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.
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.
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.
174 feet deep
The deepest part of the Bay, located southeast of Annapolis near Bloody Point, is called “The Hole” and is 174 feet deep.
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).
1.6 billion pounds of blue crabs
Since 1990, commercial watermen have harvested more than 1.6 billion pounds of blue crabs from the Bay. Data show commercial harvest has experienced a steady decline, and in 2014 hit the lowest level recorded in 25 years: 35 million pounds.
Learn more4,863 feet above sea level
At 4,863 feet above sea level, Spruce Knob is the highest point in the Chesapeake 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 more18 trillion gallons
The Chesapeake Bay holds more than 18 trillion gallons of water.
34 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, dropping as low as 34 degrees in winter.
Reducing runoff
Fourteen percent of watershed residents use rain barrels to collect rainwater from their downspouts and keep runoff out of rivers and streams. While water collected in rain barrels is not safe to drink, it can be used to water plants or wash cars.
Learn more9.6 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 more500 million pounds of seafood
The Bay produces about 500 million pounds of seafood per year.
What is a shallop?
Captain John Smith and his men sailed the Chesapeake Bay in a modest wooden boat called a shallop–an open wooden workboat such as a barge, dory, or rowboat that was small enough to row but also had one or two sails.
12 species of shark
There are twelve known species of shark that have been sighted in the Chesapeake Bay, with only five considered a common occurrence—smooth dogfish, sand tiger shark, sandbar shark, spiny dogfish, and bull shark.
12 miles wide
The mouth of the Chesapeake Bay is about 12 miles wide between its northern point near Cape Charles, Virginia, and its southern point close to Cape Henry, Virginia.
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.
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.
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 moreLitter bugs
Nine in ten watershed residents never toss food wrappers, cups or cigarette butts on the ground. Almost eight in ten watershed residents pick up litter when they see it.
4-30 mile width
The Bay’s width ranges from four miles near Aberdeen, Maryland, to 30 miles near cape Charles, Virginia.
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 moreFiltering up to 50 gallons of water a day
At filter feeders, oysters can filter up to 50 gallons of water a day.
100,000 smaller tributaries
The Chesapeake Bay watershed has 150 major rivers and streams, but contains more than 100,000 smaller tributaries.