Protecting a Tidal Habitat From Pollution and Erosion

Within sight of the Woodrow Wilson Bridge, high-rises in Alexandria and the emerging National Harbor project in Prince George's County, Mike Bowen peered through his telescope at a bundle of sticks in the Potomac River shallows one recent day and spotted an osprey nest. Spring will also bring blooms of cattails, sweet flag and spatterdock to the freshwater tidal habitat closest to Washington.

But what often floats into view at the Dyke Marsh Wildlife Preserve is trash. "It keeps coming back," said Bowen, a birdwatcher from Bethesda. "It's disgusting."

The National Park Service is beginning a $500,000 environmental impact study of how to restore and preserve the 485-acre marsh just off the George Washington Memorial Parkway in Virginia. The wetlands, prized by birders, naturalists and bicyclists who pass by on the Mount Vernon Trail, are home to painted turtles, water snakes, orioles and tundra swans.

Congress authorized the study last year in an effort to halt erosion from natural and man-made causes. Details on the study's scope are still being determined, but it could look at the effect of heavier water taxi traffic and other activities such as boating, fishing and kayaking.

One Saturday this month, the Park Service sponsored a litter cleanup of the marsh and the Belle Haven Marina, situated on a man-made peninsula within the preserve. About a dozen marsh enthusiasts came out to help pick up trash.

The marsh, named for a variant spelling of "dike" after a landowner in the 1800s tried to turn it into farmland, had been cleaned up in February. But an area north of the marina was littered with beer bottles and soda cans.

"I didn't realize what a scourge Styrofoam was," said Bonnie Lilienfeld, a museum curator from Alexandria. She and her son, Aidan, 12, on their second marsh cleanup, used long sticks to retrieve trash and stuff it into bright orange bags.

Jessica Overcash, 17, a West Potomac High School student, was participating to earn community service credits.

"It makes me feel good to know the places where I live are clean," she said, retrieving a dirty water bottle from the reeds.

A few days earlier, park ranger Miguel Roberson walked along the waterfront, his boots crunching in the path that parallels the river.

"It's a natural marsh," he said. "There's not many like it."

Dana M. Dierkes, a Park Service public affairs specialist, strolled alongside Roberson.