Dolphins Return to the Chesapeake Bay and Its Rivers, and Boaters Can Help Scientists Track Them

As the weather warms, dolphins are heading back to their favorite corners of the Chesapeake Bay, much as many families in the Washington area do each summer. Scientists know about these habits in part because of the Chesapeake Dolphin Watch app, which has been in use since 2017.

Thomas Miller, a professor at the University of Maryland Center for Environmental Science (UMCES), told WTOP that researchers first picked up the presence of bottlenose dolphins in the bay and its tributaries in 2015, using underwater microphones. The team wanted to learn more about how the animals move through the region, but it needed a way to collect much more data than the equipment alone could provide.

The answer, Miller said, was to draw on the many people who spend time on the water in spring and summer, including boaters and anglers. "And so we launched the app in 2017, and it has been improved upon ever since," Miller said. "The people who use the dolphin watch app report sightings that we can validate."

More than 7,000 sightings have been reported since the app debuted. Miller said parts of the upper Chesapeake appear to serve as a nursery, as people in that area often see mothers with their young.

The dolphins follow shoals of fish into shallower water, which can bring them close to developed areas. "They certainly do use habitats that we think of as urban, city areas," Miller said. The animals spend the winter in waters south of Norfolk, Virginia, and travel north once the water warms in spring. "We've seen them in to almost the Inner Harbor in Baltimore and we've seen them north of the 301 bridge in the Potomac," Miller said.

Anyone can register for the app and record the date, time, GPS location and number of dolphins they see. Users can also attach videos and photos. The app shows all users where others have spotted the animals around the bay.

Miller encouraged people to take part but urged care when making observations. "We want to encourage people to watch dolphins, but we also ask that people keep a very respectful distance from these just amazing animals," he said.

People who want to follow along can find "Chesapeake DolphinWatch" on Facebook or @dolphinwatch_cb on Instagram. The accounts post about sightings and share information about dolphins, along with interactive quizzes and polls.