Investigations focus on the benthic boundary layer (BBL). A zone extending from a couple of hundred metres above the sediment to about 5m into the sediment. Most of the studies concentrated to the nepheloid layer and the bioturbated sediment layer. Vertical and lateral input of carbon into the BBL is determined by physical processes as well as by organisms. The bathy- and abysso-pelagic zooplankton and nekton including its bentho-pelagic components act as mediators between the productive oceanic surface layer and the benthos. The flux rates measured at the sediment/water interface, thus, mediate between short time scales of oceanic surface layer processes and the long time scales of processes in sediment layers beneath the bioturbated and bioirrigated sediment surface. Past productivity and modes of deposition (aeolic-seasonal, fluvial-seasonal up to episodic, turbidical-episodical) are reconstructed from amount and composition of trace elements in the solid phase and porewater.