As of 2019, are there any dolphins in the Potomac River ?

The Potomac River is found within the Mid-Atlantic region of the United States and flows from the Potomac Highlands into the Chesapeake Bay. The river is approximately 405 miles (652 km) long, with a drainage area of about 14,700 square miles (38,000 km). In terms of area, this makes the Potomac River the fourth largest river along the Atlantic coast of the United States and the 21st largest in the United States. Over 5 million people live within the Potomac watershed. George Washington named the Potomac river "The Nation's River".

In 1965 President Lyndon B. Johnson declared the Potomac river "a national disgrace". Starting from the 1960s, the river became contaminated by algae, trash and human waste, causing it to lose its natural inhabitants, including dolphins and bald eagles –the State National Symbol– that lived on its shores.

More than 50 years of pollution control, clean-up and restoration efforts gave some noticeable results. In 2015 around 200 dolphins were observed by researchers from Georgetown University’s Potomac-Chesapeake Dolphin Project. In 2019 population has reached more than 1,000 individuals, with several small groups of 200 dolphins hanging out in the river. Some have swam upstream within 50 miles of Washington, D.C. In August 2019 researchers witnessed a dolphin giving birth in the river. It was one of only three times scientists have seen a bottlenose dolphin giving birth in the wild anywhere.