Submarine Groundwater Discharge-Derived Nutrient Fluxes in Eckernförde Bay (Western Baltic Sea)

• DOI: 10.1007/s12237-023-01202-0
• Publication Date: 2023-05-08T15:15:57Z
• Authors: M. Kreuzburg; J. Scholten; Feng-Hsin Hsu; V. Liebetrau; J. Sültenfuß; J. Rapaglia; M. Schlüter
• Keywords: Submarine groundwater discharge

Abstract Excess nutrient supply by the rivers and atmosphere are considered as major causes for persistently poor ecological status of Baltic Sea. More than 97% Sea still suffers from eutrophication due to past present inputs nitrogen phosphorus. One poorly quantified sources in is submarine groundwater discharge (SGD). Through seepage meter deployments a radium mass balance model, widespread occurrence SGD along coastline Eckernförde Bay was detected. Mean 21.6 cm d −1 with calculated freshwater fraction 17%. Where detected, pore water sampled piezometer revealed wide range dissolved inorganic (DIN: 0.05–1.722 µmol L ) phosphate (PO 4 3− : 0.03–70.5 concentrations. DIN PO concentrations non-saline (salinity < 1) waters were 59 ± 68 1.2 1.9 , respectively; whereas salinities > 1 higher values, 113 207 6 12 respectively. The salinity gradient do not suggest that land-derived definitive source nutrients Still, may contribute autochthonous source, resulting remineralization or dissolution processes organic matter sediments. fluxes derived rates through meters 7.9 9.2 mmol m −2 0.5 0.4 lower factor ~ 2 5 when compared model (mean DIN: 19 28 ; mean 1.5 2.7 ). Assuming these radium-based representative Bay, we arrive at SGD-borne about t km y 0.2 phosphorous. These same phosphorus riverine 6.3 P: German identifying secondary