|
|
|
|
FODM President Glenda Booth has written an article describing Dyke Marsh as one of Northern Virginia's most important environmental treasures. The article was published in the October 2006 issue of Virginia Wildlife magazine. A Sanctuary Amid the Sprawl
Most harried motorists gridlocked on Northern Virginia’s Capital Beltway hardly notice the wetlands complex just south of the Woodrow Wilson Bridge as they crawl across the Potomac River in one of the nation’s worst traffic bottlenecks. The mudflats and marshes teem with life. This is the Dyke Marsh Wildlife Preserve. Wetlands, like Dyke Marsh, are transitional zones where the water meets the land and one of nature’s most dynamic ecosystems. Kirk Havens, a Virginia Institute of Marine Science scientist, says, “In an area roughly the size of an average desk top, there can be as many as 8,300 animals.” In a new film celebrating the marsh, Virginia U.S. Senator John Warner calls the marsh a “magnificent little oasis.” Jeff Trollinger, the DGIF’s Virginia Birding and Wildlife Trail manager, agrees: “Dyke Marsh is one of our premiere sites on the birding trail in Northern Virginia. It is particularly nice because it is close to a large population area and allows folks to not drive far and still get a quality wildlife experience.” Congress Recognized Its Value The U.S. Congress designated Dyke Marsh as part of the National Park Service system in 1959, “so that fish and wildlife development and their preservation as wetland wildlife habitat shall be paramount.” (Public Law 86-41) Today, tucked in a metropolitan area of almost 5 million people, Dyke Marsh, at 5,000 to 7,000 years old, is a rare remnant of the many freshwater tidal marshes that once lined the Potomac. It is half its 650-acre size when Captain John Smith sailed by in the 1600s. Nineteenth century farmers tried to convert it to farmland by walling it in with earthen dikes, hence the name (the Colonial spelling was “dyke”), a then-legal form of filling wetlands. Later, the marsh was gouged with 30-foot holes when it was dredged for gravel. A long-time volunteer steward of the marsh, Ed Risley laments in the film, “I used to lie in bed at night and hear the dredges eating up the marsh.” It is pocked with dredge spoil and big chunks of concrete protrude, reminders of the 1960s when the marsh was a dumping ground for construction debris. While Congress’s action halted those abuses, challenges remain today.
Biologically Rich At 380 acres, the wetland has three major zones or plant communities: the marsh proper (tidal freshwater marsh), the floodplain forest, and the swamp forest. Of known species, there are 300 plants, 6,000 arthropods, 38 fish, 16 reptiles, 14 amphibians, and over 230 birds. In 2003, 46 species of birds were confirmed breeding in Dyke Marsh and six additional species were probable breeders. A May arthropod walk led by Dr. Edward Barrows, of Georgetown University, quickly expanded to a biodiversity walk. The group froze watching a black rat snake vanish into a woodpecker hole and then languidly droop its head out, sated. They examine the fake “wild-eyes” of the one-inch click beetle and watch shad fingerlings shimmer in the shallows. They marveled at the large teardrop-shaped Baltimore oriole nest woven onto sycamore limbs as cottonwood seeds floated in the air and gently landed on the spatterdock. Barrows said there are 18,000 species of organisms in Dyke Marsh. There are muskrat, brown bats, foxes, cottontail rabbits, gray squirrels, shrews, northern water snakes, and snapping and painted turtles. Among plants and trees are narrow-leafed cattail, arrowhead, arrowhead arum, pickerelweed, sweetflag, spatterdock, northern wild rice, swamp rose, buttonbush, alder, red osier dogwood, elm, sweetgum and maple, green and pumpkin ash, black willow, spicebush, and arrow-wood. Mummichog, pumpkinseed, bluegill, banded killfish, largemouth bass and tessellated darter make the Dyke Marsh nursery their home. Its waters support fishing and waterfowl hunting and it is a stopover point for many migratory birds. Dyke Marsh has the only known nesting population of marsh wrens in the upper Potomac tidal zone, a species once found all along the marshes of the Potomac River. Sandy Spencer, wildlife biologist with the U.S. Fish and Wildlife Service, Rappahannock River Valley National Wildlife Refuge, has studied them extensively. She says that in the late 1800s and early 1900s there were hundreds of singing males; by 1999, only 34. Because marsh wrens have very narrow breeding territory preferences, the habitat loss at Dyke Marsh has meant even less suitable breeding habitat. In 1999, only 15 percent or 56 acres of wetlands was narrow-leaf cattail marsh adjacent to water or subject to flooding, the wrens’ preferred breeding habitat; and of that, only about four percent or 15 acres was used for breeding. Challenges Dyke Marsh is at the northeast corner of Fairfax County, population one million, next to the city of Alexandria, population 135,000. Squished up against the George Washington Memorial Parkway, a busy thoroughfare, and a bike trail, the sounds of marsh life compete with the cacophony of suburbia – backyard barbecuers, steady traffic, sirens, roller-bladers, walkers, strollered babies, bike bells, airplanes, commercial barges and general river traffic. Forty-two square miles of residential and commercial development drain into the marsh, It’s battered by polluted runoff, contaminated sediment, lawn and golf course chemicals, upland erosion and air pollution. Eighty percent of Fairfax County’s streams are in fair to poor condition. The Potomac River watershed was given a C+ in October 2005 by the Interstate Commission on the Potomac River Basin and parts of the river are on the state’s “dirty rivers” list. Nutrient enrichment or eutrophication of the river by fertilizers, sewage and pollution upstream degrade “the nation’s river.” The marsh suffers from an explosion of at least 78 non-native plants, including porcelain berry, English ivy, Japanese honeysuckle, Asiatic bittersweet, yellow iris, the common reed (Phragmites australis) and purple loosestrife. Some plants have become extinct, according to Donald Kelso’s 1993 report to the National Park Service. Despite its wounds, Dyke Marsh is, as naturalist Louis Halle wrote in Spring in Washington in 1947, “the nearest thing to primeval wilderness in the immediate vicinity of the city [Washington].”
Restoration Hopes Park Service officials have determined that restoration of the marsh is both “feasible” and “desirable” and the Friends of Dyke Marsh, a local advocacy group, have made restoration a top priority. They emphasize that the marsh is one of the most significant temperate, climax, narrow-leafed cattail, tidal, freshwater, riverine marshes in the U.S. National Park System and that human activity will continue to degrade the marsh without action. The Park Service is seeking $500,000 for an environmental impact statement, the first step. Pledging his support, Congressman Jim Moran has labeled restoring Dyke Marsh an “important conservation effort.” Senator Warner wants to “bring it back to its full grandeur.” Fairfax County state Senator Toddy Puller says, “Dyke Marsh is a national treasure that must be restored and preserved. One of the last remaining freshwater tidal marshes along the Potomac River, it is an irreplaceable wetland that must be saved for generations to come.” Former President George H. W. Bush established a policy of no net loss of the nation’s wetlands and President George W. Bush expanded that to an “overall increase of wetlands in America each year.” The Commonwealth has committed to restoring wetlands and the health of the Potomac River and Chesapeake Bay. A restored Dyke Marsh can support more wildlife, more biodiversity, more ecological services, and increase aesthetic, educational and recreational opportunities for the nation, in a highly urbanized community that provides few wildlife viewing opportunities, beyond the typical backyard gray squirrel. The Washington metropolitan area will add 1.6 million people in the next 20 years. As local developer Ray Smith laments in the film, Northern Virginia’s population has quadrupled but “we’ve not added any Dyke Marshes.” “Winter or summer, if you wish to match yourself against a wilderness, I can recommend nothing better than the tidal marshes around Dyke…” wrote Halle in 1947. Dyke Marsh enthusiasts fully agree.
|
|
Home
Friends of Dyke Marsh, Inc. is a
non-profit §501(c)(3) organization.
|
