopes were measured within 3 and 10 days using radium-delayed coincidence counters (RaDeCC). Subsamples were taken via syringe and filtered (0.45 µM, cellulose acetate disposable filters) for analysis of dissolved concentrations of major and trace elements and selected nutrients using ICP-OES (iCAP, 7400, Duo Thermo Fischer Scientific), dissolved inorganic carbon (DIC) and δ13CDIC using isotope gas mass spectrometry (MAT 253 coupled to a Gasbench II), and δ18OH2O, δ2HH2O using a CRDS system (laser cavity-ring-down-spectroscopy, PICARRO L2140- I).