How's the Bay Doing?

Benthic community condition in Chesapeake Bay is assessed using a benthic index of biotic integrity (B-IBI), which evaluates the ecological condition of a sample by comparing values of key benthic community attributes to reference values expected under non-degraded conditions in similar habitat types. Probability-based sampling and the B-IBI are used to estimate the area of Chesapeake Bay with degraded bottom habitat condition.

Click here to see a map of the bottom habitat condition for each of the 2011 sampling sites.

Benthic community condition in 2011 declined in the Potomac, York, and James rivers, but other regions of the Bay showed improved condition or no change. Overall, benthic community condition was similar in 2011 and 2010. Forty-five percent of the Bay’s tidal waters in 2011 met the Restoration Goals compared to 47% in 2010.

Benthic condition improved in the Maryland portion of the Bay (except in the Potomac River), suggesting no immediate effects of Tropical Storm Lee at sites sampled 1 to 14 days after the storm. Improvements were due to small increases in the abundance and numbers of species in Maryland tributaries and the main stem.

See results at right for further detail.

Patterns of condition within each stratum can be explored from the interactive stratum map below. 

Click on the stratum name or area for detailed results

      Summary of Results

      Baywide Results Graph

      Sampling Strata

      Areas Failing Goals

      Fixed Station Trends

   Recent Research Results

Low dissolved oxygen and benthic production