Benthic Respirometer Upgrade
Project Manager/Lead Scientist: Jim Barry
Our project to upgrade the benthic respirometer (BRS) will increase the scope of measurements relating to carbon cycling and benthic community energetics. Studies of carbon cycling in marine sedimentary communities have relied principally on measurements of oxygen uptake, using respiration chambers placed on the seafloor. In the past such chambers typically had a single oxygen sensor.
The upgraded system will have three sensors—oxygen, carbon dioxide, and pH—and five sample injection or withdrawal syringes. The optical sensors (optrodes) and a temperature sensor will be housed in each of three respiration chambers. The oxygen optrode will be changed from an “intensity-based” measurement to a “life-time” based measure, to minimize instrument drift and simplify calibration. Respiration chambers will be modified to allow measurements of individual animals, including adaptation to fit the present detritus sampler design. A single sensor head will be fit to various chamber designs (core, benthic animal, midwater animal). The Oasis 3 control system will be adapted for use with the respirometer and will replace the osmoanalyzer-based TT4 controller.The upgraded BRS will support more detailed study of benthic carbon cycling and physiological studies of individual benthic and midwater animals. The addition of carbon dioxide and pH sensors will also support studies of the biological impacts of carbon dioxide sequestration.