The Chesapeake Bay is the largest estuary in the United States.

The Chesapeake Bay
is the largest estuary in the United States and is one of the most productive bodies of water in the world.

The Chesapeake watershed* spans 64,000 squares miles, covering parts of six states — Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia, and the District of Columbia. Over 17 million people live in this area.

(*A watershed is the area of land where all of the water that is under it or drains off of it goes into the same place.)

The estuary and its network of streams, creeks and rivers hold tremendous ecological, cultural, economic, historic, and recreational value for the region.

More than 250 fish species use the Bay and tributaries for some portion of their life cycles, including American and hickory shad, river herring, striped bass, eel, weakfish, bluefish, flounder, oysters, and blue crabs. More than 300 migratory bird species can also be found in the watershed. During the fall, the skies come alive as one million ducks, geese, and swans return to overwinter on the Chesapeake.

The Chesapeake watershed is a complex network of wetlands, forests, fields, streams, underwater grasses, and mudflats that provide thousands of species of plants, fish, and wildlife with the places they need to find food, shelter, reproduce, and rear their young. The Chesapeake also provides "habitat highways" for Atlantic Coast fish populations and birds migrating along the Atlantic Flyway. These habitats play an important role in filtering pollution before it enters waterways.

Bay wetlands serve as holding tanks and water filters for coastal storm surge and heavy rainfall and help prevent costly flood damage. Forest buffers along streams and shorelines provide shade to keep streams cool, food for aquatic organisms and corridors for wildlife movement. Streams are the arteries that connect the watershed and provide not only passage for fish, but also a physical connection from every local community to the Bay.

Today, the Bay and its tributaries are in poor health, with polluted water, low populations of fish and shellfish, degraded habitats, and landscapes lost to development. In recognition of this, President Obama issued an Executive Order in 2009 to protect and restore this important area. In the Order, the President declared the Chesapeake Bay a "national treasure" and ushered in a new era of federal leadership, action and accountability to "protect and restore the health, heritage, natural resources, and social and economic value of the nation's largest estuarine ecosystem and the natural sustainability of its watershed."