Blackwater's nutria find little refuge from trappers

Fear of rodents' spread in region tempers success

October 28, 2003|By Chris Guy | Chris Guy,SUN STAFF

BLACKWATER NATIONAL WILDLIFE REFUGE - A year after launching a methodical slaughter of nutria, the South American rodents that are destroying vital marshes here, wildlife officials say they're buoyed by the early results. But they are deeply concerned that the creatures might be expanding their range into Delaware and across the Chesapeake Bay.

So far, a team of professional trappers, employing everything from old-fashioned steel traps to British "otter hounds" to hand-held geo-positioning technology, has killed more than 5,000 of the estimated 30,000 to 50,000 nutria in Blackwater.

The animals are a portion of a population that has grown to 75,000 in rural Dorchester County since they were introduced to boost the fur trade 60 years ago.

Nutria, described by one official as "25-pound water rats with orange teeth," are a cousin of native muskrats. But they feed on the roots of marsh grasses, causing erosion. In the 24,000-acre Blackwater preserve, they have destroyed as many as 8,000 acres of habitat that is crucial for waterfowl, fish, crabs and other species.

Covering more territory

"Obviously, Blackwater is the hotbed for nutria, the place where they were first introduced, but we are trapping them [in other places,] too," said John Wolflin, who heads the Chesapeake office of the U.S. Fish and Wildlife Service.

"We have a success story here, but we are starting to see signs of them expanding," Wolflin said.

Officials from the state Department of Natural Resources say they have killed a few of the animals that were discovered in Anne Arundel County.

Small populations of nutria also have been reported in Somerset County and other areas of the Lower Eastern Shore.

Nutria have been spotted on the Delaware coast in the Prime Hook and Bombay Hook national wildlife refuges, said Terry Villanueve, refuge manager at Bombay Hook near Dover.

"We discovered a few of them last winter," Villanueve said. "We need to do an assessment to find out how many there might be and go from there."

Eliminating nutria is a key element of an overall plan to restore eroded marshes at the Blackwater refuge.

A pilot program sponsored by the National Aquarium in Baltimore, in which students replanted 15 acres of marsh grass, offered a glimpse of a more extensive effort officials hope eventually could replace lost habitat throughout the refuge.

Vital habitat

"This is tremendously valuable habitat for just about any species we can think of," said Jonathan McKnight, DNR's associate director of habitat conservation.

"If we lose the marshes, we lose the Chesapeake Bay as a functioning ecosystem," McKnight said.

Since last fall, 14 trappers have concentrated on a 13,000- acre tract in Blackwater, carefully dividing the area into 352 plots and killing about 12 nutria per plot.

After three months - the average reproductive cycle for the hyper-fertile rodents - the trappers go back through the same grids, looking for stragglers they might have missed the first time or for other animals that have moved in.

Dead nutria are left to an inglorious end, scattered around the refuge by the trappers for bald eagles, buzzards, foxes or other meat-eaters.

"These animals have no known predators, no known diseases," said Wolflin. "The only known killer is temperature. Cold weather is very hard on them."

A concerted effort

The nutria program is supported and directed by a coalition of federal and state agencies and nonprofit groups as diverse as the Chesapeake Bay Foundation, the Salisbury Zoo and a state forestry trade group.

The program began in 1999 and has cost about $4.2 million since then, though the concerted effort to kill the animals is only a year old.

Congress has authorized up to $20 million for a five-year plan that wildlife experts think is a long enough period to eradicate nutria throughout the Delmarva peninsula. Lawmakers have not appropriated the money, however.

Making a difference

Rick Elzey, a 49-year-old native of the tiny Dorchester village of Crapo who works on the trapping team, says he knows the effort has been effective.

"I'm right out there on the marsh where I've spent my whole life, and I can see the difference," Elzey said.

"I was born here, and I can tell you something: We're getting them in Blackwater," he said.

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