Sediments of the Norwegian-Greenland Sea were analysed for concentration, and enzymatic degradation potential of organic material, and additional environmental parameters related to microbial enzymatic activities. The pool of extracellular enzymes in the sediments has to be characterized as tolerant against variations of temperature and pressure. Instead, the availability of decomposable organic carbon was the main factor regulating enzymatic activities. Concentration and decomposition of organic matter varied strongly dependent upon location. Sediments from the Jan Mayen Fracture Zone colonized by epibenthic foraminifera revealed low organic carbon (C) and nitrogen (N) concentrations, low C/N ratios, and high enzymatic activities as compared to the other sediments investigated (Barents Sea, Kolbeinsey Ridge, East Greenland Shelf, Lofoten Basin, Vøring-Plateau).The occurrence of macrofauna and their biogenic structures greatly enhanced enzymatic activities. The existence of epibenthic foraminifera coincided with steep gradients of enzymatic activities in the uppermost sediment surface layers. The metabolic status of individual foraminifera could be detected by their enzymatic activities. One active foraminifer could already account for the hydrolytic activity measured in one cm4 of surface sediment. In sediments across the continental slope of the Barents Sea, general patterns of the decomposition and preservation of the deposited organic matter strongly dependent on the nutrient supply and the benthic colonization could be demonstrated. Sediments located on the slope with very high sedimentation rates showed a good preservation of the deposited organic material with C/N ratios close to ratios of surface sediments. Sediments located at the base of the slope with a very low supply with organic material revealed a preferential relative enrichment of N over C (low C/N ratios) of the residual organic material. Sediments located on the shelf with intermediate sedimentation rates were characterized by an incomplete oxidation of the deposited organic matter thus leading to the relative enrichment of Cover N (high C/N ratios). These observations demonstrate that the original signature of the sedimented organic material can be overprinted by biological activities. The mode of overprinting (relative enrichment of either C or N) is dependent upon the sedimentation rates of organic matter and the benthic colonization.
Weitere Kapitel dieses Buchs durch Wischen aufrufen
- Concentration and Microbial Decomposition of Organic Material in Sediments of the Norwegian-Greenland Sea
- Springer Berlin Heidelberg
Systemische Notwendigkeit zur Weiterentwicklung von Hybridnetzen