Bay Facts
The Bay is full of interesting facts and trivia related to its history, wildlife, geography and more.
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.
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.
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 more60% 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 more29 species of waterfowl
The Chesapeake region is home to at least 29 species of waterfowl.
Learn moreFirst recorded European to enter the Bay
In 1524, Italian Captain Giovanni da Verrazano became the first recorded European to enter the Chesapeake Bay.
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.
51 billion gallons
Approximately 51 billion gallons of water flow into the Bay each day from its freshwater tributaries.
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 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.
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 more100,000 smaller tributaries
The Chesapeake Bay watershed has 150 major rivers and streams, but contains more than 100,000 smaller tributaries.
Volunteering with environmental organizations
While one-third of watershed residents have volunteered their time or donated their money to a charitable organization, less than two in ten volunteers have done so for an environmental organization.
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.
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 more2 of 5 major ports
Two of the United States’ five major North Atlantic ports—Baltimore and Hampton Roads—are on the Bay.
Filtering drinking water
Forests and trees help filter and protect the drinking water of 75% of watershed residents.
Learn more6,282,718 acres of greenspace
There are 6,282,718 acres of accessible green space within the Chesapeake Bay watershed.
84 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, reaching as high as 84 degrees in summer.
200 miles long
The Bay itself is about 200 miles long, stretching from Havre de Grace, Maryland, to Virginia Beach, Virginia.
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.
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.
34 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, dropping as low as 34 degrees in winter.
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.