Sources and Pathways of Organic Carbon in the Modern Laptev Sea (Arctic Ocean): Implication from Biological, Geochemical and Geological Data

Abstract

Summary: During the past six years organic geochemical, micropaleonto­ logical, and sedimentological investigations were carried out within the framework of the multidisciplinary bilateral research project System Laptev and detailed biological investigations within the project German-Russian Investigations of the Marginal Seas of the Eurasian Arctic, In order to understand the Laptev Sea ecosystem and to obtain information about sources and fate of organic carbon, the distribution of phyto- and zooplankton, diatoms, chlorophyll a benthic macrofauna, palynomorphs, grain size, total organic carbon, Cl 13Corg and biomarkers (n-alkanes, fatty acids) were determined. In general, the influence of the major rivers draining into the Laptev Sea, is reflected in the water column as weil as in the surface sediments. In both habitats three ecological provinces can be distinguished, i.e., the southeastern Laptev Sea, the central Laptev Sea, and the northern Laptev Sea. Additionally, clear differences between the western and the eastern Laptev Sea occur. The comparison of the different data sets of the water column and the surface sediments provide information about organic carbon sources and pathways in the Laptev Sea shelf and continental slope area.