The largest estuary system in the eastern United States and an important blue-crab nursery is Chesapeake Bay.
Chesapeake Bay is a large partially enclosed arm of the Atlantic Ocean between Maryland and Virginia. More than 150 rivers and streams drain into it, creating a watershed that covers parts of six states and Washington, D.C. Freshwater mixing with seawater produces the changing salinity that defines an estuary.
The bay’s shallow waters, marshes, grass beds, and tributary rivers provide food and shelter for young fish and shellfish. Blue crabs are especially associated with Chesapeake Bay, where females release larvae and juveniles grow in protected nursery habitats. The bay also supports oysters, Atlantic menhaden, striped bass, American eels, and numerous waterbirds.
People sometimes confuse Chesapeake Bay with Delaware Bay, another major eastern estuary, or with Puget Sound, which is a large Pacific Northwest marine waterway. Chesapeake Bay is distinguished by its enormous watershed and by its central role in the ecology, fishing economy, and history of the Mid-Atlantic region. Its health is closely tied to nutrient pollution, habitat loss, and restoration efforts.