Bay Facts
The Bay is full of interesting facts and trivia related to its history, wildlife, geography and more.
64,000 square miles
The area of the watershed is about 64,000 square miles.
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.
1,800 local governments
There are nearly 1,800 local governments in the Bay watershed, including towns, cities, counties and townships.
Largest 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.
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 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 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.
84 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, reaching as high as 84 degrees in summer.
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.
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.
35.5 million years
The formation of the Chesapeake Bay happened 35.5 million years ago when a meteor collided with Earth, forming a massive crater.
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 moreThree geologic regions
The Chesapeake Bay watershed contains three distinct geologic regions: the Atlantic coastal plain, the Piedmont plateau and the Appalachian province.
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.
The 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).
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.
34 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, dropping as low as 34 degrees in winter.
4,480 square miles of surface area
The surface area of the Bay and its tidal tributaries is approximately 4,480 square miles.
Replacing grass lawn with native plants
Twenty-six percent of watershed residents have replaced an area of their grass lawn with native plants. Native plants provide food and habitat to bees, birds and butterflies, and often don’t need to be watered or fertilized.
Learn more87 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.
6,282,718 acres of greenspace
There are 6,282,718 acres of accessible green space within the Chesapeake Bay watershed.
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 moreHow we can fix water pollution
Eighty-six percent of watershed residents believe if people work together, water pollution can be fixed.
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.
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