Restoring Underwater Bay Grasses

The Chesapeake Bay Program is currently working towards a goal to restore underwater bay grasses — also known as submerged aquatic vegetation or SAV — to 185,000 acres in the Bay and its tidal tributaries by 2010.

Better science allows researchers today to target restoration efforts in areas where bay grasses once grew. However, the Bay's continuing poor health, along with a lack of funding and irregular weather conditions, have hindered progress toward reaching the 185,000-acre bay grass goal.

Strategy to Protect and Restore Underwater Bay Grasses

In 2003, the Chesapeake Bay Program adopted the Strategy to Accelerate the Protection and Restoration of Submerged Aquatic Vegetation in the Chesapeake Bay, which set a goal of having 185,000 acres of bay grasses by 2010.

To reach this goal, the Bay Program outlined four initiatives that must be implemented for bay grass restoration to be successful:

Improve Water Clarity

Sunlight is the single most important factor determining the growth and survival of underwater bay grasses. Therefore, improving water clarity is a major component of bay grass restoration.

Maryland, Virginia and the District of Columbia have specific criteria for water clarity in shallow waters where bay grasses exist or once grew. The criteria, which apply to water depths of up to 2 meters, list exact percentages of sunlight that must be able to penetrate through the water.

• In low-salinity waters, 13 percent of the light that hits the water’s surface must reach underwater bay grasses at the bottom.
• In high-salinity waters, 22 percent of the light that hits the water’s surface must reach underwater bay grasses at the bottom.

Meeting these water clarity guidelines is critical to helping new bay grasses grow and allowing existing bay grass beds to expand.

Increase Protection of Existing Bay Grass Beds

Increase protection of existing bay grass beds from invasive species and human activities.

Plant 1,000 Acres of Bay Grasses

To help accelerate progress toward the 185,000-acre goal, the Bay Program set an additional goal to plant 1,000 acres of underwater bay grasses by the end of 2008. Planting bay grasses supplements the natural expansion of grass beds that comes with protection and pollution reductions. As of 2008, Bay Program partners had planted 148 acres of bay grasses, achieving just 15 percent of the goal.

The Maryland Department of Natural Resources, a Bay Program partner, led a large-scale eelgrass restoration project on the Patuxent and Potomac rivers between 2004 and 2008. In a 2009 report on the restoration project, DNR concluded that using seeds is a practical way to restore eelgrass in the Bay and outlined the costs and effectiveness of various methods of collecting and planting eelgrass seeds.

Enhance Bay Grass Research, Education and Outreach

Types of Underwater Bay Grass Restoration

Many different organizations — ranging from federal and state agencies to local and volunteer-based groups — are leading projects to restore and protect underwater bay grasses and educate citizens about their importance.

• State Bay Program partners monitor and protect grass beds in critical areas.
• Many local residents assist small watershed organizations with harvesting, growing and planting bay grasses on a smaller scale.
• School-aged children are planting, growing and studying bay grasses through Bay Grasses in Classes, a program run by the Chesapeake Bay Foundation and the Maryland Department of Natural Resources.
• The Chesapeake Club media campaign uses humor to educate homeowners about the impact of lawn fertilizers on water quality, bay grasses and blue crabs.

In addition to these projects, tributary strategies—clean-up plans for each tributary in the watershed—contribute to SAV restoration efforts by reducing nutrient and sediment pollution to the Bay.