Organic matter characterization in Barents Sea and eastern Arctic Ocean during summer

The characteristics and distribution of the organic matter (OM) pool were investigated in the northern Barents Sea shelf region and eastern Arctic Ocean in July 2004. The first results on the vertical and horizontal distributions of surface-active substances and folic acid are presented along with dissolved organic carbon (DOC) measurements and sulfur determination, and related to salinity, temperature, and chlorophyll a (Chl a). Neutral and low acidity substances dominated the surface-active OM pool at all depths and stations investigated. Characterization of hydrophobic/hydrophilic properties of the OM revealed the dominance of more hydrophobic substances in the upper mixed layer and highly hydrophilic substances in deep waters. Electrochemically detectable organically bound sulfur was a minor component compared to the presence of inorganic forms of sulfur, S2−, S0, detected in concentrations up to 10 nmol l− 1. DOC concentrations were more or less uniform in the entire region, while SAS concentrations were elevated in the upper mixed layer. The OM pool was larger in the northern Barents Sea, east of Svalbard, than in the eastern Arctic Ocean station, north of Svalbard.