Bay Facts

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.

At filter feeders, oysters can filter up to 50 gallons of water a day.

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.

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.

Eighty-six percent of watershed residents believe if people work together, water pollution can be fixed.

Collectively, the Chesapeake’s three largest rivers—the Susquehanna, Potomac and James Rivers—provide more than 80% of the fresh water to the Bay.

The Chesapeake Bay is home to 26 different species of submersed aquatic vegetation (SAV), including freshwater plants, estuarine plants, redhead grass, and marine species.

The word Chesepiooc is an Algonquian word referring to a village "at a big river." In 2005, Algonquian historian Blair Rudes helped dispel the widely-held belief that the name meant “great shellfish bay.”

Water temperatures in the Bay fluctuate widely throughout the year, reaching as high as 84 degrees in summer.

The Chesapeake Bay watershed has 150 major rivers and streams, but contains more than 100,000 smaller tributaries.

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.

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.

The deepest part of the Bay, located southeast of Annapolis near Bloody Point, is called “The Hole” and is 174 feet deep.

The 195-mile-long Rappahannock River is the longest free flowing river in the Chesapeake Bay watershed.

Salinity is highest at the mouth of the Chesapeake Bay, where water from the Atlantic Ocean enters.

The widest point of the Chesapeake Bay measures 35 miles, and is located near the mouth of the Potomac River.

Major rivers emptying into the Bay include the James, York, Rappahannock, Potomac, Patuxent, Patapsco and Susquehanna from the west and the Pocomoke, Wicomico, Nanticoke, Choptank and Chester from the east.