The shore of the Potomac River, a magnet for joggers, bicyclists and fishermen, has attracted a new crowd this year: hunters.

An explosion in the waterfowl population, attributed to improvement in the river's health, has spawned a proliferation of duck blinds in the waters south of Alexandria in Fairfax County along the George Washington Memorial Parkway. But the hunters waiting in ambush aren't the only ones up in arms.

Residents along the shore, particularly the stretch from Jones Point to Mount Vernon, have become alarmed by the sudden sounds of gunfire so close to where they live and play.

"You're just not used to hearing gunshots in your neighborhood," said Christopher Wright, 33. "If they were to screw up or misfire, they probably could do a lot of damage to windows or people or whatever."

Gerald W. Hyland, the supervisor-elect for the Mount Vernon District, is leading the charge to prohibit hunting along the county shore. Said Hyland: "Hunting has no place in an urban-suburban, heavily populated area like Northern Virginia."

While hunting is prohibited in the county except under certain conditions, the waters along its shores are fair game, according to officials. Some waters are under the jurisdiction of Virginia; others are the responsibility of Maryland. Waterfowl hunting is allowed under the appropriate state licensing laws.

Further muddying the jurisdictional waters are federal laws that prohibit hunting in certain areas, such as in Dyke Marsh south of Alexandria. Acquired by an act of Congress in 1959, the federal bird sanctuary is carefully monitored by the Friends of Dyke Marsh and managed by the National Park Service.

Hank Snyder, a Park Service ranger for the area, said he had counted about 12 duck blinds along the strip of Virginia shore this duck-hunting season, which opened briefly last month and resumes again in a few weeks. While they are legal blinds, Snyder said the record number has generated a raft of queries from residents on the heavily populated Virginia side. They wonder: "Hey, we saw somebody out in the river shooting ducks. Isn't that unusual?"

According to Snyder, as the river has become cleaner in recent years, aquatic vegetation, including hydrilla, has flourished. The rich new food supply has attracted more waterfowl and, hence, more hunters, he said.

So far, Snyder said, the hunters have been properly licensed and responsible. He said the exception may be those who have built one very visible blind, which has become the focal point for residents' concerns.

Located an estimated 30 to 50 yards from the Virginia shoreline and the parkway, it is technically in Maryland waters but in plain view in Virginia -- to diners at the Cedar Knoll Restaurant, worshipers at the Church of Jesus Christ of Latter-day Saints and joggers along the Mount Vernon jogging path.

The blind also illustrates the variance in state laws. Were the blind in Virginia waters, it would have to be at least 100 yards from the road, said Mack Lloyd, an electrical contractor and avid hunter. Yet while he noted it is "100 percent a legal blind," he and other hunters said they believe its owners should honor the Virginia law anyway.

"It's a duly licensed Maryland blind," said a hunter who retreated from the blind one rainy morning last week. Asked about safety concerns, the hunter, waving toward the jogging path and then the river, said: "I don't hunt this direction; I hunt that direction."

"That's what they say, but if a flock of ducks flies behind them, you know they're going to turn around," Jack Abbott, a member of the Virginia Audubon Naturalist Society, said of hunters in general. Abbott, the coordinator of a bald eagle breeding survey, is concerned that an eagle will be mistakenly downed by an zealous hunter.

In an effort to ban or reduce hunting along the shore, Hyland has appealed to U.S. Interior Secretary Donald P. Hodel, hoping he will use his authority to regulate hunting under the Endangered Species Act of 1973. According to Abbott, as many as five bald eagles can be spotted along that stretch of the river daily.

In addition, Ed Risley, a member of the Audubon Naturalist Society and Friends of Dyke Marsh, said his groups and others will propose that federal, state and local officials meet jointly and discuss the environmental and safety concerns.

"I'm not accusing the people who are using the blinds of being a menace; they're responsible people," said Risley. "But there is always a chance that they will be irresponsible."

To date no injuries have been reported, said Snyder, although there have been some close calls -- the wounded goose that landed a few feet away from some joggers and the parked car pelted by pellets.

One longtime resident, Joan Lyon, said a neighbor whose house is on the river is afraid to go out her back door. Said Lyon: "I think we have the potential for a tragedy."