Nutria
Destroying Marshes The Old Fashioned Way

In the waters of Louisiana coastal marshes, chisel-toothed creatures the size of small dogs swim, eat and multiply. They number in the millions and threaten the existence of the state’s wetlands. Commonly called “nutria,” the spread of these South American natives has been devastating.

Imported to Louisiana from Argentina in the 1930s, nutria were raised domestically for several years. Whether they escaped or were intentionally released remains unknown. But, by one means or another, they entered Louisiana’s marshes, where they have flourished.

Once a boon to the trapping industry, ever-increasing numbers of these large South American rodents now destroy coastal marsh the old fashioned way – they eat it. In their search for food, nutria graze heavily upon the plants that bind the fabric of the marshes together. Mature nutria weigh an average of 12-16 pounds, and the animal’s daily consumption of plants may equal 25 percent of its body weight.

With population densities as high as 20 animals per acre, nutria can quickly remove all vegetation in a wetland. And once coastal wetlands have been I denuded, they can no longer withstand storm surges and tidal erosion or provide a buffer to inland areas.

Imagining that a single animal species could endanger vast expanses of marsh may be difficult; however, the threat is real. Through aerial surveys, Louisiana Department of Wildlife and Fisheries personnel have identified thousands of acres of marsh where nutria have removed all vegetation and left little more than open water. As Allan Ensminger, retired chief of the department’s Fur and Refuge Division, says, “The influence of nutria alone is sufficient to cause the marshes to continually decline, jeopardizing their existence.”

During the early 1960s, a demand for nutria pelts produced attractive fur prices and a corresponding incentive for trappers to harvest the animal. For a quarter of a century, trapping curbed nutria population growth. Unfortunately, fur prices fell in the mid-1980s and trapping diminished to insignificant levels. Since then, nutria populations have grown dramatically, as has the damage the animals inflict.

With countless numbers of nutria now living in coastal wetlands, experts are diligently seeking solutions. Greg Linscombe, program manager for the Fur and Refuge Division, Louisiana Department of Wildlife and Fisheries, says, “If we can reduce the nutria population by at least 500,000 each year, the vegetative damage caused by these animals will be dramatically reduced.”

To increase the harvest of nutria, the department initiated an innovative approach. Its strategy involves developing domestic and international markets for nutria meat, thereby creating a financial incentive for trappers. Nutria recipes abound, international business concerns have expressed an interest, and there is hope we might see an expansion in the harvest of this chisel-toothed threat to Louisiana’s marshes.