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Browse History: Biotic Index (2010)
Indicator Icon Biotic Index

The Biotic Index combines the aquatic grasses, Benthic Index of Biotic Integrity, and Phytoplankton Index of Biotic Integrity into a single overarching score.

Chesapeake Bay - Indicator Details:





  Indicator Selection Diagram


Index Map

This map shows the 2010 Biotic Index scores for each of the 15 reporting regions. Highest Biotic Index scores occurred in the Upper Bay and Lower Bay regions. These regions were generally characterized by good benthic community scores. The lowest Biotic Index scores occurred in the Lower Western Shore (MD), Patapsco and Back Rivers, and Choptank River regions. Biotic Index scores increased in five regions in 2010 compared to 2009, decreased in eight, and remained steady in one. There is incomplete monitoring data available for the Elizabeth River, therefore it does not receive a Biotic Index score.

Creating this map
This map shows Biotic Index values for each of the regions. Biotic Index for each reporting region is the average of the aquatic grasses, Benthic Index of Biotic Integrity, and Phytoplankton Index of Biotic Integrity scores.

Ranking


Comparison of Bay Health Index scores for 2010 () compared to
()


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

This figure ranks each region from best to worst for the Biotic Index. Highest ranked region in 2010 was the Upper Bay, with a score of 62% (moderately good). Second highest ranked region, was the Lower Bay, at 60%. High Biotic Index Scores in these two regions are generally due to good benthic community scores. The Lower Western Shore (MD), Patapsco and Back Rivers, and Choptank River regions had the lowest Biotic Index scores in 2010, all scoring less than 20% (very poor). Biotic index scores increased in five regions in 2010 compared to 2007 and decreased in eight. There is incomplete monitoring data available for the Elizabeth River.


Excel Spreadsheet