Benthic animals, such as these
polychaetes, live in or on the bottom

The benthos is the community of organisms that live in or on the bottom of the Bay and its tributaries.  Examples of some benthic animals that live in Chesapeake Bay sediments include clams, amphipods, polychaetes (bristle worms), and isopods. Benthic macroinvertebrates are used as biological indicators because they are reliable and sensitive indicators of habitat quality in aquatic environments and they are ecologically important components of the Chesapeake Bay’s food web.

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The long-term benthic sampling program has two components. Probability samples are collected during the summer at 150 randomly-selected sites in 6 major regions of the Chesapeake Bay mainstem and tributaries in Maryland. Results from the probability sampling are used to determine the number of acres that meet the Chesapeake Bay Benthic Restoration Goals. These goals define a healthy benthic macroinvertebrate community. The second component of the program samples 27 fixed sites to see if management actions designed to improve water quality are resulting in healthier benthic communities.  Benthic community health serves as a measure of water quality that is integrated over time because it captures the effect of water quality problem such as low dissolved oxygen that occurred prior to the time of sampling.

For more information on the Maryland Chesapeake Bay Long-Term Benthic Monitoring and Assessment Program visit:

If you would like to learn more about the benthos community, please visit the Chesapeake Bay Life Guide.

For more information contact:
Renee Karrh
Tidewater Ecosystem Assessment
Maryland Department of Natural Resources
580 Taylor Avenue, D2
Annapolis, MD 21401

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