Losing Wetlands

Lecture explains loss of acres of Dyke Marsh.

— National Park Service’s Matthew Virta described how, for hundreds of years, Dyke Marsh and its area residents lived in relative harmony until a single act triggered its rapid degradation.

Speaking at a Friends of Dyke Marsh quarterly meeting on Wednesday, Nov. 14, Virta, a cultural resources manager, described the authorized uncontrolled dredging and dumping in Dyke Marsh, without regard to the environmental consequences.

Virta presented his history research before an audience of approximately 90 attendees during the meeting held at the Huntley Meadows Park Visitor Center. During the presentation, Virta traced Dyke Marsh, a freshwater tidal wetlands, going back thousands of years based on archeological findings, to more recent early American history dating back 500 years ago and up to the present.

Glenda Booth, president of the Friends of Dyke Marsh, said, “Matthew Virta expertly outlined the rich human history of Dyke Marsh, from native Americans fishing and hunting, the railway from Washington to Mount Vernon, to bootlegging, hiding house boats that were thought to provide prostitution, and then in response to the destructive environmental impact of dredging, for the U.S. Congress to designate the protective stewardship that comes with becoming part of a national park.”

However, the erosion — begun because of years of dredging — continues unabated and restoration plans have to take place, and soon, according to the advocates and scientists who commented during the evening presentation. Through most of the Dyke Marsh history, Virta discussed how farmers, business people, residents, and others seeking recreational activities lived in relative harmony with the wetlands, and were able to benefit from its qualities as a source of food, farming, and recreation. It was not until the owners of an Alexandria city dredging company, Smoot Sand and Gravel, began to dredge the wetlands area that Dyke Marsh began to erode. His presentation made several references to the early years of reporting about Dyke Marsh by the Alexandria Gazette as part of his documentation of its colorful early human history. In one story the Gazette characterized it as “a grand wild place.”

Left without careful restoration efforts, the rate of loss of the wetlands has gone from an area covering 180 acres in 1940 to 53 acres by 2010. The U.S. Geological Survey estimates that the loss is accelerating and that it is currently eroding at the rate of 1.5 to two acres per year on average. Unless something is done to stop the erosion, Dyke Marsh will be gone in 30-40 years.

Currently, the National Park Service is in the midst of an overdue Environmental Impact Statement and by mid-2013 will issue a report with recommendations to arrest the decline and restore the marsh for the long term. There will be a public comment period including a public hearing before a final Environmental Impact Statement is issued.

Stopping the decline will protect a vast array of fish and wildlife that call Dyke Marsh their home. It is a “rare, unique freshwater tidal marsh” in the National Park system, and the only tidal wetlands of its kind according to Dr. L.K. Thomas, retired research biologist with the National Park Service who has studied Dyke Marsh for the past 53 years. He spoke about the marsh’s special place in the world as a vibrant ecosystem with many unique features, and his desire that the federal government fund a restoration program to ensure it’s long-term viability.

A restored and healthy Dyke Marsh would continue to serve as a freshwater wetlands area which is now home to 300 species of plants, 6,000 arthropods (insects, crustaceans, arachnids), 38 species of fish, 16 types of reptiles, 14 types of amphibians, and more than 230 species of birds. One Georgetown University entomologist said, that counting bacteria, there may be 18,000 different organisms in Dyke Marsh. In addition, the marsh also serves as a water filter, and a buffer against flooding, although its diminished wetlands acreage consequently has for the present time been less effective than it has been in the past.