Quantification of the flux of organic matter reaching the seafloor of the ocean or coastal regions is an important objective with respect to microbial turn-over processes, remineralisation of nutrients, pH of the sediment as well as formation and fate of H2S or methane. Measurement of pore water profiles allows calculation of fluxes of dissolved constituents as well as estimates about the rain rate of particulate matter.
Measurements of oxygen profiles from the bottom water into the surface sediment allows to quantify the rain rat of particulate organic matter (POM) reaching the seafloor.
Since the gradients of O2, pH and other dissolved constituents across the sediment-water-interface (SWI) are rather steep and might be affected by sediment sampling and pressure release, in situ measurements by microelectrodes (Revsbech, Reimers, Gundersen) are required for several settings.
For this purpose we apply an in situ microprofiler. This system consists of a motor housing which allows a vertical positioning of <0.1mm, the data acquisition unit and microelectrodes.  The system is installed in s Lander System or deployed by an ROV. In the later case syntactic foam, providing buoyancy is attached to the in situ system.