DEAL ISLAND -- A team of federal trappers that killed 10,000 nutria in the sprawling Blackwater National Wildlife Refuge has a new mission: Ridding the rest of the Eastern Shore of the invasive herbivore.
The South American rodents destroyed 8,000 acres of delicate marshland in the 24,000-acre Blackwater refuge before government hunters wiped them out. Then nutria were targeted in the Fishing Bay Wildlife Management Area and other publicly owned tracts in Dorchester County.
Now the trappers are moving south, stalking smaller pockets of nutria on both public and private land here in this remote corner of Somerset County and other parts of Lower Eastern Shore. In the future, officials predict a nutria-free Chesapeake, maintained by systematic spot checks.
"Blackwater is done. It's clear, but there is a biological fire burning all around," said Jonathan McKnight, a wildlife biologist with the Maryland Department of Natural Resources, one of a host of agencies working together on the program, which started in 1999. "Unchecked, nutria pose a serious threat to the entire bay ecosystem."
Environmental damage by non-native species such as nutria often leave wildlife specialists saving some populations but not others. Migratory birds such as Canada geese and trumpeter swans, for instance, are rigorously protected by state and federal laws. Meanwhile, resident Canada geese and huge flocks of snow geese are hunted with fewer restrictions.
Maryland environmental officials have tried for years to eliminate non-native mute swans by shaking their eggs or euthanizing the majestic birds because they feed on underwater grasses that provide cover for crabs and other creatures.
Nutria were brought to Maryland in 1943 to be raised for fur, but their pelts never became popular. They are nearly three times the size of native muskrats and easily recognized by their distinctive orange teeth. They're a problem because they destroy marshland when they feed, ripping aquatic plants out by the roots, unlike muskrats, which nibble the tops of water plants.
Without a stabilizing network of roots - of needle bush, salt hay and water bushes (which trappers say are like catnip for nutria) - pungent black marsh is washed away with every tide or wind.
The erosion destroys crucial habitat for migratory birds, fish and crabs, among dozens of other species, leaving brackish open water.
Nutria leave black patches of freshly dug mud and droppings amid a light green sea of water plants. The evidence is easy to spot for the dozen methodical trappers at work here. Each man is working 400 to 600 acres of marsh in the Deal Island Wildlife Management Area near the Wicomico River, where they recently trapped 200 nutria in two weeks.
According to field supervisor Stephen Kendrot, a wildlife specialist with the U.S. Department of Agriculture, the telltale signs of nutria here are the most extensive damage he has seen in a marsh in nearly two years.
"As the marsh is denuded, salt water intrudes farther and trees are destroyed," Kendrot said. "It's really a chain reaction to the environment. There are hundreds of species of plants and animals that depend on this marsh"
Often, the biggest challenge, Kendrot says, is figuring out who owns land in the water-soaked labyrinth of property lines, then persuading sometimes-suspicious landlords to allow federal trappers on their property.
"Landowners approach us sometimes, but I spend lots of time perusing tax maps, prospecting for property owners who want to participate," Kendrot said. "Generally, the farther away from Blackwater, the less aware they are of the problem, or maybe they're leery of the government on their property."
Lingan "Lin" Spicer, a 58-year-old farmer from Church Creek, says he had little interest until he began to see for himself the damage the animals were doing to a 500-acre parcel of timber and marsh he owns near Blackwater.
It was downright unnerving, Spicer said, to watch as nutria foraged in corn and wheat fields adjacent to his marsh.
"I was one of the toughest critics, but I'm glad to eat crow," Spicer said. "I don't know of another critter as prolific as nutria, and yet this program has been a big success. I'm not the skeptic I was."
Others took little convincing as nutria damaged large tracts of marsh, exacerbating rising sea levels that are occurring all around the bay.
Ed Soutiere, who manages a 6,200-acre Dorchester hunting preserve for billionaire financier Paul Tudor Jones, said he was an early supporter of the program. In the past two years, a private trapper contracted by the estate, Tudor Farm, caught just 15 nutria in an area where thousands once thrived.
Hunters and other visitors to the Tudor property report an eerie silence instead of the constant lamblike bleating of nutria heard across the marsh.
"For us, it was important to get rid of them," Soutiere said. "There was no question the nutria were a catalyst for erosion. Forty-percent of our marsh has been lost since 1989. It's obvious the only way this will work is to keep at it. If we dabble at it, we might be here doing this for the next hundred years."
Wildlife biologists such as Kendrot and McKnight believe the program could meet its goal in another seven years. So far, the program has cost about $1 million a year, Kendrot said.
"What Blackwater has shown us is that the nutria program can work," McKnight said. "We have a reachable goal, and it's a worthwhile project to protect the marshes of the bay."