| 
Benthic Index of Biotic IntegrityThe Benthic Index of Biotic Integrity (BIBI) measures the condition of the benthic community (e.g. clams and others) living in or on the soft bottom areas of the Bay. These organisms are a key food source for many species including perch, spot, and croaker.
Indicator Details:
Threshold Map
Editable Vector Version (SVG)
High Resolution Raster Version (JPG)
Samples for assessing benthic community (bottom habitat) were collected at approximately 300 sites in August and September 2007 by the Chesapeake Bay Benthic Monitoring Program. Data from each sampling station is used to calculate a Benthic Index of Biotic Integrity (BIBI) score. The proportion of the reporting regions area meeting the benthic index of biological integrity score is calculated and mapped.
Data Map
Editable Vector Version (SVG) High Resolution Raster Version (JPG)
This map shows the Benthic Index of Biotic Integrity (Benthic IBI) values for the summer of 2007. This Benthic IBI evaluates the health of the benthic community (soft-bottom only). Values between 1 and 3 are considered to be degraded relative to reference communities, while values between 3 and 5 are considered to be close to reference community condition. Stations with relatively good benthic community health tended to be located in the mainstem Bay, Lower Eastern Shore (Tangier), and in the vicinity of the Upper Western Shore and Patapsco and Back Regions. Areas with a concentration of poor Benthic IBI scores can be seen at the mouth of the Potomac and Rappahannock Rivers.
Samples for assessing the Benthic Index of Biotic Integrity (soft bottom community condition) were collected at approximately 300 sites in August and September 2007. Data from each sampling station is used to calculate a Benthic IBI score which ranges from 1 (poor benthic condition) to 5 (good benthic condition).
Ranking
| Score (%) | |
| 0 20 40 60 80 100 |
| Patapsco and Back Rivers | |
| Upper Western Shore | |
| Upper Bay | |
| Lower Bay | |
| Choptank River | |
| Overall Bay | |
| James River | |
| Lower Eastern Shore (Tangier) | |
| Patuxent River | |
| Potomac River | |
| York River | |
| Upper Eastern Shore | |
| Rappahannock River | |
| Mid Bay | |
| Lower Western Shore (MD) | |
| Elizabeth River | Insufficient Data |
This figure ranks each region from best to worst for the indicator Benthic Index of Biotic Integrity (Benthic IBI). The Benthic IBI evaluates the health of the benthic community (soft-bottom only). The best Benthic IBI scores in 2007 were recorded in the Upper Bay, Upper Western Shore, and the Patapsco and Back Rivers Regions. The high Benthic IBI score recorded in the Patapsco and Back Rivers region may in part be due to fewer sampling stations compared to previous years. Four regions had poor overall Benthic IBI scores. Benthic IBI scores increased in 7 regions in 2007 compared to 2006 and decreased in 7. It is not possible to provide a score for the Elizabeth River Region until monitoring data becomes available later in the year.
Excel SpreadsheetTrends Graph
This graph is dynamic, you can check and uncheck regions (
checkboxes in legend), select year range (
click and drag), and export as an image (right click).
Editable Vector Version (SVG) Excel Spreadsheet