Bay Facts
The Bay is full of interesting facts and trivia related to its history, wildlife, geography and more.
4,480 square miles of surface area
The surface area of the Bay and its tidal tributaries is approximately 4,480 square miles.
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.
34 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, dropping as low as 34 degrees in winter.
One million waterfowl
Nearly one million waterfowl winter on the Bay–approximately one-third of the Atlantic coast’s migratory population. The birds stop to feed and rest on the Bay during their annual migration along the Atlantic Migratory Bird Flyway.
Learn more10,000 years old
The Chesapeake Bay was formed about 10,000 years ago when glaciers melted and flooded the Susquehanna River valley.
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.
Avoiding toxic pesticides
Forty-six percent of watershed residents never use toxic pesticides in or around their homes. You can evaluate a pesticide’s toxicity to judge the risk in using it, or make your own non-toxic pesticide with garlic, vinegar, cooking oil and other common household items.
60% of Chesapeake forests
Sixty percent of Chesapeake forests have been divided into disconnected fragments by roads, homes and other gaps that are too wide or dangerous for wildlife to cross.
Learn moreFormally recognized tribes in Maryland
The State of Maryland has formally recognized three tribes: the Piscataway Indian Nation, Piscataway Conoy Tribe and the Accohannock Indian Tribe.
Learn more11,684 miles of shoreline
The Bay and its tidal tributaries have 11,684 miles of shoreline—more than the entire U.S. west coast.
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 more2 of 5 major ports
Two of the United States’ five major North Atlantic ports—Baltimore and Hampton Roads—are on the Bay.
Captain John Smith visits the Bay
In 1608, Captain John Smith set off on the first of two voyages where he charted the land and waterways, and later drew an elaborate and remarkably accurate map of the Chesapeake Bay.
Learn moreHow we can fix water pollution
Eighty-six percent of watershed residents believe if people work together, water pollution can be fixed.
First recorded European to enter the Bay
In 1524, Italian Captain Giovanni da Verrazano became the first recorded European to enter the Chesapeake Bay.
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 more3,600 species of plants and animals
The Bay supports more than 3,600 species of plants and animals, including 348 species of finfish, 173 species of shellfish, over 2,700 plant species and more than 16 species of underwater grasses.
Learn moreThe Bay's largest tributary
The Susquehanna River is the Bay’s largest tributary, and contributes about half of the Bay’s freshwater (about 19 million gallons per minute).
Filtering up to 50 gallons of water a day
At filter feeders, oysters can filter up to 50 gallons of water a day.
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.
The Powhatan tribes
There were many different tribes in the region before Europeans arrived, but the dominant group were Algonquian speakers known collectively as the Powhatan tribes.
Longest free flowing river in the Bay watershed
The 195-mile-long Rappahannock River is the longest free flowing river in the Chesapeake Bay watershed.
9.6 million acres of land
Approximately 9.6 million acres of land in the Bay watershed have been permanently protected from development by Bay Program partners.
Learn more12 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.