The proposed studies would investigate various aspects of the sources, transformations, and fates of dissolved nutrients and organic matter in the Arctic Ocean. Seawater samples (~1,200 total) would be collected during U.S. Navy submarine cruises in the Arctic Ocean during 1997-1999 for the analysis of nutrients (NH4, NO3, NO2. PO4, SiO4) and total organic carbon (TOC), nitrogen (TON) and phosphorous (TOP). The concentrations of lignin-derived phenols dissolved in seawater would also be measured to provide an estimate of the contribution of terrestrially-derived organic carbon to TOC in Arctic Basins. The concentrations and distributions of nutrients and organic matter will be evaluated to determine: 1) if the Bering Strait/Chukchi Sea is a significant source of carbon and nutrients to the Arctic basins, 2) whether Arctic rivers are significant sources of organic matter to basin carbon budgets, 3) if organic matter in the Arctic is a sink for atmospheric carbon dioxide, 4) if biological processes within the Arctic Ocean are responsible for elevated concentrations of TOC.