Oxygen utilization and plankton metabolism in a Washington fjord

Abstract

Oxygen utilization in the bottom waters of Dabob Bay, Washington, was measured by the time course of oxygen and compared to the metabolic activity of the net zooplankton and microplankton. Neither fraction of plankton could be neglected as unimportant and together they accounted for 70–85% of the oxygen consumption in the bay. The rate of oxygen utilization for the summer of 1973 was 1.25 μg-at O day−1 1−, 12% higher than the rate measured 19 years earlier. At this rate, the deep waters (bottom 50 m) were responsible for the oxidation of 36% of the bay's summer primary productivity.