Isaac Aftermath: 'Swamp Rats' Die En Masse

Nutria Bodies

Dead nutria in Mississippi after Isaac

(Image credit: Mississippi Department of Environmental Quality)

Piles of nutria carcasses line beaches in Mississippi after Hurricane Isaac flooded the invasive rodents' marsh habitats.

Dead Nutria

Dead nutria on beach

(Image credit: WLOX)

Tens of thousands of drowned nutria have washed up on beaches in Mississippi after Hurricane Isaac.

Nutria Washed Ashore

Dead nutria in Mississippi after Isaac

(Image credit: Mississippi Department of Environmental Quality)

Clean-up crews are removing the rotting nutria carcasses with pitchforks and front-end loaders. The smell is reportedly terrible.

Dead Nutria

Nutria wash ashore after hurricane isaac

(Image credit: Mississippi Department of Environmental Quality)

Mississippi officials estimate that there could be as many as 20,000 dead nutria (several tons' worth) washing ashore.

Nutria Family

nutria in a national park in France

(Image credit: southmind, Shutterstockr)

Also called coypu, nutria (Myocastor coypus) were introduced to every continent except Antarctica and Australia from South America, according to the USGS. Though the semi-aquatic rodents are viewed as pests by many, as they destroy large swaths of marsh vegetation and crops, they are valued for their fur in some regions. It was partly this interest in their fur that led to their spread throughout the world.

Nutria

A portrait of a nutria showing its orange-red teeth

(Image credit: Eduard Kyslynskyy, Shutterstock)

Weighing on average 12 to 15 pounds (though they can get as large as 20 pounds), nutria are like giant rats. They sport large front teeth and forepaws with four clawed toes and a non-functional toe; their hind feet are tipped with 5 clawed toes, four of which are webbed to help the rodents move through their watery homes.

Nutria Corpses

Nutria wash ashore after hurricane isaac

(Image credit: Mississippi Department of Environmental Quality)

Nutria corpses dot the shoreline in this image from a Mississippi Department of Environmental Quality field worker.

Dead Nutria

Nutria wash ashore after hurricane isaac

(Image credit: Mississippi Department of Environmental Quality)

Officials expect more nutria to wash ashore in the next several days.

Dead Nutria

Nutria wash ashore after hurricane isaac

(Image credit: Mississippi Department of Environmental Quality)

Nutria are invasive species that live in marshlands along the Gulf Coast.

Stephanie Pappas
Live Science Contributor

Stephanie Pappas is a contributing writer for Live Science, covering topics ranging from geoscience to archaeology to the human brain and behavior. She was previously a senior writer for Live Science but is now a freelancer based in Denver, Colorado, and regularly contributes to Scientific American and The Monitor, the monthly magazine of the American Psychological Association. Stephanie received a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science communication from the University of California, Santa Cruz.