Short sediment cores were obtained by a multicorer (Oktopus Kiel) equipped with acrylic tubes (PMMA) with an inner diameter of 10 cm and a length of 60 cm. Sediment slices of 1 cm thickness were cut upon extrusion and stored frozen until analysis in the home laboratory. The frozen sediment slices were freeze-dried and the resulting weight loss was used to calculate the liquid water content (LWC). A subsample of the homogenized dry residues was used to determine the concentrations of total nitrogen (TN), total carbon (TC) and organic carbon (TOC, after removal of inorganic carbon by adding 1 M HCl suprapur to pre-weighed samples in silver capsules) with an Elemental Analyzer (Carlo Erba NA 1500) calibrated against acetanilide. Total inorganic carbon was calculated by difference between TC and TOC.