Bay Facts
The Bay is full of interesting facts and trivia related to its history, wildlife, geography and more.
21 feet deep
The Bay is surprisingly shallow. Its average depth, including all tidal tributaries, is about 21 feet. A person who is six feet tall could wade through more than 700,000 acres of the Bay and never get his or her hat wet.
Where 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.
87 species of waterbirds
During the winter, the Bay supports 87 species of waterbirds. Of these wintering waterbirds, 14 species rely on the Bay to serve as habitat for more than 10% of their continental populations.
Getting 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 more35.5 million years
The formation of the Chesapeake Bay happened 35.5 million years ago when a meteor collided with Earth, forming a massive crater.
34 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, dropping as low as 34 degrees in winter.
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 more6,282,718 acres of greenspace
There are 6,282,718 acres of accessible green space within the Chesapeake Bay watershed.
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.
Bald eagle recovery in the Chesapeake
In the 1970’s, there were as few as 60 breeding pairs of bald eagles in the entire Bay region. Today, as much as 3,000 breeding pairs of bald eagles can be found.
Learn moreLargest land-to-water ratio in the world
The Chesapeake Bay’s land-to-water ratio is 14:1: the largest of any coastal water body in the world. This is why our actions on land have such a big impact on the Bay’s health.
10 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.
More than 200 historic shipwrecks
Mallows Bay is the final resting place for more than 200 historic shipwrecks dating back to the Revolutionary War. Commonly referred to as the “Ghost Fleet” of Mallows Bay, it is the largest collection of shipwrecks in the Western Hemisphere.
84 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, reaching as high as 84 degrees in summer.
Longest river fully within Maryland
The 110-mile-long Patuxent River is the longest river to flow exclusively within the borders of Maryland.
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.
1,300 access sites
There are more than 1,300 public access sites on the Chesapeake Bay and its tributaries.
Learn moreThree geologic regions
The Chesapeake Bay watershed contains three distinct geologic regions: the Atlantic coastal plain, the Piedmont plateau and the Appalachian province.
18 trillion gallons
The Chesapeake Bay holds more than 18 trillion gallons of water.
Reducing runoff
Fourteen percent of watershed residents use rain barrels to collect rainwater from their downspouts and keep runoff out of rivers and streams. While water collected in rain barrels is not safe to drink, it can be used to water plants or wash cars.
Learn moreHow we can fix water pollution
Eighty-six percent of watershed residents believe if people work together, water pollution can be fixed.
Remnants of an ancient river
A few deep troughs run along much of the Bay’s length and are believed to be remnants of the ancient Susquehanna River.
First recorded European to enter the Bay
In 1524, Italian Captain Giovanni da Verrazano became the first recorded European to enter the Chesapeake Bay.
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.
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