The NOAA Chesapeake Bay Office operates a system of sensors that track dissolved oxygen (DO), conductivity, salinity, and water temperatures throughout the water column at locations around the Chesapeake Bay. These “DO buoys” help scientists learn more about the Chesapeake’s water column.
Map of the locations of NCBO DO buoys in 2024. Locations vary from year to year.
At each location, a buoy is anchored to the bottom. An inductive cable connects the anchor to the buoy. Along the cable, sensors are stationed every few meters that track water-quality parameters. Data from the sensors are sent to a computer in the buoy via the inductive cable. The buoy sends data back to a shoreside database using a cellular modem. A solar panel and batteries power the buoy’s operations.
Diagram of a DO buoy.
Measuring and tracking hypoxia—very low levels of dissolved oxygen in the water—helps scientists more fully understand how levels vary from the surface to the bottom, and how they change hour by hour throughout the year. This information improves the results of modeling of the “dead zone” of hypoxic water in the Chesapeake. Data from these buoys help the Chesapeake Bay Program determine whether it is meeting water-quality goals, and whether restoration work is having an effect. Fisheries scientists can use the data to learn more about the effects of hypoxia and changes in water conditions on different species, because the water column provides important fish habitat.