Bay Facts
The Bay is full of interesting facts and trivia related to its history, wildlife, geography and more.
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 miles wide
The widest point of the Chesapeake Bay measures 35 miles, and is located near the mouth of the Potomac River.
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 moreFiltering up to 50 gallons of water a day
At filter feeders, oysters can filter up to 50 gallons of water a day.
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 moreWhat 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.
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.
Six states and the District of Columbia
The Chesapeake Bay watershed stretches approximately 524 miles from Cooperstown, New York, to Norfolk, Virginia. It includes parts of six states—Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia—and the entire District of Columbia.
Three geologic regions
The Chesapeake Bay watershed contains three distinct geologic regions: the Atlantic coastal plain, the Piedmont plateau and the Appalachian province.
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.
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.
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 more34 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, dropping as low as 34 degrees in winter.
29 species of waterfowl
The Chesapeake region is home to at least 29 species of waterfowl.
Learn more500 million pounds of seafood
The Bay produces about 500 million pounds of seafood per year.
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.
284,000 acres of tidal wetlands
Approximately 284,000 acres of tidal wetlands grow the Chesapeake Bay region. Wetlands provide critical habitat for fish, birds, crabs and many other species.
Learn more1,300 access sites
There are more than 1,300 public access sites on the Chesapeake Bay and its tributaries.
Learn moreFiltering drinking water
Forests and trees help filter and protect the drinking water of 75% of watershed residents.
Learn more85% of airborne nitrogen
Healthy forests can capture more than 85% of the nitrogen that falls onto them from the air.
4,863 feet above sea level
At 4,863 feet above sea level, Spruce Knob is the highest point in the Chesapeake watershed.
4-30 mile width
The Bay’s width ranges from four miles near Aberdeen, Maryland, to 30 miles near cape Charles, Virginia.
200 invasive species
There are as many as 200 invasive species present in the Chesapeake Bay watershed that are causing some serious issues in an already-stressed ecosystem. Some examples include blue catfish, snakehead, zebra mussel, purple loosestrife, and nutria.
10,000 years old
The Chesapeake Bay was formed about 10,000 years ago when glaciers melted and flooded the Susquehanna River valley.