Bay Facts
The Bay is full of interesting facts and trivia related to its history, wildlife, geography and more.
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 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).
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.
26 different SAV species
The Chesapeake Bay is home to 26 different species of submersed aquatic vegetation (SAV), including freshwater plants, estuarine plants, redhead grass, and marine species.
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.
Majority of striped bass spawn in the Bay
Seventy to ninety percent of all striped bass, known locally as rockfish, were spawned in the Bay.
Learn more500 million pounds of seafood
The Bay produces about 500 million pounds of seafood per year.
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.
1,800 local governments
There are nearly 1,800 local governments in the Bay watershed, including towns, cities, counties and townships.
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 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.
84 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, reaching as high as 84 degrees in summer.
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 moreCan we do more?
Seventy percent of watershed residents want to do more to help make their local creeks, rivers and lakes healthier.
Learn moreFiltering drinking water
Forests and trees help filter and protect the drinking water of 75% of watershed residents.
Learn more80,000 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 moreLongest river fully within Maryland
The 110-mile-long Patuxent River is the longest river to flow exclusively within the borders of Maryland.
What is a watershed?
A watershed is an area of land that drains into a particular river, lake, bay or other body of water.
Learn more18 trillion gallons
The Chesapeake Bay holds more than 18 trillion gallons of water.
Chesapeake National Recreation Area
Legislation proposed by Maryland’s Senator Chris Van Hollen and Representative John Sarbanes to incorporate the bay into the nation’s park system.
10,000 years old
The Chesapeake Bay was formed about 10,000 years ago when glaciers melted and flooded the Susquehanna River valley.
3,600 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 more80% 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.
2 of 5 major ports
Two of the United States’ five major North Atlantic ports—Baltimore and Hampton Roads—are on the Bay.