Organic carbon in water, particulate matter, and upper layer of bottom sediments of the central part of the Kara Sea

Based on data obtained in the course of the 59th cruise of RV Akademik Mstislav Keldysh, the content of organic carbon was determined in water (dissolved organic carbon, DOC), particulate matter (particulate organic carbon, POC), and bottom sediments of the Yenisei estuary and of the central part of the Kara Sea during the summer-autumn season of 2011. The decisive impact of the waters of riverine runoff upon the variability of DOC and POC concentrations in the marine aquatic area is shown. POC enrichment in the autochthonous component is revealed for the frontal zones, as well as the increase of DOC concentrations in the area of the northern extremity of the Novaya Zemlya Islands. The distribution map of organic carbon (C-org) in the upper layer of bottom sediments of the central part of the Kara Sea is plotted on the basis of the analysis of the authors' and published data. A pronounced enrichment of the thin upper layer (0-0.5 cm) of bottom sediments in organic carbon (> 20%) is registered at most of the stations and depends neither on lithological composition of sediments nor on the location of sampling sites.