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In early June, the Maryland Department of Natural Resources (DNR), the Maryland Coastal Bays Program, the Virginia Institute of Marine Scientists, and the National Park Service released a study showing that underwater seagrass abundance in Maryland and Virginia's coastal bays increased by 25 percent last year. This increase, from 10,916 acres in 2008 to 13,628 acres in 2009, shows that the bays continue to recover from a dramatic loss suffered in 2005. The goal, developed by the Maryland Coastal Bay’s Scientific and Technical Advisory Committee, is 20,070 acres of seagrass – so, we’ve still got a long way to go.

Submerged aquatic vegetation, referred to as SAV, are plants, including eelgrass and widgeon grass, that grow under the surface in shallow water. SAV grows where light can penetrate the water – so, good water quality is essential. The presence, abundance, diversity, and health of SAV is one of the primary indicators of the health of our bays.

Grass is good! SAV provides critical food and shelter for fish and wildlife in our coastal bays, including blue crabs, shellfish, flounder, and seahorses, too. They are also an important source of food for migrating waterfowl. SAV helps remove harmful nutrient and sediment pollution from Maryland’s coastal waters. SAV stabilizes sediments and reduces wave energy and erosion of beaches and the shoreline. Underwater grasses filter polluted runoff and also uptake nitrogen and phosphorus that, in overabundance, lead to algal blooms that can impair water quality. Decomposing underwater grasses provide food for bottom-dwelling aquatic life.

Poor water quality is the biggest threat to seagrass recovery. Nutrient pollution fuels algae and seaweed blooms in the water which can block light to seagrass beds. Distribution of seagrasses in the northern bays is limited, presumably due to poorer water quality conditions.

Marylanders can take simple actions to help protect water quality in coastal bays and seagrasses.

The Coastal Bays Nutrient Reduction Action Strategy recommends common sense approaches to nutrient reductions, such as minimal use of lawn fertilizers; following recommended farming practices; avoiding seagrass beds when boating; and using good boating practices that keep pollutants out of the water.

Homeowners can have a particularly positive impact when they pump their septic tanks regularly, replace lawns with trees and native plants, build rain gardens, install rain barrels, diligently clean up pet waste and limit impervious surfaces on their property.

Increased nutrient inputs from point and non-point sources and sediments in the water

column decrease the amount of sunlight reaching seagrasses and are considered the

primary threat to seagrass health. Seagrasses in the Coastal Bays may also be damaged by

excessive macroalgae, brown tide, and recreational and commercial boating activity. Natural factors, such as sediment type and wave action, also influence the health and

location of seagrass beds.

"It’s good to see improvement in seagrass abundance; however, we have still not fully recovered from the losses suffered in 2005 when the bays lost 38 percent of the seagrass due to abnormally high water temperatures and poor water quality in some areas,” said Dave Wilson, executive director of the Maryland Coastal Bays Program. “The Coastal Bays Program will continue to work with local, state and federal partners as well as the farming and development communities to reduce nutrient and sediment pollution in order to reach our seagrass goal in the bays behind Ocean City and Assateague.”

For simple tips for boaters, homeowners, and visitors who want to help keep the seagrass growing, contact the Maryland Coastal Bays Program at mcbp@mdcoastalbays.org or visit www.mdcoastalbays.org for more information.