Aquatic 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:
Estimates of aquatic grasses cover are derived each year 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 color representing progress towards the goal.
This map shows the preliminary aquatic grasses (submerged aquatic vegetation) distribution in 2007. 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 cover in many other areas. During 2007, many areas of the Bay, such as the Upper Bay and Upper Western Shore regions, experienced a significant increase in aquatic grasses area compared to 2006. There were also many regions recording a decline in aquatic grasses area such as the Patapsco and Back Rivers, Patuxent River and Lower Western Shore (MD) regions.
Estimates of aquatic grasses cover are derived each year using aerial surveys. Survey data was used to determine area of aquatic grass in each reporting region for 2006 and 2007. Percent (%) difference in area between 2006 and 2007 was calculated.
Comparison of Bay Health Index scores for 2007 () compared to ()
|0 20 40 60 80 100|
|Upper Western Shore|
|Lower Eastern Shore (Tangier)|
|Lower Western Shore (MD)|
|Upper Eastern Shore|
|Patapsco and Back Rivers|
No Growth Zone
This figure ranks each region from best to worst for aquatic grasses scores in 2007. 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. The Upper Western Shore and Upper Bay regions are closest to the restoration goal. Aquatic grasses in the Upper Bay region have been expanding in recent years. The Patapsco and Back Rivers region had the lowest score in 2007, mostly due to loss of aquatic grasses in the upper reaches. Overall, most regions are far from achieving their restoration goals.
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.
|Reporting Region||SAV restoration goal by reporting region (acres)|
|Elizabeth River||No Grow Zone|
|Upper Eastern Shore||12,866|
|Lower Eastern Shore (Tangier)||57,651|
|Upper Western Shore||3,661|
|Lower Western Shore (MD)||1,811|