Methane oxidation in Cape Lookout Bight, North Carolina 1

Abstract

Aerobic methane oxidation rates in seawater from Cape Lookout Bight, determined in the laboratory by concentration changes during incubation at 25° ± 0.5°C, averaged 0.010 ± 0.008 µM d−1 when oxygen was high (>90 µM) and dissolved inorganic nitrogen concentrations were below 14 µM, typical of chemical conditions in the bight water column. When DIN concentrations exceeded 15–16 µM with oxygen the same, the methane oxidation rate averaged 0.210 ± 0.026 µM d−1, suggesting that the methane‐oxidizing bacteria isolated from bight waters were facultative microaerophiles like those found in freshwaters. The results of an in situ incubation experiment agreed with those of the laboratory studies.