Anaerobic methane oxidation is an important sink for methane in the ocean's largest oxygen minimum zone

We investigated methane oxidation in the oxygen minimum zone (OMZ) of the eastern tropical North Pacific (ETNP) off central Mexico. Methane concentrations in the anoxic core of the OMZ reached ~ 20 nmol L −1 at off shelf sites and 34 nmol L −1 at a shelf site. Rates of methane oxidation were determined in ship‐board incubations with 3 H‐labeled methane at O 2 concentrations 0–75 nmol L −1 . In vertical profiles at off‐shelf stations, highest...