CAMBRIDGE, MD (January 19, 2005)
(photo: Tom Darden)
When spring comes to the marshes of Blackwater
National Wildlife Refuge, there will be a more luxuriant growth of grasses and
rushes than in recent years. Nutria have NEARLY disappeared from this fragile
landscape, trapped by man in an extraordinary demonstration of applied ecosystem
restoration. But the Blackwater nutria-free zone is an island in an expanding
sea of hungry exotic rodents that threaten to reclaim their vanquished habitats.
Nutria are large aquatic rodents native to South America. They became established
in Maryland when a few animals escaped from a fur farm in the 1930's. Unlike the
smaller native muskrat which grazes on marsh grasses, nutria literally consume
tidal marshlands, leaving mudflats in their place. Scientists believe that
there may be 50,000 nutria in the wetlands of the Chesapeake's Eastern Shore.
Chesapeake Bay marshlands are the nursery of the Bay, providing a home for
invertebrates, birds, mammals and fishes, often during critical juvenile life
stages. Ecologists realize that if the marshes are lost to nutria, the basis
of the Chesapeake food chain will be shattered.
State and federal agencies have formed the Chesapeake Nutria Partnership
to battle the rat-like invaders. Trappers from the U.S. Department of Agriculture
ply the marshes of Dorchester County, trapping nutria and establishing a
"nutria-free zone" in what was once the most heavily infested marshland in the
A new economic evaluation of the effects of an escaped population of nutria, shows
that the rat-like creatures will have an enormous cost in lost revenue to the State
of Maryland in addition to their devastating ecological impact to the Chesapeake Bay.
The study, performed by Southwick Associates, an independent economic consulting group
- In 50 years, losses to the overall economy could exceed $35 million annually
- Without decisive action, more than 35,000 acres of Chesapeake Bay marshes could be destroyed by nutria in 50 years.
- Maryland watermen will be hardest hit, with lost productivity and lost jobs for this already economically embattled sector.
The good news is that wetlands that have been denuded by nutria can make a
remarkably recovery if the nutria are removed before too much time has elapsed.
The re-birth of marsh grasses and their fish and wildlife inhabitants within the
nutria-free zone has been spectacular. But as the nutria-free area expands, the
front lines in the war on nutria become longer and the trappers are spread thinner.
Without expanded funding, the nutria partnership could falter and fail, even as
it has proven that nutria can be eradicated and the marshes can be saved.
For further information about nutria, see
For more information about other Invasive
Species of Concern, visit www.mdinvasivesp.org or call MDA at 410.841.5920.
photos available electronically on request.