Comparison of three pH sensors co-deployed in a high variability environment

• Main Authors: Love, Brooke, Bohlmann, Heath
• Format: Text
• Language: English
• Published: Western CEDAR 2016
• Subjects: Fresh Water Studies; Life Sciences; Marine Biology; Natural Resources and Conservation; Bayview; Ocean acidification
• Online Access: https://cedar.wwu.edu/ssec/2016ssec/climate_change_ocean_acidification/59

Three pH sensors were deployed in a channel in Padilla Bay for several multiple week deployments both in winter and summer seasons. One sensor (a YSI EXO sonde) is part of the long term monitoring of the Padilla Bay National Estuarine Research Reserve. The second sensor is a Satlantic SeaFET, and is part of the Washington Ocean Acidification Center’s monitoring effort. The third sensor is a custom built sensor based on the DuraFET sensor, and identical in design to the suite of sensors in use at the Washington Department of Natural Resources for nearshore monitoring. The sensors were each deployed in individual pvc pipes with large cutouts at the bottom to allow free water flow around the sensor head. The pipes are affixed to a single piling in the bayview channel which drains extensive eelgrass beds. Flow is generally vigorous in the channel and sensors were deployed about 1 meter above the bottom. The pH varies by as much as a full pH unit across a few hours under certain conditions at this location, providing a wide range across which to compare the sensors. The relative performance of these three sensors will be of interest to practitioners wishing to assess data collected with similar sensors across different environments.