Diel Oxygen Dynamics in Chesapeake Bay

Malcolm Scully, Applied Ocean Physics & Engineering

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2016 COI Funded Project

Abstract

The rates of gross primary production (GPP) and community respiration (CR) in estuarine and coastal systems provide the link between nutrient inputs and production at higher trophic levels, control the air-sea flux of oxygen and carbon dioxide, and ultimately drive the seasonal depletion of oxygen in bottom waters. Yet, most studies of GPP and CR rely on bottle incubations. The problems associated with these methods are well documented and they are generally unsuitable for making measurements that are highly resolved in time and space. This project seeks funds to apply a novel diel-oxygen technique for estimating GPP and CR to a unique data set consisting of continuous (every 15 minutes) measurements of dissolved oxygen from over 120 locations in Chesapeake Bay. The >120 locations all have continuous data of temperature, salinity, dissolved oxygen, chlorophyll fluorescence, pH and turbidity spanning at least 3-years. The estimates of GPP and CR will provide unprecedented spatial (>120 locations) and temporal resolution (weeks to years) of the fundamental rates of biological productivity in shallow water environments throughout the Bay. The data also will be used to estimate the surface oxygen flux to test the hypothesis that the shallow regions of the Bay are a net source of atmospheric O2 and potentially a net sink of atmospheric CO2.