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 2010 sampling sites.

In 2010, benthic community condition declined throughout the mainstem of the Bay and its tributaries, except for the James River. Forty-seven percent of the Bay’s tidal waters in 2010 met the Restoration Goal, compared to 56% in 2009.

The largest increase in percent degraded area was in the Maryland upper western tributaries. The Maryland upper western tributaries, Maryland mid-Bay mainstem, Patuxent River, and Rappahannock River were in the poorest condition. The increased degradation observed in Chesapeake Bay in 2010 coincided with high river flows, which bring increased nutrients and sediment loads into Chesapeake Bay.

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