Eugene Olmi, owner of a duck blind on the edge of Dyke Marsh south of Alexandria, says he's been hunting ducks in and around the area with a Maryland license since World War II.

But the National Park Service and members of local environmental groups are concerned that the hunting at this particular blind is disturbing thousands of migrating birds that flock to the marsh.

"I'm not going to stop until hunting is eliminated around Dyke Marsh, which is part of a national park," said John Byrne, George Washington Memorial Parkway superintendent for the National Park Service. "The federal government has a right to protect wildlife in its jurisdiction."

The blind site, in shallow water beside a small island near the southern end of the marsh -- several hundred yards from the parkway -- is "licensed by Maryland, but appears to be clearly in Virginia and Fairfax County waters," said Byrne.

"This blind exists only because of bureaucratic convolution, with everybody -- Park Service, Fairfax and Virginia -- throwing up their hands" and saying it's not their problem, said Joe Stephens, a member of Friends of Dyke Marsh.

Ed Risley, a member of the Audubon Naturalist Society board and of Friends of Dyke Marsh, said he hadn't seen the duck blind site until this week, "but I'd heard about it and we're concerned about it."

Olmi, a former president of the Fairfax County Chamber of Commerce, said he and friends have shot about seven ducks at the site so far this year and about six last year. He said he checked with both the Park Service and Fairfax County Sheriff M. Wayne Huggins before first hunting at the Dyke Marsh site two years ago.

"The sheriff said [Fairfax] County jurisdiction stopped at the parkway, which is federal land, and Maryland owns to the high-water mark [on the Virginia shore] so he and his people wouldn't be bothering me.

"And then I talked to the Park Service and they said 'we don't want you out there, but you're legal,' " he said.

Sheriff Huggins said yesterday he remembered talking with Olmi several years ago, "But I never gave him permission to hunt, since the sheriff's office has never had jurisdiction over game laws."

"Congress dedicated Dyke Marsh to protect wildlife and it's one of the few wetlands in the entire Washington region," said Stephens. "We're not an antihunting group, but there's no way a hunting blind can be legal on the edge of the marsh."

Byrne said yesterday he is concerned not just about duck safety, but public safety, with hunters shooting within a few hundred yards of the parkway and near a popular marina.

"We're only using No. 6 birdshot, which is like shooting sand, and doesn't even go 100 yards," Olmi responded.

"If somebody's real upset about this, I say, hey, let me finish the season and I'll stop shooting or move down the river," said Olmi.

The split duck hunting season closed last Friday and opens again for another month starting Dec. 10.

Maryland officials who oversee hunting blind sites on the Potomac could not be reached for comment yesterday, but state Natural Resources Police Sgt. Edward Frere said "you know one way to avoid this is for the Park Service to buy up the hunting blind sites."

Under Maryland law, the Park Service, as the landowner, could buy an annual duck blind site license, effectively precluding anyone else from buying one there.