Nitrous Oxide Consumption in Oxygenated and Anoxic Estuarine Waters

Estuaries emit a large but highly uncertain amount of N2O into the atmosphere. To better understand cycling processes in estuaries, we provide first direct observations consumption seasonally anoxic Chesapeake Bay, largest estuary United States. rates waters reached up to 3.3 nmol L-1 d-1 were generally undetectable oxygenated waters. However, substantially enhanced when oxygen concentration was experimentally decreased initially samples, indicating potential environments, e.g., surface These followed Michaelis-Menten kinetics as function increasing substrate concentration. N2O-consuming microbes that predominantly contained clade II nitrous oxide reductase gene detected throughout water column. new environmental controls on will benefit modeling and help constrain estuarine flux.