Patuxent Sentinel river monitoring program expands

September 13, 2018

Real-time environmental monitoring of the Patuxent River provides dual scientific and public services

The Chesapeake Biological Laboratory research pier extends 750 feet into the Patuxent River from Solomons Island.

Do you want to know what the winds, tide, or water temperature are before heading out on the water? Are you an educator or scientist looking to explore the relationships between water chemistry, physics, and biology in the Patuxent River? The Chesapeake Biological Laboratory’s Patuxent Sentinel provides a comprehensive environmental monitoring system for our local tributary to the Chesapeake Bay.

The University of Maryland Center for Environmental Science (UMCES) has launched a new monitoring system at the Chesapeake Biological Laboratory to measure chemical, physical, and biological properties in the Patuxent River. Deployed off of the research pier on Solomons Island, the Patuxent Sentinel system of sensors provides real-time information on water temperature, salinity, tide heights, current velocity, wind speeds, dissolved oxygen, and other environmental measurements.

With support from the National Science Foundation and linkages to nearby federal measurement platforms, such as the National Oceanic and Atmospheric Administration’s tide and weather data and the U.S. Geological Survey’s stream gauging, UMCES is able to provide a full suite of locally relevant environmental measurements to scientists and the public.

In the example above, dissolved oxygen conditions on the CBL pier are measured every 15 minutes and illustrated over a seven-day period, including the real-time conditions. Improved graphing, data access, and expanded measurement capabilities incorporate

This monitoring program builds on the Chesapeake Biological Laboratory's long history of water monitoring in the Patuxent River, including a record of daily temperature and salinity dating back to 1938. Scientists will be using this data to continue the historic monitoring program and to support new scientific analyses of the Patuxent River, including water conditions associated with bay grasses, long-term changes in water temperature, and tracking changes in water quality associated with watershed remediation activities, like nutrient management plans.

 “Many of the important discoveries in the past year related to Chesapeake Bay water quality have been based upon sustained, comprehensive monitoring efforts,” says Dr. Jeremy Testa, an Assistant Professor at CBL who led the development of the Patuxent Sentinel system. “We aim to build additional capacity in the Patuxent by measuring and reporting these data in real-time.”

The data from the Patuxent Sentinel are freely available at in a variety of forms, including a website that communicates real time conditions for the water and boating community, as well data download features for those interested in more details of the data record, such as educators.

Questions about the Patuxent Sentinel can be directed to Dr. Jeremy Testa at the Chesapeake Biological Laboratory (