Friends of Dyke Marsh - Friends of Dyke Marsh

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 www.nps.gov/gwmp.

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FODM 2025 Membership Meetings

Researchers here Matt Ashton lower cages into the river. The cages contain fish carrying microscopic mussel larvae 175

February 23, in-person, Mount Vernon Government Center

2 to 3 p.m., social hour; 3 p.m. speaker

Dean Naujoks, Potomac Riverkeeper, will describe efforts to bring mussels back to the Potomac River.

Sponsors: Friends of Dyke Marsh; Friends of Mason Neck State Park; Northern Virginia Chapter of Trout Unlimited; Four Mile Run Conservatory Foundation; Friends of Little Hunting Creek; Prince William Conservation Alliance

May 14, 7 p.m., on Zoom

October 22, 7 p.m., on Zoom

Check back for topics and speakers.

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October 23, 2024 7 p.m., Zoom
Dr. Rebecca Forkner, Associate Professor, George Mason University, discussed caterpillars.

Click here to view a video of this presentation.

Join / Renew

Coming Events

Help Tackle Invasive Plants

Nancy Herman Nancy Herrman is a dedicated invasive plant volunteer.

Join FODMers from 10 a.m. to noon on:

January 4 and 18
February 1 and 15
March 1, 15 and 29

Help protect native plants by pulling and clipping invasive plants. We will train volunteers to identify the five or so target plants. Click here to register to join us in any of these sessions. We kindly ask that you not bring pets. Invasive plants can threaten and outcompete native plants.

Bring gloves, hand clippers and water. We will supply instructions, examples and trash bags. Wear long sleeves and pants and sun protection. We will have some tools to share. We will cancel if lightning or severe storms are anticipated.

Meet at the Haul Road trail entrance bench.

For sessions beginning at 10 a.m., if it is raining at or after 9 a.m. on the day of the session, the session will be cancelled.

Help Clean Up Trash, January 18

Join your friends in a trash cleanup in Dyke Marsh and along the Potomac River shoreline, Saturday, January 18, 9 a.m. to 11 a.m. Check in at Belle Haven Park or the Dyke Marsh Haul Road entrance. Sponsors will provide gloves, bags and tools.

Wear sturdy shoes, warm clothing, long pants and sleeves and layers. Some areas could be muddy. Bring water in a reusable bottle.

This event will occur unless there are heavy rains and/or lightning and NPS will notify you of a cancellation. This is the annual Martin Luther King Day of Service, but since the official day conflicts with the inauguration, we are holding it on January 18.

Sponsors: Friends of Dyke Marsh (www.fodm.org) and the National Park Service/George Washington Memorial Parkway (www.nps.gov/gwmp)

Please register here.

Haul Road Trail directions and parking: GPS coordinates: 38.777739, -77.050540 South of Alexandria off the GW Memorial Parkway at the sign for Dyke Marsh Nature Preserve and Belle Haven Marina, turn east onto the road toward the Potomac River. Take the first left and park in the Belle Haven Park lot. Walk back to the marina road and turn east, toward the river. Walk 30 yards. On your right is a Dyke Marsh sign and the entrance to the Haul Road trail.

Spotted Lanternfly Alert

Spotted lanternfly
(Lycorma delicatula)
Photo by NPS

The National Park Service (NPS) asks that everyone be on the lookout for an invasive insect called the spotted lanternfly (Lycorma delicatula). As of February 3, 2023, there have been no reports of these insects on the GW Memorial Parkway properties, but the insect has been documented in Fairfax County. Please be on the lookout for their egg masses on trees and other smooth surfaces (including rocks and vehicles) from now through spring. Egg masses look like smears of mud or mortar. NPS asks that if you see one, try to scrape it off and put it into a baggie with some rubbing alcohol or hand sanitizer.

The insect can be very destructive to trees.

There is more information in an article by a NPS official here.

For information in another article by the US Department of Agriculture click here.

Help Stop the Spread of a New Species of Water Chestnut

Water chestnut. Photo from MISC, Maryland Invasive Species Council.

Be on the lookout for a new species of water chestnut (genus Trapa) (http://mdinvasives.org / iotm/june-2018/) found in the Potomac watershed, Trapa bispinosa Roxb. var. iinumai Nakano. It has been spreading since 1995 and is floating aquatic vegetation growing over the surface of a pond, lake or other fresh waterbody.

This species is identified by the seed cases having two spines instead of four found on Trapa natans. Report all invasive aquatic species to the US Geological Survey’s Nonindigenous aquatic species website (https://nas.er.usgs.gov / SightingReport.aspx).

Water chestnut (an annual) sprouts in May, spreads over the water surface and then flowers and fruits by July. It drops seeds all season until it senesces after a hard frost. To stop the spread, management by harvesting the plants by early July is very successful in eradicating the plants, but it may take several years of effort, if some seeds fall before the plants are harvested or lay dormant in the current year and sprout in a later year.

Sunday Bird Walks

bird walks

FODM hosts bird walks every Sunday at 8 a.m. Meet in the Belle Haven Park south parking lot. We will cancel walks if weather conditions are unsafe, such as lightning, ice or heavy rain or snow.

So members can participate in the annual Christmas Bird Count, FODM will not hold bird walks between December 14, 2024, and January 5, 2025.

Parking Alert

The U.S. Park Police are now ticketing vehicles parked on either side of the Marina Road. While the signage may be confusing, an officer on May 6, 2023, told us that except for the two marked handicapped parking spots near the Mount Vernon Trail, only vehicles with attached trailers can park on the sides of the Marina Road.

Support FODM

Your contribution will help us preserve and restore Dyke Marsh and support special programs and studies. Thank you.

Donate

Like Us on Facebook!

FODM is on Facebook. If you are already a Facebook member, just log in to your Facebook page and search for "Friends of Dyke Marsh". Or, click this icon and then "like" us:

Marsh Viewer

dyke marsh past and present 225

These aerial photos of Dyke Marsh are from a Fairfax County imagery viewer and were taken in 1937 (left) and 2021 (right) and show how much of the wetland habitat has disappeared (See our restoration page). To view these photos in a larger format and to learn more about using the imagery viewer, click here.

Bienvenidos!

Dyke Marsh

The Friends of Dyke Marsh extend a welcome to all of our friends. Click here for an invitation to the Dyke Marsh Wildlife Preserve in Spanish, which we hope will make Spanish-speaking visitors feel welcome. We hope to see you soon.

Click here for a flyer for Spanish-speaking children, what they can see in Dyke Marsh.

The Potomac River

Paddling

FODM President Glenda Booth wrote this article about the Potomac Conservancy’s 2023 Potomac River report card, “The Potomac River: Progress Yet Problems.” It was in the May 31, 2023, Connection newspapers.

See the article here.

Northern Virginia's Butterflies

Dyke Marsh

FODM President Glenda Booth wrote an article titled "Documenting Butterflies" about the 2022 Northern Virginia butterfly survey, led by Larry Meade. It was published in the October 6 Mount Vernon Gazette/Connection Newspapers. Dyke Marsh was one of the sites surveyed and several FODMers participated.

See the article here.

On the Potomac River

Wintering Waterfowl

Tundra swan (Cygnus columbianus) Photo by Cathy Ledec.

FODM President Glenda Booth has an article in the January 2020 Zebra newspaper on waterfowl on the Potomac River in winter. Read the article here.

Peregrine Falcons

Peregrine falcon over the Potomac River near the Wilson Bridge. Photo by Ed Eder

FODM President Glenda Booth published an article in the September 24, 2020 Ashburn Magazine titled “Peregrine Falcons Choose Ashburn Quarry to Raise their Young.” To read the article, click here.

"On the Edge," a Film about Dyke Marsh

Dyke Marsh

“On the Edge – the Potomac River Dyke Marsh” is a 43-minute video commissioned by the Friends of the Dyke Marsh in 2005 which premiered at the Kennedy Center to a capacity crowd. The video features the biodiversity of Dyke Marsh and many of the people who have been instrumental in preserving it. Dave Eckert was the videographer and producer. You can view the video online here.

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