BioGeoChemistry of Tidal Flats


J. Rullkötter, M. Simon

Interdisciplinary research on hydrodynamics and biogeochemistry in the Spiekeroog tidal basin of the southern North Sea

An interdisciplinary resarch project was established to obtain a fundamental understanding of important physical and biogeochemical processes in a tidal flat system. The backbarrier tidal flat of Spiekeroog island on the East Frisian coast (southern North Sea) was chosen as the study area. A weather-independent time-series station was positioned in the main channel of the tidal inlet near the southern tip of the island. It automatically records meteorological data, physical parameters of the water body as well as its load of suspended matter. Nutrient, heavy metal and methane concentrations in the water column are measured at frequent intervals, and the development of automatic monitoring devices for these parameters is underway. Biogeochemical transformations and material fluxes are determined on water-column-suspended particles, at the sediment-water interface and in the sediments. An important focus is the microbial system in the deeper anoxic layers of the tidal flat sediments. Mathematical modelling addresses the hydrodynamic system and the ecosystem including the biogeochemical processes. The presentation provides an overview of the research approach as well as the most important results after four years of investigation.