Data on concentration of total carbonate together with calcium, total alkalinity, salinity, and temperature from the Canadian Expedition to Study the Alpha Ridge (CESAR) Ice Camp, the Ymer 80 expedition and the 1984 F. S. Polarstern Marginal Ice Zone Experiment (MIZEX 84) are used to assess the transport the CO2 into the different water masses of the Arctic Ocean. Most of this CO2 goes into the surface mixed layer and halocline waters. A small flux to the Atlantic layer is discernible. No flux to the deep water could be observed. It is possible to separte the carbon input to the Arctic Ocean into three components: carbon from the atmosphere fixed in river drainage basins (40¿20¿1012 g C a-1), carbon from dissolved mineral calcium carbonate in river drainage basins (40¿20¿1012 g C a-1), and carbon from the atmosphere fixed over the continental shelves (129¿65¿1012 g C a-1). From these we estimate the transport of decayed organic carbon from the tundra to the Arctic Ocean and the ''new production'' of 45¿20 g C m-2 a-1 for biogenic carbon over the continental shelves of the Arctic Ocean. ¿ American Geophysical Union 1990