Continuous Oxygen Monitoring in Buzzards Bay

Team Collaborators

Water’s dissolved oxygen content is critical to estuarine ecosystems—if the level drops too low, even for a short time, it can stress or kill marine life.

Measuring dissolved oxygen can provide key information about the health of an estuary. Dedicated volunteers with the Buzzards Bay Coalition’s Baywatchers program have been measuring dissolved oxygen for over 30 years, sampling more than 20 times each summer at 200 stations across 30 estuaries.

However, dissolved oxygen levels can change rapidly over the course of a day. Low oxygen events can be caused by hot spells, or when windless conditions limit oxygen exchange between the water and the air. Lowest oxygen levels typically occur at night or very early in the morning when algae and aquatic plants are using oxygen and not producing oxygen by photosynthesis. Some of these lows are missed by our current sampling method.

New technology has produced relatively low-cost automated sensors that can continuously measure dissolved oxygen, taking readings every 1, 5, or 15 minutes. These sensors provide large amounts of high-resolution data, and a much clearer picture of an estuary’s health and threats to marine life.

As a new technology, researchers and conservation groups still need to develop methods to deploy and maintain the sensors, manage the large amounts of incoming data, and communicate complex data patterns to people who need the information.

Research area
a woman sits on a boardwalk next to a tube of water, using a dropper to take water out of another small container

photo courtesy of Rachel Jakuba

Our Work

Continuous Oxygen Monitoring in Buzzards Bay is a collaborative project of Woodwell Climate Research Center, the Buzzards Bay Coalition, the University of Massachusetts Amherst, the Woods Hole Oceanographic Institution, and the Onset Computer Corporation.

The COMBB Project tests deploying continuous sensors to measure dissolved oxygen and water quality, engages volunteers with this new technology, and synthesizes the data in a way that is understandable and actionable for local residents, municipal officials, and state regulators who make decisions about water quality.

We will deploy sensors at multiple locations within the West Falmouth, Wareham River, Acushnet River, and Westport River estuaries. With two of these estuaries, we are comparing the performance of sensors placed at fixed locations with sensors deployed on mobile TideRider robots that move up and down the estuaries and up and down in the water column. The project team will develop new procedures to maintain sensors and to check, store, and display the measurement data.

Alongside our work with the sensors, we conduct surveys, interviews, and focus groups to seek input from local communities:

  • We survey water quality monitoring volunteers to learn how they can contribute to new continuous water monitoring as well as traditional methods.
  • We ask town officials about how they can best use the new continuous data.
  • We consult state regulators to make sure the new data can be fed into regulatory processes and used to develop new water quality standards.
a woman works with a plastic tube full of water, inserting it into a wooden block with a hole

photo courtesy of Rachel Jakuba


Locally, COMBB will provide more detailed data on the health of multiple Massachusetts estuaries, and improve our understanding of how dissolved oxygen changes over time in these areas.

More broadly, findings from the project will be shared beyond Buzzards Bay and Massachusetts to help water quality monitoring groups across the U.S. develop methods and best practices for expanding the scope of continuous water quality monitoring.

Support for this project comes from a grant from the National Science Foundation Smart and Connected Communities Program and the Buzzards Bay Coalition.

Partners & Collaborators
  • Buzzards Bay Coalition logo
  • UMass Amherst logo
  • Woods Hole Oceanographic Institution logo
  • Onset Computer Corporation logo

Selected Related Publications

A long-term citizen-assisted dataset of estuarine water quality in Buzzards Bay

Jakuba, R., T. Williams, C. Neill, R. McHorney, L. Scott, B. L. Howes, J. Costa, H. Ducklow, M. Erickson, and M. Rasmussen (2021). Scientific Data


Quantifying the effects of nutrient enrichment and freshwater mixing on coastal ocean acidification

Rheuban, J. E., Doney, S. C., McCorkle,D. C., & Jakuba, R. W (2019). Journal of Geophysical Research Oceans


Spatial and temporal trends in summertime climate and water quality indicators in the coastal embayments of Buzzards Bay, Massachusetts

Rheuban, J. E., S. Williamson, J. E. Costa, D. M. Glover, R. W. Jakuba, D. C. McCorkle, C. Neill, T. Williams and S. C. Doney (2015). Biogeosciences