Molecular Biological Technologies for Ocean Sensing

Abstract

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 brie fl y 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 respira-tion, 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 environ-ments, the coastal ocean (Monterey Bay, California) and an estuary (Columbia River Estuary, Oregon/ Washington). This chapter provides the methodology for the collection and analysis of high-resolution in situ dissolved O 2 (DO) measurements for determining net ecosystem metabolism (NEM), net ecosystem production (NEP), gross primary production (GPP), and ecosys-tem respiration (ER) of coastal and estuarine aquatic ecosystems. We focus on the " open-water " or " diel oxygen " techniques