Diagenesis and Exchange Processes at the Benthic Boundary

Benthic decomposition determines the portion of detrital organic matter that is utilized by organisms for their biomass production and energy requirements, the remainder being buried in the sediment column. Benthic decomposition on the other hand also determines to a large extent the nutrient release to the overlying water column which — in the case of shallow sea areas — may be large enough to satisfy up to 100 % of the nutrient requirements for pelagic primary producers (ZEITZSCHEL and DAVIES 1978, ZEITZSCHEL 1980). For an evaluation of the role of the bottom sediment in the cycling of organic matter constituents, an area of investigation such as Kiel Bight appears particularly suited since (i) a decade of interdisciplinary research has yielded results to tackle most of the problems currently under discussion in this field, (ii) data from long-term studies stretching back more than 20 years may be recalled to rate short-term findings and (iii) Kiel Bight comprises widely different sedimentary regimes ranging from newly eroded sands to rapidly accumulating, organic-rich mud sediments.