Bay Facts
The Bay is full of interesting facts and trivia related to its history, wildlife, geography and more.
80,000 acres of underwater grasses
Nearly 80,000 acres of underwater grasses grow in the shallows of the Chesapeake Bay and its tributaries. Young and molting blue crabs rely on underwater grass beds for protection from predators.
Learn more1,300 public access points
There are more than 1,300 public access points on the Chesapeake Bay and its tributaries.
Learn more12 species of shark
There are twelve known species of shark that have been sighted in the Chesapeake Bay, with only five considered a common occurrence—smooth dogfish, sand tiger shark, sandbar shark, spiny dogfish, and bull shark.
10,000 years old
The Chesapeake Bay was formed about 10,000 years ago when glaciers melted and flooded the Susquehanna River valley.
12 major rivers
Major rivers emptying into the Bay include the James, York, Rappahannock, Potomac, Patuxent, Patapsco and Susquehanna from the west and the Pocomoke, Wicomico, Nanticoke, Choptank and Chester from the east.
80% of the Bay's freshwater
Collectively, the Chesapeake’s three largest rivers—the Susquehanna, Potomac and James Rivers—provide more than 80% of the fresh water to the Bay.
18.5 million people
The Chesapeake Bay watershed is home to more than 18 and a half million people. Ten million of them live along or near the Bay’s shores. About 150,000 new people move into the Bay watershed each year.
Learn moreWhat is a shallop?
Captain John Smith and his men sailed the Chesapeake Bay in a modest wooden boat called a shallop–an open wooden workboat such as a barge, dory, or rowboat that was small enough to row but also had one or two sails.
500,000 Canada geese
More than 500,000 Canada geese winter in and near the Bay.
Learn more4,480 square miles of surface area
The surface area of the Bay and its tidal tributaries is approximately 4,480 square miles.
What is brackish water?
Most of the water in the Bay, including in the middle portion of the Bay and its tidal rivers, is brackish–a mixture of salty and fresh, with a salinity level of greater than 0.5 ppt but less than 25 ppt.
11,684 miles of shoreline
The Bay and its tidal tributaries have 11,684 miles of shoreline—more than the entire U.S. west coast.
Saltiest part of the Bay
Salinity is highest at the mouth of the Chesapeake Bay, where water from the Atlantic Ocean enters.
Largest estuary in the United States
The Chesapeake Bay is an estuary: a body of water where fresh and salt water mix. It is the largest of more than 100 estuaries in the United States and third largest in the world.
Learn moreFormally recognized tribes in Virginia
The Commonwealth of Virginia has formally recognized 11 tribes. Among them, the Pamunkey tribe was the first Virginia tribe to be recognized by the federal government.
Learn moreWhere does the Bay get its water?
The Bay receives about half its water volume from the Atlantic Ocean in the form of saltwater. The other half (freshwater) drains into the Bay from the enormous 64,000-square-mile watershed.
100,000 smaller tributaries
The Chesapeake Bay watershed has 150 major rivers and streams, but contains more than 100,000 smaller tributaries.
The Chesapeake Bay's first inhabitants
The first inhabitants of the Chesapeake Bay region are referred to as Paleo-Indians. They came more than 10,000 years ago from other parts of North America, drawn in by the abundance of wildlife and waterways.
Learn moreGetting oxygen underwater
Just like those on land, animals in the Chesapeake Bay need oxygen to survive. Oxygen is present underwater in dissolved form, and in order to thrive, animals like blue crabs need dissolved oxygen concentrations of three milligrams per liter.
Learn more10 U.S. presidents
There have been 10 U.S. presidents from the Chesapeake Bay watershed, including George Washington, Thomas Jefferson, James Madison, James Monroe, William Henry Harrison, John Tyler, Zachary Taylor, Woodrow Wilson, James Buchanan and Joe Biden.
Three geologic regions
The Chesapeake Bay watershed contains three distinct geologic regions: the Atlantic coastal plain, the Piedmont plateau and the Appalachian province.
Filtering up to 50 gallons of water a day
At filter feeders, oysters can filter up to 50 gallons of water a day.
70 acres of forest lost each day
Forests cover 55% of the Chesapeake Bay watershed. Between 1990 and 2005, the watershed lost an estimated 100 acres of forest land each day. While this rate fell in 2006 to an estimated 70 acres per day, this rate is still unsustainable.
Learn more1,800 sunken vessels
More than 1,800 vessels have met their end in Bay waters, lying broken and battered on the Bay's floor.