Chesapeake Bay | WWF

Chesapeake Bay

About the Area

The Chesapeake and Delaware Bay complex is one of the largest estuaries on Earth. Large rivers feed the ecoregion, including the Susquehanna, James, Potomac, Patuxent, and Chester, each bringing nutrients that help make this bay one of the most productive areas on earth.

It contains diverse habitats, each perfectly suited to different plants and animals, making it commercially vital for fisheries, particularly for blue crabs and historically for oysters.

Local Species
Characteristic of this ecoregion is the Atlantic blue crab (Callinectes sapidus), American oyster (Crassostrea virginica), Horseshoe crab (Ilynassa polyphemus), Soft-shelled clam (Mya arenaria), Hard clam (Mercenaria mercenaria), Marsh periwinkle (Littorina irrorata), and Northern diamondback terrapin (Malaclemys terrapin).

Anadromous fish species (those that migrate from freshwater to the ocean and back to freshwater) include American shad (Alosa sapidissima), Atlantic herring (Clupea harengus), Alewife (Alosa pseudoharengus), and Striped bass (Morone saxatilis). Other fish species include the Oyster toadfish (Opsanus tau), Sheepshead minnow (Cyprinodon variegatus), and Marsh killifish (Fundulus confluentes).

Among the many bird species are Clapper rail (Rallus longirostris), Tundra swan (Cygnus columbianus), Atlantic brant (Branta bernicla), Wood duck (Aix sponsa), Hooded merganser (Lophodytes cucullatus), Oldsquaw (Clangula hyemalis), Bufflehead (Bucephala albeola), Green-backed heron (Butorides virescens), Black-crowned night heron (Nycticorax nycticorax), and numerous shorebirds.

High levels of urban development and pollution from agriculture introduce contaminants and cause eutrophication and anoxic conditions (lack of oxygen) in the bay. Introduced species like the Rapa whelk (a large snail originally from Asia) threaten native species, and toxic algal blooms can harm fish and people. Overfishing and habitat destruction represent other disturbance factors.


Habitat type:
Temperate Shelf and Seas

Geographic Location: Eastern North America

Conservation Status:

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