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Aquatic GrassesAquatic grasses, or submerged aquatic vegetation, are one of the most important habitats in Chesapeake Bay. Bay grasses provide critical habitat to key species such as blue crab and striped bass, and can improve water clarity.
Chesapeake Bay - Indicator Details:
Threshold Map
High Resolution Raster Version (PNG)
Station DataEstimates of aquatic grasses cover are derived each year by VIMS using aerial surveys. The aquatic grasses score is determined as the area of aquatic grasses present in each of the 15 reporting regions as a percentage of the restoration goal. Each reporting region is assigned a score representing progress towards the goal.
Data Map
This map shows the preliminary aquatic grass (submerged aquatic vegetation) distribution in 2010. While aquatic grasses fringe long sections of the shoreline, there are many areas of the Bay in which they no longer occur or have experienced a significant reduction in area. For example, aquatic grasses are absent in the Back, West, and Nanticoke Rivers and have very low coverage in many other areas. During 2010, aquatic grasses decreased slightly in many regions. However, the main areas with aquatic grasses, the Susquehanna Flats and Tangier Sound can be seen on this map. There were also slight increases in the Rappahannock River, the James River, and the York River, continuing the recovery of those areas. This assessment is based on aquatic grass survey data provided by VIMS. See http://www.vims.edu/bio/sav for more information.
Estimates of aquatic grasses cover are derived each year by VIMS using aerial surveys. Survey data was used to determine area of aquatic grass in each reporting region.
Ranking
Comparison of Bay Health Index scores for 2010 (
) compared to (
)
| Score (%) | |
| 0 20 40 60 80 100 |
| Upper Bay | |
| Rappahannock River | |
| Upper Western Shore | |
| James River | |
| Lower Bay | |
| Potomac River | |
| Overall Bay | |
| Lower Eastern Shore (Tangier) | |
| Upper Eastern Shore | |
| York River | |
| Mid Bay | |
| Patuxent River | |
| Lower Western Shore (MD) | |
| Choptank River | |
| Patapsco and Back Rivers | 0 |
| Elizabeth River | No Growth Zone |
This figure ranks each region from best to worst for aquatic grasses scores in 2010. The aquatic grasses score is determined as the area of aquatic grasses present as a percentage of the restoration goal. The Upper Bay and Rappahannock River regions are closest to the restoration goal; the Rappahannock River aquatic grasses have increased dramatically over the past seven years. The Upper Western Shore aquatic grasses declined by 10% this year. The Patapsco and Back River and the Choptank River regions continue to be the lowest scoring regions. Overall, most regions are far from achieving their restoration goals. This assessment is based on aquatic grass survey data provided by VIMS. See http://www.vims.edu/bio/sav for more information.
Excel SpreadsheetTrends Graph
This graph is dynamic, you can: a) show and hide items by clicking them in the legend, b) select year range (click and drag), and c) 
export as an image.
Excel SpreadsheetThreshold Levels
| Reporting Region | SAV restoration goal by reporting region (acres) |
| Upper Bay | 14,978 |
| Mid Bay | 18,436 |
| Lower Bay | 35,872 |
| Patuxent River | 1,954 |
| Potomac River | 21,203 |
| Rappahannock River | 2,534 |
| York River | 3,304 |
| James River | 2,629 |
| Elizabeth River | No Grow Zone |
| Upper Eastern Shore | 12,866 |
| Choptank River | 13,953 |
| Lower Eastern Shore (Tangier) | 57,651 |
| Patapsco-Back Rivers | 389 |
| Upper Western Shore | 3,661 |
| Lower Western Shore (MD) | 1,811 |
| Total | 191,241 |