WASHINGTON – One year after a nutria eradication program began on the Eastern Shore, trappers have killed about 5,000 of the estimated 75,000 critters in Dorchester County and officials said it is still too soon to tell if the effort will work.
“We think we can eradicate them but we’re not sure,” said Dan Murphy, a U.S. Fish and Wildlife Service biologist. He is one of the leaders of a nutria management team that includes federal, state and private agencies and organizations.
The team will meet Monday to assess the progress of the eradication effort so far and see “where the obvious next steps are,” said Jonathan McKnight, associate director for habitat conservation at the Maryland Department of Natural Resources.
Since trapping began last October, the project has focused on about 13,000 acres in the Blackwater National Wildlife Refuge. Plans call for trappers to eventually expand into adjacent areas totaling 60,000 acres, including the Fishing Bay Wildlife Management Area and Tudor Farms, a privately owned hunting preserve.
But that will take money. For nutria eradication to work in the Chesapeake Bay, Murphy said the program needs more trappers — about 45 in all. It currently has 17 trappers.
Congress in January passed the Nutria Eradication and Control Act of 2003, which authorized up to $20 million over the next five years for nutria in eradication in Maryland. But funds have not yet been appropriated for fiscal 2004, and aides to Rep. Wayne Gilchrest, R-Kennedyville, said next year’s allocation may be much less than the appropriated amount.
Nutria were introduced to Blackwater in 1943 for their pelts, but when that market failed, the animals were allowed to grow unchecked. Since then, their numbers have climbed to an estimated 35,000 to 50,000 in Blackwater, and up to 75,000 in Dorchester County, according to the Natural Resources Department.
Over the years, the invasive species has wreaked havoc on the wetlands. The South American rodents, which look like rat-tailed beavers, eat wetland plants — roots and all. Without the plants to bind it, the soil erodes, making it harder for new plants to grow.
The loss of plants and marshland means the loss of habitat for birds, fish and crabs. Commercial fisheries and local ecotourism then lose value as bird, fish and shellfish numbers decline, according to the Department of Natural Resources.
The department attributes the loss of over 7,000 acres of Blackwater salt marsh over the last 40 years to a combination of effects from nutria feeding, the rising sea level and soil erosion.
“We really need to do something about it,” Murphy said.
What they have been doing is marrying old and new technology — old-fashioned traps and satellite tracking — to kill nutria and keep track of the trappers’ progress against the animals. But the process is still slow-going, and will get harder as the density of nutria decrease.
“It’s going to take a very long time,” to kill all the nutria in Maryland at the current rate, McKnight said.
But he is optimistic.
“I would like to see us rounding up the last of these creatures 10 years from now,” McKnight said. “I think it could be done, if we were given the resources to do it. And I think that compared to what we stand to lose . . . it would be foolish for us not to make that investment.”
Nutria have invaded other states, which have tried to control the animals with varying success. Because nutria in Louisiana are not constrained by any natural boundary like the Chesapeake Bay, for example, officials there focused their efforts on controlling, not eradicating, the population.
But officials have more hope for Maryland, because its geography and climate differs from Louisiana’s.
“Ours is a different situation,” Gilchrest said. “We have natural geography that confines them,” and colder winters that the rodents weather poorly.