Benthic Community

Chesapeake Bay

The Benthic Index of Biotic Integrity (BIBI) measures the condition of the benthic community (e.g. clams and others) living in or on the soft bottom areas of the Bay. These organisms are a key food source for many species including perch, spot, and croaker.

Chesapeake Watershed

Stream benthic community measures the condition of the benthic community living in streams. Benthic macroinvertebrates are freshwater organisms including snails, mussels, worms, and insects that live in and on the stream and river bottom. These organisms are a key food source for many fish species.

Tube worms (seen on this brick) are a type of polychaete that is part of the benthic community. Other organisms are clams, amphipods, polychaetes, and isopods.

How is it measured?

Chesapeake Bay

Samples for assessing benthic community (bottom habitat) were collected at approximately 250 sites in July, August, and September by the Chesapeake Bay Benthic Monitoring Program. Data from each sampling station is used to calculate a Benthic Index of Biotic Integrity (BIBI) score. The proportion of the reporting regions area meeting the Benthic Index of Biological Integrity score is calculated and mapped.

Chesapeake Watershed

Samples for assessing benthic community (bottom habitat) were collected from 2006-2011.  Data from each sampling station is used to calculate a Benthic Index of Biotic Integrity (BIBI) score. The stations are averaged to the HUC12 level. The proportion of the HUC12s area meeting the Benthic Index of Biological Integrity score is calculated. These scores are area-weighted to the region scores.