Nutria is an invasive, non-native semi-aquatic rodent species and was reported along the west shore of the Long Lake north basin near the boat launch on Feb 5, 2023, by Sylvia Robert. Another known sighting recently occurred on the west shore of the channel between the north and south basins. You can report a sighting at WDFW Siting Report. Make sure to take a photograph, geo-tag the location, and leave your preferred method of contact so the WDFW Aquatic Invasive Species Unit may reach you with questions.
Increased Nutria populations harm native ecosystems, impact landscapes, and increase disease transmission. Nutria damage is evident to varying degrees including but not limited to borrowing, undermining native vegetation and associated wetlands, and landscape plantings. Nutria reproduces rapidly, bearing multiple litters yearly. A single pair can produce over 15,000 offspring in a period of 3 years.
Nutria has visible large front teeth that are yellow to orange in color. Adults weigh 15 to 20 pounds for adults, this is about one-third the size of an adult beaver (>45 pounds) and 5-8 times larger than an adult muskrat (2-4 pounds). Smaller than a beaver but larger than a muskrat, the nutria is often mistaken for both. The flattened tail of the beaver is an obvious difference. Muskrat tails are laterally compressed, and their nose is of a more pointed shape than the blunt nutria nose.
Nutria also can impact public health and safety. The rodents can serve as hosts for several pathogens, including tuberculosis and septicemia, which can infect people, pets, and livestock. In addition, nutria can carry parasites, such as blood flukes, tapeworms, and liver flukes and a nematode known to cause a rash called “nutria itch.” Many of these organisms— found in nutria feces and urine—can contaminate drinking water supplies and swimming areas.
There are a few different options for managing the nutria population:
One option would be to trap the animal, here is a link providing more information about how to go about trapping and what to do after you've caught an animal: https://wdfw.wa.gov/species-habitats/living/nuisance-wildlife/trapping
Or contact a WDFW-certified Wildlife Control Operator, you can get more information with this link: https://wdfw.wa.gov/species-habitats/living/nuisance-wildlife/wildlife-control-operatorOutside of trapping the animal, there are some other methods that could be put in place to help deter the animal from entering your property:
You can visit this link: https://wdfw.wa.gov/species-habitats/invasive/myocastor-coypus#conflict under “Preventing Conflict” tab to find out more about non-removal methods
2/23/2023 UPDATE from Rachel Flannery:
Knowing Washington State has a population of Nutria, there are crucial benefits to the continued reporting efforts of Nutria sightings. It’s important to keep reporting to confirm that Nutria are still present and have not perished due to predators, humans, or climate. Sightings assist the Department with management and possible funding. Additionally, positive sighting reports help document the detection and distribution of AIS, such as Nutria, throughout Washington State and the data is provided to the United States Geological Survey for a national database at the end of each year.
If you have any further questions, please do not hesitate to write or call:
Rachel Flannery
Aquatic Invasive Species Unit
Washington Department of Fish & Wildlife
888.WDFW.AIS (888.933.9247)
Other sources:
Nutria Factsheet - An Invasive Rodent, April 2020
Watch a 4:51 US Fish and Wildlife Service video by clicking; Following the Invasive Nutria in the Northwest.