Method for Quantification of Aquatic Primary Production and Net Ecosystem Metabolism using in situ Dissolved Oxygen Sensors

We present an example-based methodology for the “open-water” technique to determine net ecosystem metabolism (or net community metabolism) of coastal and oceanic environments using dissolved oxygen measurements collected with in situ sensors. We briefly discuss strategies for instrument deployment, data collection, and performance evaluation. The main focus is a presentation of the analytical steps necessary to convert raw dissolved oxygen measurements into daily estimates of primary production, aerobic respiration, and the resulting net metabolic sum. The data manipulation is based on a compilation of approaches from the literature that span multiple decades of research. We provide a summary of the foundational concepts, a brief discussion of the necessary assumptions, and a list of additional variables required for the parameterization of the individual components, such as the air–water diffusion term. The methods are presented in a step-by-step example format using representative data sets from two contrasting environments, the coastal ocean (Monterey Bay, California) and an estuary (Columbia River Estuary, Oregon/Washington).