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Browse History: Bay Health Index (2007)
Indicator Icon Bay Health Index

The Bay Health Index is an average of all seven indicators (chlorophyll a, dissolved oxygen, water clarity, total nitrogen, total phosphorus, aquatic grasses, and Benthic IBI) into an overall assessment of Chesapeake Bay health.

Chesapeake Bay - Indicator Details:





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Index Map

This map shows the 2007 Bay Health Index scores for each of the 15 regions. These scores are used to provide report card grades (A to F) for each of the regions. Most regions of the Bay fell into one of two health grades; poor or moderate, with the exception of the Upper Western Shore, which had a moderate–good score. Bay Health Index scores increased in 8 regions in 2007 compared to 2006 and decreased in 6 (incomplete monitoring data available for the Elizabeth River).

Creating this map
This map shows the 2007 Bay Health Index scores for each the 15 reporting regions. The Bay Health Index for each reporting region is the average of the Water Quality Index and the Biotic Index scores.

Ranking


Comparison of Bay Health Index scores for 2007 () compared to
()


Score Legend
 Score (%)
 0               20               40               60               80              100
  
Upper Western Shore  
Upper Bay  
Lower Bay  
James River  
Overall Bay  
Choptank River  
Potomac River  
Mid Bay  
Rappahannock River  
Lower Eastern Shore (Tangier)  
Upper Eastern Shore  
Patapsco and Back Rivers  
York River  
Elizabeth River  
Lower Western Shore (MD)  
Patuxent River  

This figure ranks each region from best to worst for the Bay Health Index scores for 2007. The Upper Western Shore and Upper Bay Regions had the highest score because of the high Water Quality Index and Biotic Index scores. Most regions received a poor Bay Health Index score, with the exception of the Upper Bay, James River, and Lower Bay regions which scored a moderate rating. Bay Heath Index scores increased in 8 regions in 2007 compared to 2006 and decreased in 6, (incomplete monitoring data available for the Elizabeth River).


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