%ABourbonnais, Annie%AFrey, Claudia%ASun, Xin%ABristow, Laura%AJayakumar, Amal%AOstrom, Nathaniel%ACasciotti, Karen%AWard, Bess%Anull Ed.%BJournal Name: Frontiers in Marine Science; Journal Volume: 8 %D2021%I %JJournal Name: Frontiers in Marine Science; Journal Volume: 8 %K %MOSTI ID: 10280249 %PMedium: X %TProtocols for Assessing Transformation Rates of Nitrous Oxide in the Water Column %XNitrous oxide (N 2 O) is a potent greenhouse gas and an ozone destroying substance. Yet, clear step-by-step protocols to measure N 2 O transformation rates in freshwater and marine environments are still lacking, challenging inter-comparability efforts. Here we present detailed protocols currently used by leading experts in the field to measure water-column N 2 O production and consumption rates in both marine and other aquatic environments. We present example 15 N-tracer incubation experiments in marine environments as well as templates to calculate both N 2 O production and consumption rates. We discuss important considerations and recommendations regarding (1) precautions to prevent oxygen (O 2 ) contamination during low-oxygen and anoxic incubations, (2) preferred bottles and stoppers, (3) procedures for 15 N-tracer addition, and (4) the choice of a fixative. We finally discuss data reporting and archiving. We expect these protocols will make 15 N-labeled N 2 O transformation rate measurements more accessible to the wider community and facilitate future inter-comparison between different laboratories. %0Journal Article