Okuda, C, , Monterey Bay Aquarium Research Institute, Moss Landing, USA, craig@mbari.org
Buck, K, R, Monterey Bay Aquarium Research Institute, Moss Landing, USA, buku@mbari.org
Levesque, C, , Monterey Bay Aquarium Research Institute, Moss Landing, USA, levesque@mbari.org
Barry, J, P, Monterey Bay Aquarium Research Institute, Moss Landing, USA, barry@mbari.org

BENTHIC IN SITU OXYGEN CONSUMPTION MEASURED WITH AN OPTODE-BASED RESPIROMETER

Oxygen consumption by deep-sea sediment community is a fundamental process that relates directly to carbon remineralization and burial rates and other biogeochemical fluxes. Measurements of sediment community oxygen consumption have been made traditionally using incubation chambers enclosing a portion of the seafloor, or from profiles of oxygen levels in the sediment, performed either in situ, or on recovered sediment cores. Each protocol has typically used Clarke-type oxygen electrodes, which have issues with regard to drift, pressure compensation and warm-up times. We have incorporated oxygen optodes into a benthic respirometer, which can be deployed by ROV to abyssal depths. Optode performance has been more robust, accurate and consistent within and between deployments in environments from shallow coastal waters to 1400m. We will discuss the design of the respirometer, the results from numerous deployments and other advanced capabilities recently developed for the benthic respirometer system, including sample injection / withdrawal syringes, pH sensors and a programmable chamber flushing system.