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Discover the Chesapeake

The Chesapeake Bay - the largest estuary in the United States - is an incredibly complex ecosystem that includes important habitats and food webs. The Bay and its rivers, wetlands and forests provide homes, food and protection for diverse groups of animals and plants. Fish of all types and sizes either live in the Bay and its tributaries year-round or visit its waters as they migrate along the East Coast.

Bay 101

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Bay 101: Emerald Ash Borer

Learn about efforts to curb the invasive insect that is decimating ash trees

The Chesapeake Bay Watershed

A watershed is an area of land that drains to a particular river, lake, bay or other body of water. Watersheds are sometimes called “basins” or "drainage basins."

We all live in a watershed. Some watersheds, like that of your local stream or creek, are small. Others, like the Chesapeake Bay watershed, are very large. Learn more about the Chesapeake Bay watershed.

The Bay Ecosystem

An ecosystem is a complex set of relationships among living and non-living things. Air, water, soil, sunlight, plants and animals – including humans – make up an ecosystem. Ecosystems can be as tiny as a patch of dirt in your backyard, or as large as the entire Chesapeake Bay watershed.

The Bay Ecosystem

The Chesapeake Bay, the largest estuary in the United States, is an extremely productive and complex ecosystem. The Bay ecosystem consists of the Bay itself, its local rivers and streams, and all the plants and animals it supports. Learn more about the Chesapeake Bay ecosystem.

Critter Of The Month

Morrow’s Honeysuckle
Lonicera morrowii

Morrow’s honeysuckle is an invasive shrub with white, tube-like flowers and small, bright red and orange berries.

Chesapeake History


  • The Chesapeake Executive Council signs the Chesapeake Bay Watershed Agreement, which contains goals and outcomes that will guide conservation and restoration across the watershed. For the first time, the Bay’s headwater states commit to those goals that reach beyond water quality.


  • A federal judge rules that the U.S. Environmental Protection Agency can set pollution limits for the Chesapeake Bay, thus upholding the Total Maximum Daily Load (TMDL) that was challenged in court in 2011.


  • Harris Creek becomes the first target of the oyster restoration goals set forth in the Chesapeake Bay Executive Order: to restore oyster populations in 20 Bay tributaries by 2025. In this Choptank River tributary, existing reefs will be studied, new bars will be built and spat-on-shell will be planted.


  • The U.S. Environmental Protection Agency issues a new Municipal Separate Storm Sewer Permit to the District of Columbia. It is the first of its kind to incorporate green infrastructure into its requirements, setting a national model for stormwater management.


  • Maryland, Virginia and New York ban phosphates in dishwasher detergent to lower phosphorous pollution in local waterways.
  • The U.S. Environmental Protection Agency establishes the Total Maximum Daily Load to limit the amount of pollutants that can enter the Chesapeake Bay.
  • The Bay Program launches ChesapeakeStat to improve communication about restoration goals, progress and funding.


Do phytoplankton migrate?

How does temperature affect the growth of underwater grasses?

How do animals depend on underwater grasses?

How rapid is sea level rising in the Chesapeake Bay?

How can people save underwater grasses?

Are American shad endangered?

What is a tributary?

How do you measure salinity?

Why does the Chesapeake Bay need plankton?

How does oxygen get into the water?

See more FAQs.

Bay Glossary


An organism that will eat both plants and animals.

Dead zone

A condition where no oxygen is present in the water. Dead zones are often caused by the decomposition of algae blooms.


A plant or animal that has both male and female reproductive organs and secondary sexual characteristics.


The thickness, opaqueness or reduced clarity of water caused by the suspension of sediments. The turbidity of rivers and streams increases after a rainfall.

Food chain/web

A food chain is formed as one organism eats another. A food web is a system of interlocking and interdependent food chains, in which each organism supplies energy to another life form.

Water quality criteria

Water quality conditions necessary to protect aquatic plants and animals.

Total maximum daily load (TMDL)

Defines the pollutant load that a water body can acquire without violating water quality standards, and allocates the pollutant loading between contributing point sources and non-point sources.


The male reproductive organ of a flower.

See more bay terms.

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