Nutria captured in Maryland

Washington Post photo by James A. Parcell

HOBOKEN, N.J.

ARMED WITH voracious appetites and explosive reproductive capabilities, giant rat-like swamp creatures from another continent lurk deep within a dark, otherworldly bayou. Rustling near the base of an ancient moss-covered tree reveals an invasive rodent called the nutria — scientific name Myocastor coypus — which has unleashed a torrent of environmental devastation along the Gulf Coast in the wake of hurricanes Katrina and Wilma. It sounds like something out of a 1950s horror movie but these semi-aquatic mammals are wreaking havoc right now on the natural ecosystem of Louisiana and other nearby states. Reports indicate that over 300,000 acres of wetlands have been destroyed by nutria in Louisiana.

But it’s not their fault. Humans are to blame for importing nutria to Louisiana in the 1930s from Argentina, Bolivia and Brazil to profit from harvesting their furs. When the fur trade collapsed in the early 1980s, nutria were released into the wild, where they multiplied to prolific levels. Since then, nutria have dramatically altered the environment by consuming vegetative cover and increasing soil erosion, which synergistically magnifies the most pressing issue — loss of wetlands. These invaders have also damaged croplands, especially rice paddies in Texas.

And the critters have spread well beyond Louisiana to become a major problem all along the Gulf of Mexico, from Texas to Florida. They have moved north along the Atlantic coast from Georgia to Delaware and Maryland, where particularly fierce battles against them have been fought.

Rhode Island’s attractive habitat has not witnessed a nutria invasion yet. However, according to David Gregg, of the Rhode Island Biodiversity Center, global warming may well let these critters to survive in climates previously thought inhospitable. Gregg foresees nutria as a possible danger. To be on the safe side, Rhode Island law requires a permit for importation/possession of nutria and no breeding is permissible without prior notification of the Rhode Island Department of Environmental Management. Unlike many other states, Rhode Island seems fully alert and prepared for any possible threat.

Can these aquatic South American invaders be stopped? One way is simply to trap them as humans have done for centuries. Using bait such as corn, alfalfa, cabbage, carrots and just about any other crop, metal cages or snares are set in areas where nutria are prevalent. Louisiana is offering $5 for each one “harvested.”

Another way to reduce the nutria population is to bring 21st Century technology to the aid of trappers and hunters who are still using methods going back to the Stone Age. Known as chemical prospecting, this innovative research field used advanced scientific procedures to conduct pharmacological screening of natural biological compounds. Simply put, scientists try to identify chemicals made by animals that may prove useful to humans. Many conservationists view chemical prospecting as the major impetus for preserving the biodiversity of the planet. For example, the anti-cancer drug taxol was developed from the Pacific Yew tree, which could have been irrevocably lost through deforestation. Chemical prospecting may hold the key to curing numerous illnesses and solving countless other problems that may develop in the future.

Now Athula Attygalle, of the Stevens Institute of Technology, has implemented this approach in the battle against the nutria. Recently, Professor Attygalle has identified the specific chemical compounds that act as natural attractants that consistently lure nutria into traps. Application of these attractants offers an environmentally acceptable alternative to poisoning and may prove more effective than shooting campaigns or construction of expensive exclosure fences, as in Louisiana. As Attygalle points out, some field testing has been done in Louisiana and he stands ready to lend his expertise to any plan that may be developed for other areas.

Of course, it is possible that nutria may become wary of the scent since, as mammals, they have high intelligence. However, “they must escape the first trap episode in order to use the knowledge” notes Attygalle. The other factor that must be considered in using Attygalle’s attractant is its short life-span. Being volatile compounds, they may last only about a week but should be inexpensive enough to replace frequently.

The nutria outbreak speaks to a much larger, insidious phenomenon obliterating cultures and decimating natural ecosystems on a global scale — homogenization. As international travel and commerce has increased over the past half century, a myriad of species has been unknowingly transported across the planet, often to regions with no natural defense against the new arrivals. Is it possible that eventually regional plant and animal inventories may become the same everywhere? In a time when people can so readily travel the world, transportation of invasive species in the form of seeds, pollen and live animals has become one of the most critical threats to global biodiversity.

Only by integrating supermodern technology with ancient hunting and trapping techniques can we hope to keep our planet’s ecology in balance, and stop the dreaded nutria invasion.

Silvio Laccetti is a columnist and a longtime professor of social science at Stevens Institute of Technology, in Hoboken, N.J. Charles Kontos is an environmental engineer who also holds a master’s degree in wildlife biology. He has conducted numerous field projects, notably on the return of fisher cats to New Jersey. They may be reached at slaccett@stevens.edu.