Friends of Dyke Marsh is a volunteer group dedicated to preserving, restoring and enhancing Dyke Marsh, a freshwater tidal marsh in Fairfax County on the Potomac River just south of Alexandria, Virginia. The Dyke Marsh Wildlife Preserve is administered by the National Park Service.

What Is Dyke Marsh?

The Dyke Marsh Wildlife Preserve is a freshwater, tidal marsh on the Virginia side of the Potomac River in Fairfax County. It is a unit of the George Washington Memorial Parkway, U.S. National Park Service. For more information, visit the NPS website at

Ospreys Have Returned, Aerial Combat Begins


The week of March 11, 2019, ospreys (Pandion haliaetus) returned to the Potomac River and Dyke Marsh.  As documented by our excellent photographer and observer, Ed Eder, it did not take long for fights to break out over fish, with a second-year bald eagle (Haliaeetus leucocephalus) causing an osprey to drop its catch. Later, the osprey sought revenge by dive-bombing the eagle.

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People Care

Notre Dame

In contrast to many who apparently don’t care about trashing our natural resources, as evidenced by the endless trash along the shoreline and in the marsh, many people do care.  On March 16, 25 members and young members-to-be of the Notre Dame Club of Washington, D.C., helped clean up trash along the west side of the George Washington Memorial Parkway north of Dyke Marsh. 

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The Importance of Vernal Pools

Eastern Spadefoot

Karen Sheffield explored the characteristics and importance of vernal pools to a rapt audience of 60 on March 3, 2019 at a meeting sponsored by the Friends of Dyke Marsh, Friends of Huntley Meadows Park, Friends of Mason Neck State Park and Friends of Accotink Creek.  Ms. Sheffield is the manager of Huntley Meadows Park and Historic Huntley, Fairfax County Park Authority, and oversees a survey of vernal pools there.

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Connecting to the Larger Community

FODM table

On February 2, 2019, the Friends of Dyke Marsh again participated in Mount Vernon Supervisor Dan Storck's annual town meeting at Mount Vernon High School, at which Supervisor Storck and other officials reviewed his accomplishments and challenges facing the community.  FODM had a table and materials in the exhibit hall alongside other friends’ groups. FODM volunteers greeted visitors and informed them about Dyke Marsh, the restoration project and FODM’s activities and goals.

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Restoration Work Advances


In early January 2019, the Dyke Marsh restoration breakwater became more and more visible as crews from Coastal Design and Construction continued to install 50 to 55 “marine mattresses” each working day.  By January 8, they had placed 2,900 in the south marsh.  On January 9, crews on a work barge and a rock barge began putting armor stone on top of the mattresses near the shoreline.  A surveyor on the shoreline monitors the tide level and helps ensure that the mattresses are placed at the right elevation.

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The Government Shutdown: Bird Walks Continue; Report Harm


During the current federal government closure, as of January 2, 2019, people can access the Dyke Marsh Wildlife Preserve trail and our Sunday, 8 a.m., bird walks are allowed.  Therefore, the walks will resume on January 6.   All restrooms are closed.

The National Park Service website ( says that “for most parks, there will be no National Park Service-provided visitor services, such as restrooms, trash collection or facilities or road maintenance.”

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Students Explore Dyke Marsh


On November 8, 2018, 37 enthusiastic fourth graders from the Arlington’s Randolph Elementary School explored the Dyke Marsh Wildlife Preserve with National Park Service staffers Brent O'Neill, Miguel Roberson and Susan Chumley, along with FODM volunteers.

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The GW Memorial Parkway's Rich Biodiversity

Brent Steury

On November 14, 2018, Brent Steury, Natural Resources Manager for the George Washington Memorial Parkway, told 65 FODMers and friends that the parkway is rich and biodiverse in its natural resources in a presentation describing the Parkway’s all-taxa inventory.  The Parkway is a national park of which the Dyke Marsh Wildlife Preserve is a unit.

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Dyke Marsh West

Dyke Marsh west

Around 15 to 20 acres of Dyke Marsh stretch west of the George Washington Memorial Parkway behind the Belle Haven and River Towers Condominiums. This part of the marsh can be seen from the parkway and the condos, but it is not easily accessible to the public.  Several FODMers regularly observe this part of Dyke Marsh. 

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FODMers Participated in the Environment Expo


The Friends of Dyke Marsh exhibited at Fairfax County Board of Supervisors’ Mount Vernon Supervisor Dan Storck’s Environment Expo on November 10, 2018, an event which Supervisor Storck hopes to hold again.  Over 130 people attended and were inspired to become better environmental stewards in eight workshops and in watching the movie “Hometown Habitat.”

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Breakwater’s Base Being Built


In mid-October 2018, crews from Coastal Design and Construction continue to build a breakwater in Dyke Marsh to help stop erosion and encourage sedimentation, the first stage of marsh restoration.  As of October 17, 2:30 p.m., the team had installed three layers of “marine mattresses” or 1,624 units.  The total final number will depend on the depth of the river bottom.  A new barge load will arrive soon.  

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Planting Again to Restore Habitat with Native Plants


On October 4, 2018, ten dedicated FODM volunteers and National Park Service staffers put in another 400 or so plants in our native plant demonstration area along the west side of the Haul Road trail, bringing our total plantings this year to around 3,500.   Despite the oppressive heat and a “healthy population” of mosquitoes, “It was a true labor of love,” said Ned Stone, FODM Vice President. 

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