The Chesapeake Bay is the nation's largest estuary, covering approximately 2,500 square miles. It is the largest and most biologically productive estuary in the world, including the District of Columbia and large portions of Maryland, Virginia, Pennsylvania, New York, Delaware, and West Virginia. The bay is home to more than 17,000 people, including the District of Columbia and large portions of Maryland, Virginia, Pennsylvania, New York, Delaware, and West Virginia. The bay is a source of drinking water, food, power, recreation, and jobs, and its three-sixth of a million species of plants and animals rely on the bay's unique blend of freshwater and saltwater habitats.