Maryland Department of NATURAL RESOURCES

The Chesapeake Bay

Facts about the Chesapeake Bay and Watershed

A boy on a boat holding a blue crab and smiling.
  • Illustration of a blue crab.The Bay is an estuary, a body of water where fresh and saltwater mix. The Bay is surprisingly shallow—the average depth is about 21 ft. It is 200 miles long and varies in width from 3.4 miles to 35 miles at the mouth of the Potomac River.

  • Illustration of a blue crab.The Bay supports more than 36,000 species of plants, fish and animals, including 348 species of fish, 173 species of shellfish and over 2,700 plant species.

  • Illustration of a blue crab.The Bay receives about half its water from the Atlantic Ocean. The rest drains into the Bay from its very large 64,000 sq. mile watershed, composed of parts of six states.

  • Illustration of a blue crab.Everyone in the Watershed lives just a few minutes from one of the more than 100,000 streams and rivers that drain into the Bay. Each of these streams can be considered a pipeline from communities to the Bay.

  • Illustration of a blue crab.To restore the Bay, everyone has to make changes in the way we live in our communities, homes, yards, and schools. 

Links to help you with more Bay information…

  • Chesapeake and Coastal Bay Life Guide - guide to organisms found in and around the the bay
  • Estuaries - general information about estuaries, available data, ways to get involved and other resources
  • Eyes on the Bay - access real-time Chesapeake and Coastal Bays water quality monitoring data
  • Chesapeake Bay National Research Reserve - (CBNERR) offers hands-on outdoor science learning with strong focus on wetlands, forests, and bay watershed for pre k-12 students and the public. Join us at Jug Bay Wetlands Sanctuary, Anita C. Leight Estuary Center, Patuxent River Park, and Monie Bay (programs provided upon request).
  • ​ Chesapeake Bay Program - a regional partnership that leads and directs Chesapeake Bay restoration and protection. FAQs about bay and watershed.
  • Chesapeake Bay Monitoring Program - measures key components of the ecosystem, including pollutant inputs, water quality, habitat and living resources.