The deepest part of the Chesapeake Bay is 174 feet deep. It is located off Bloody Point, southeast of Annapolis. The average depth of the Bay, including tributaries, is about 21 feet.

However, most of the Bay measures less than six feet deep!

Because the Bay is so shallow, its water temperature fluctuates widely throughout the year, ranging from 34 to 84 degrees Fahrenheit. Changes in water temperature influence the growth of underwater grasses and when fish, crabs and other animals feed, reproduce or migrate to other areas.

As you go deeper into the Bay, “pelagic”, or free swimming species, such as fish become less common.

The deepest parts of the bay are probably populated by the benthos; a community of organisms that live on the bottom of the Bay and its tributaries. This “benthic” or bottom-dwelling community is made up of primarily of marine worms, isopods and tiny snails. These important creatures serve as excellent biological indicators. They are reliable and sensitive gauges of habitat quality in the Bay and are an important part of the Chesapeake Bay’s food web.

- Mark Lewandowski
Natural Resources Biologist
Tidewater Ecosystem Assessment Division
Maryland Department of Natural Resources