[6] Nutrient pollution and urban runoff have been identified as major components of impaired water quality in the bay stressing ecosystems and compounding the decline of shellfish due to overharvesting.

North of Baltimore, the western shore borders the hilly Piedmont region of Maryland; south of the city the bay lies within the state's low-lying coastal plain, with sedimentary cliffs to the west, and flat islands, winding creeks and marshes to the east.

The bay was formed starting about 10,000 years ago when rising sea levels at the end of the last ice age flooded the Susquehanna River valley.

[22] Birds include ospreys, great blue herons, bald eagles,[23] and peregrine falcons, the last two of which were threatened by DDT; their numbers plummeted but have risen in recent years.

"[39] Other vegetation that makes its home in other parts of the bay are wild rice, various trees like the red maple, loblolly pine and bald cypress, and spartina grass and phragmites.

Their marching route from Newport, Rhode Island through Connecticut, New York State, Pennsylvania, New Jersey and Delaware to the "Head of Elk" by the Susquehanna River along the shores and also partially sailing down the bay to Virginia.

The Chesapeake Bay Flotilla, a fleet of shallow-draft armed barges under the command of U.S. Navy Commodore Joshua Barney, was assembled to stall British shore raids and attacks.

For city folk like me, they're interesting, even exotic –the weather-beaten crabbers and oystermen called "watermen," gentlemen-farmers and sharecroppers, boat builders, antiques dealers – all of whom sound like Southerners with mouthfuls of marbles when they talk.

— Susan Spano, Los Angeles Times, 2008[70]The Chesapeake Bay plays an extremely important role in Maryland, Virginia, and Pennsylvania's economies, in addition to the ecosystem.

[71] In colonial times, simple cooking techniques were used to create one pot meals like ham and potato casserole, clam chowder, or stews with common ingredients like oysters, chicken or venison.

[72] In the 1970s, the Chesapeake Bay was found to contain one of the planet's first identified marine dead zones, where waters were so depleted of oxygen that they were unable to support life, resulting in massive fish kills.

[93] Delaware, Maryland, Virginia, and the District of Columbia adopted WQS for various Chesapeake Bay tributaries in the mid-2000s, referencing the EPA criteria documents, as well as their own extensive data gathering and modeling efforts.

[95] Scientists from the Virginia Institute of Marine Science at the College of William & Mary claim that experimental reefs created in 2004 now house 180 million native oysters, Crassostrea virginica, which is far fewer than the billions that once existed.

The plans include multiple milestone goals for project initiation or continued progress in water quality, through the use of pollution control upgrades (such as at sewage treatment plants) and more widespread utilization of various best management practices (BMPs).

[51] A 2008 Washington Post report suggested that government administrators had overstated progress on cleanup efforts as a way to "preserve the flow of federal and state money to the project.

[112] The health of the Chesapeake Bay improved in 2015, marking three years of gains over a four-year period, according to a 2016 report by the University of Maryland Center for Environmental Science (UMCES).

Projected effects include decreasing dissolved oxygen, more acidic waters making it harder for shellfish to maintain shells and changing the seasonal cycles important for breeding and other lifecycle activities.

[120] Key infrastructure in Virginia, such as the port of Norfolk,[120] and major agriculture and fishing industries of the Eastern Shore of Maryland will be directly impacted by the changes in the bay.

The sediment record of the Chesapeake Bay shows a major increase in nutrient levels, suggesting limited availability of oxygen, starting between the 17th and 18th centuries (Cooper & Brush 1991; Zimmerman & Canuel, 2002).

More sunlight, higher temperatures, and less storms and winds during the summer cause strongly stratified water column, with a pycnocline typically 10 meters below the surface (Cerco & Noel; Seliger et al.).

Researchers work in the Chesapeake Bay to collect information about water quality, plant and animal abundances, shoreline erosion, tides, waves, and harmful algal blooms.

Monitoring programs set out instruments at fixed stations on buoys, moorings, and docks throughout the bay to record things like temperature, salinity, chlorophyll-a concentration, dissolved oxygen, and turbidity over time.

Ranging from 12,000-year-old, precolonial native settlements to shipwrecks from as recent as World War II, the MMAP researches thousands of years' worth of history in these archaeological sites.

Along with environmental factors, the bay has been negatively impacted by humans since being settled in the 17th century, bringing with them problems like pollution, construction, destruction of the environment, and currently poultry farms.

As sea levels rise and historically significant areas are sunk and covered in sediment, the MMAP relies on various pieces of equipment to locate these man-made anomalies but also ensure that the material being examined is kept intact.

"[128] Still, the MMAP makes it a point to publish their data and information once a site is officially identified; however, the details of the location are left out to sway would-be looters, who have plagued marine archaeologists for decades.

[129] Dozens of precolonial era canoes and artifacts have been extracted from the bay, helping to portray a better picture of the lives of Native Americans (e.g., Powhatan, Pamunkey, Nansemond) In 1974, scallop fishermen dredged up the skull of a prehistoric mastodon, which through carbon dating was found to be 22,000 years old.

The Solutrean hypothesis challenges the previous theory regarding the first inhabitants of North America, whereas it is commonly accepted amongst anthropologists that the Clovis people were the first to settle the region somewhere around 13,000 years ago.

In 1982, the Virginia Department of Historic Resources along with the first State Underwater Archaeologist, John Broadwater, led an expedition to explore and research a sunken fleet of Revolution-era battleships.

Virginia has recently been granted funding for further research of these sunken vessels and expeditions are currently underway with the goal to fully explore this destroyed fleet of British ships.