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185,000 acres by 2010.

• Aside from the water itself, underwater bay grasses are one of the most important habitats in the Chesapeake Bay. As their health is closely related to the quality of local waters, grasses serve as an excellent barometer for the overall health of the estuary. Bay grass abundance has a profound effect on the Bay and its aquatic life, as it provides critical habitat to key species such as striped bass and blue crabs while improving the clarity of local waters.
• The total Bay grass abundance goal has also been broken down by three zones. Bay grasses in the Upper Bay in 2007 covered about 19,000 acres or 80 percent of the 23,630-acre goal. For 2007, Middle Bay grasses covered roughly 30,000 acres or 26 percent of the 115,229-acre goal, while grasses in the Lower Bay covered 16,000 acres or 35 percent of the 46,030-acre goal.
• As water clarity improves from nutrient and sediment pollution reductions, bay grass acreage should expand.
• Bay grasses, or submerged aquatic vegetation (SAV), are important to the complex Chesapeake Bay ecosystem because they produce oxygen, supply food for many species (especially waterfowl), offer shelter and nursery habitat for fish and shellfish, reduce wave action and shoreline erosion, absorb excess nutrients such as nitrogen and phosphorus, and trap sediments.
• Review of photographic evidence from a number of sites dating back to 1937 suggests that close to 200,000 acres of SAV may have historically grown along the shoreline of the Bay. However, by 1984, the SAV community had fallen to a low of about 38,000 acres. Increasing quantities of nutrients, such as phosphorus and nitrogen, as well sediment in the water have choked or eliminated the growth of SAV in many areas, and contributed to declines in SAV acreage throughout the Bay.
• Bay grasses are a unique yardstick for measuring the progress of Chesapeake Bay restoration efforts because they are not under harvest pressure and their health is closely linked to water quality. Increases in Bay grasses are expected in areas where water quality conditions are improving.
• In 1993 the Chesapeake Bay Program (CBP) agreed to work to restore SAV to its historical levels. They set an interim restoration goal of 114,000 acres - the total area vegetated at one time or another since the early 1970s. Based on rates of recovery at that time, the goal was expected to be achieved by 2005.
• In the Chesapeake 2000 agreement, the CBP recommitted to the existing goal of protecting and restoring 114,000 acres of SAV. They also agreed to “revise SAV restoration goals and strategies to reflect historic abundance, measured as acreage and density from the 1930s to the present. The revised goals will include specific levels of water clarity which are to be met in 2010. Strategies to achieve these goals will address water clarity, water quality, and bottom disturbance.”
• In 2003, the CBP adopted the Strategy to Accelerate the Protection and Restoration of Submerged Aquatic Vegetation in the Chesapeake Bay including a new Baywide restoration goal of 185,000 acres by 2010. This acreage represents approximate historic abundance from the 1930s to present. Scientists believe increasing bay grass coverage beyond today's acreages will result in dramatic improvements throughout the entire Bay ecosystem.
• The aerial survey is flown from late spring to early fall. The photography is processed in the fall and winter, and preliminary area totals are usually available the following spring. For additional information about the aerial survey and for segment specific survey results, go to www.vims.edu/bio/sav/

• Bay Grass Abundance (Upper, Middle and Lower Bay Zones)
• Bay Grass Density

For more information contact: Jennifer Greiner at 800-968-7229 ext. 783

Virginia Institute of Marine Science