Porewater was taken from 30 to 50 cm depths in saltmarsh, seagrass and unvegetated areas around the German Bight in 2022 and 2023. Up to 9 points per ecosystem were sampled along a transect. Polysaccharides >5kDa were upconcentrated using AMICON-filtration devide and afterwards freeze dried. Dired samples were resuspended in MilliQ-water and acid hydrolysed (1 M HCl, 24 h, 100°C). Monosaccharides were analysed using anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD, ThermoFisher Dionex ICS-5000+ system equipped with a CarboPac PA10 analytical column (2 x 250 mm) and a CarboPac PA10 guard column (2 x 50 mm)), according to Engel et al. (2011).