It Wears Pelt Like Richest Fur, Denudes Marsh : Ecology: The nutria’s insatiable vegetarian appetite puts Louisiana’s floating islands of vegetation in peril. The state hopes to encourage trapping to reduce the population of the critters, also known as rat beaver or coypu.

There are floating islands in Louisiana--islands where herons nest in the branches of myrtle trees, alligators cruise beneath the roots and slow ripples spread out with every step you take. The mat of leaves, stems, and roots sinks beneath your feet and rises again behind you.

But now these floating masses of vegetation are in danger, all because of the insatiable appetite of a strange critter called variously the rat beaver, the coypu or the nutria.

It is a snub-nosed, slow-moving beast with webbed feet, scraggly fur, a naked, rat-like tail, and inch-long, orange buckteeth.

Unlike rats, nutria average 15 pounds, have plush, velvety pelts beneath their scraggly guard hairs, and are vegetarian.

But their diet is a danger to the marsh.

They have gnawed some areas down to circles of mud hundreds of acres across, said Greg Linscombe, a biologist with the state Department of Wildlife and Fisheries. They stymied a study to see if cypress plantings could reduce marsh erosion by gobbling all 100 seedlings within a few days.

“There are some areas where you can go out and see literally hundreds of animals,” Linscombe said. “It looks like a big pasture, except the whole thing is floating. And as far as you can see on the horizon, you see nutria.”

But, he said, it is almost impossible to measure overall nutria damage in the masses of vegetation known as “flotants” in French or, in English, “floats.”

“These floats are moving around. You almost have to do aerial photographs and measure land-water ratios over time to see if there is more water and less land,” Linscombe said.

Louisiana State University ecologist Charles Sasser is leading a small-scale study. Last summer he and a team of researchers caged in small areas of the flotant to keep nutria out, and will measure the plants inside and outside the barriers next spring.

The enclosed plants were already visibly taller in the fall, he said.

A similar study on ordinary marshland wound up with vast mud flats surrounding small enclosed stands of high marsh grass.

The nutria problem has its origins in Scandinavia where an overabundance of farmed minks reduced the demand for nutria pelts. A few cold winters in Europe might be enough to control the mink competition, at least for a while.

From about 20 years starting in 1962, more than 1 million nutria pelts a year were harvested in Louisiana--1.7 million one year in the late ‘70s, Linscombe said.

“During that entire time, you didn’t hear anything about marsh damage from nutria,” Linscombe said. “You didn’t hear anything until ‘85-’86,” Linscombe said.

Then, he said, the nutria market plummeted.

The main reasons were a fashion change from fur to leather, combined with seven very mild winters in northern Europe, and overproduction of ranch mink that made mink as cheap or cheaper than nutria, he said.

Some people put much of the blame on anti-fur protests by animal-rights activists. Linscombe said that may have played a part but was not a major factor.

About 6,000 to 7,000 trappers had to look for other income. The number of nutria trapped for their fur dropped to a couple of hundred thousand a year, he said.

“It looked like once we got below 500,000 to 600,000, we started seeing damage, and having damage reported by land companies,” he said.

Nutria are known as coypu in South America, their original habitat. But when the conquistadors saw them, they mistook them for otter and called them nutria--Spanish for otter. They also have been called the South American beaver, but are really their own kind of animal. Their scientific name, Myocastor coypus, reflects the similarity to beaver, which has the scientific genus Castor.

Tabasco creator E. A. McIlhenny brought nutria to Louisiana in 1937. He figured they could be farmed for their pelts. It was a reasonable idea--nutria are farmed today in Europe. The pelts are used for both felt and fur and the meat, called ragondin, is sold as a delicacy.

Removing the guard hairs, either by cutting or pulling them out, leaves a rich, velvety pelt. It is used more often as a lining than as an outer fur for coats.

“They were raised in tremendous numbers at one time in Poland--more mutation colors--whites, blacks, gun-metal gray,” Linscombe said.

McIlhenny’s plans went awry in the floods of ’39 and ’40. Nutria swam out of their pens and into the swamps. Their only predator there is the alligator and, because one female nutria can bear six to eight litters a year, they were fruitful beyond all imagining. Within two years, they had spread to Texas and Mississippi. More recently, they have been seen as far north as Virginia and the Midwest.

“The nutria denudes the marsh down to the soil, which is organic in nature. That may be just enough that the marsh cannot recover,” Linscombe said. “It’s an added factor that aggravates these other, more serious, conditions and may make the difference between the marsh continuing to be marsh or turning to open water.”

The state is looking at several ways to deal with the problem and the attendant coastal erosion.

Linscombe has traveled around North America and to Europe and the Far East to drum up interest in Louisiana furs. The Department of Wildlife and Fisheries is also trying to drum up interest in nutria meat with a Nutria Fest at the Louisiana Nature and Science Center in New Orleans.

The first Nutria Fest, last fall, attracted a few hundred people and a score of chefs with a nutria cooking contest judged by Paul Prudhomme. It was hard to tell what the meat would taste like on its own, but many of the recipes were tasty enough to those who were willing to eat them.

Others, like one veteran who had too many close encounters with rats in Vietnam, found themselves queasy at the thought of eating nutria, even though the Nature Center staff stressed that the critters are closer kin to the guinea pig than to the rat.

Some sort of bounty will be needed to encourage trapping, at least at first, Linscombe said.

“We have examined a lot of alternatives. We haven’t found any. We know what works, because it worked in the ‘60s. If you have 5,000 or 6,000 people out there and they have a reason to trap the nutria, your problem is eliminated.”