Maps

This map shows the percent of the Index of Biological Integrity indicator goal achieved by segment.

This map shows the 2010 indicator status of the Benthic Index of Biological Integrity by station.

This map shows the 2009 indicator status of the Benthic Index of Biological Integrity by station.

This map shows the percent of the Index of Biological Integrity indicator goal achieved by segment.

This map shows the 2008 indicator status of the Benthic Index of Biological Integrity by station.

This map shows the percent of the Index of Biological Integrity indicator goal achieved by segment.

This map shows the Percent of the Index of Biological Integrity Indicator Goal achieved by segment.

This map shows the 2007 Indicator Status of the Benthic Index of Biological Integrity by station.

Each state in the watershed conducts benthic macroinvertebrate assessments as part of its biennial water quality assessment report mandated by the Clean Water Act. Where assessed benthic macroinvertebrate communities are deemed the most degraded, states must designate those stream segments as impaired and add them to the list of impaired waters in need of cleanup. The Bay Program state partners - Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia - used the data and results from their 2006 water quality assessments to prepare summaries of stream conditions in each state. The methodologies for benthic macroinvertebrate assessment vary by state, therefore a synthesis of results across the entire watershed was not attempted at this time The map presents a summary of each state's assessment results within the boundaries of the Chesapeake Bay watershed.

Benthic organisms are animals, plants and bacteria that live on or at the bottom of water bodies. These benthos are an important part of the food web, as they consume phytoplankton and in turn are consumed by larger organisms, including finfish. Another service benthic organisms perform is to break down organic matter that collects on the bottom of the Bay. The Chesapeake Bay Program monitors the health of these benthic communities using both fixed and random stations. The results of this monitoring are compiled into an Index of Biotic Integrity (IBI).