PATTERNS OF NITRATE UTILIZATION AND NEW PRODUCTION OVER THE BERING CHUKCHI SHELF

Time-integrated new production was calculated from estimates of nitrate consumption during summer over the Bering-Chukchi shelf. Time-zero or initial nitrate concentrations were estimated from a highly correlated end-of-winter nitrate-salinity regression. In the southeastern Bering Sea, new production was maximal over the 200 m isobath (>70 g C m-2) and minimal over the inner shelf (<20 g C m-2) in Alaskan Coastal water. Downstream, in the northern Bering and southern Chukchi seas, no additional new production could be resolved in the Alaskan Coastal Water. Anadyr water, on the other hand, supported new production of up to 3.1 g C m-2 day-1 south of Bering Strait and 2.4 g C m-2 day-1 north of the strait. We estimate that over a 120 day growing season 288 g C m-2 year-1 was fixed as new production in this water mass resulting in the removal of 70-90% of the initial nitrate stock. Little additional new production in the Anadyr stream could be expected downstream in the western Chukchi Sea.