ESTIMATES OF DENITRIFICATION IN SEDIMENTS OF THE BERING SEA SHELF

Denitrification, i.e. anaerobic reduction of nitrate or nitrite to gaseous nitrogen, in the surface sediments of the Bering Sea was estimated using a 15N-tracer method. N2 production is apparently controlled by the supply of nitrate and nitrite to the sediments. The average rate of N2 production in three locations was 1.2 ng-atoms N (g dry weight of sediment)-1 h-1. The rate of nitrate reduction estimated from the vertical distribution of nitrate in the sediments using a one-dimensional diffusion model agreed well with observed rates of N2 production. The annual loss of combined nitrogen by denitrification in the Bering Sea shelf was estimated to be 5 × 1011 g. © 1979.