A Multi-Tracer Study of Fresh Water Sources for a Temperate Urbanized Coastal Bay (Southern Baltic Sea)

Terrestrial surface waters and submarine ground water discharge (SGD) act as a source of dissolved substances for coastal systems. Solute fluxes SGD depend on the composition water-solid-microbe interactions close to sediment-water interface. Thus, this study aims characterize evaluate hydrogeochemical gradients developing in fresh-salt mixing zone Wismar Bay (WB), southern Baltic Sea, Germany. Sampling campaigns covering WB, at beach WB shoreline, terrestrial near well sediments pore were carried out. In these different waters, distribution inorganic carbon, nutrients, major ions, trace elements, stable isotopes (H, O, C, S), radium have been investigated. Enhanced concentrations together with manganese, barium eastern indicated benthic-pelagic coupling via exchange between column. Salinity, isotopes, ions sediment profiles identified presence fresh below about 40 cmbsf central part bay. Geophysical acoustic techniques revealed local impact anthropogenic excavation, which reduced thickness layer aquifer bottom water, causing, therefore, upward flow top sediments. The impacted isotope (δ 18 δ 2 H) plot regional meteoric line indicating relatively modern source. calculated organic matter mineralization rates carbon much higher site when compared other unimpacted Therefore, reveals that sources contribute balance including