LIPID DISTRIBUTION IN SURFACE SEDIMENTS FROM THE EASTERN CENTRAL ARCTIC-OCEAN

During the ARCTIC '91 expedition with RV Polarstern, numerous short (m ulticorer) and long cores (kastenlot cores), including surface sedimen ts, were recovered along a transect crossing the eastern part of the A rctic Ocean. In this paper we present data on the concentration and di stribution of short- (C-17, C-19) and long-chain (C-27, C-29, C-31) n- alkanes as well as fatty acids (16:0, 16:1, 18:0, 18:1) in the surface sediments from this transect. These compounds, among others, have bee n used to distinguish between autochthonous marine organic matter and allochthonous terrigenous organic matter supply. Changes in short-chai n n-alkane as well as fatty acid contents of the sediments allow us to distinguish between regions characterized by higher or lower marine p roductivity. Organic carbon contents of the surface sediments are gene rally high and vary between 0.3% and 2%. In general, the high organic carbon content of the sediments is derived from a high input of terrig enous organic matter. Marine productivity in the Arctic Ocean is mainl y controlled by reduced sea-ice cover which allows a higher production rate of phytoplankton. Regions with a higher marine organic matter co ntent are the area NW of Svalbard, the Yermak Plateau, a part of the L omonosov Ridge and Makarov Basin, and the Morris Yesup Rise. The patte rn of distribution of long-chain n-alkanes in Arctic Ocean surface sed iments is mainly controlled by sea-ice and/or direct transport from th e adjacent shelf areas, although dilution by turbidites influences the deep basins. (C) 1997 Elsevier Science B.V.