Jutta Niggemann¹, Beatriz Elizabeth Noriega-Ortega^1,2, Gerrit Wienhausen³, Thorsten Dittmar^1,4 and Meinhard Simon^3,4, (1)University of Oldenburg, Research Group for Marine Geochemistry (ICBM-MPI Bridging Group), Oldenburg, Germany, (2)Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany, (3)University of Oldenburg, Institute for Chemistry and Biology of the Marine Environment (ICBM), Biology of Geological Processes - Aquatic Microbial Ecology, Oldenburg, Germany, (4)Helmholtz Institute for Functional Marine Biodiversity at University of Oldenburg, Oldenburg, Germany