A large, fast-breeding rodent that is ravaging wetlands and crops has alarmed Solano County officials and farmers.

The coypu, which can grow up to 2 feet long and weigh 20 pounds, was discovered in the Central Valley as early as 2017, after remaining undetected for 40 years in California. But recently they have multiplied.

The state’s fish and wildlife efforts captured a total of 5,171 coypu in 10 counties, including Stanislaus, Fresno, San Joaquin, Mariposa, Sacramento, Contra Costa, Madera, Tuolumne and Solano.

The fear is that they will migrate to other areas of the North Bay beyond the Suisun Swamp, particularly to sensitive wetlands and watersheds, such as the Napa-Sonoma Swamp Wildlife Refuges, the Napa-Sonoma Swamp National Wildlife Refuge, San Pablo and San Francisco Bay.

The species could cause damage costing $1 billion to the regional economy, Solano County supervisors estimated in an Oct. 25 letter to members of Congress.

There is concern that the rodent could jeopardize the levees of the Sacramento-San Joaquin River Delta, which constitute the state’s critical water infrastructure. The wetlands where they thrive are essential to the region’s ecosystem.

“They have the greatest impact on irrigation systems. There’s nothing good about that,” Solano County Agriculture Commissioner Ed King told the Business Journal.

Lisa Shipley, county director of the Solano County Farm Bureau, echoes King’s concerns.

“They eat everything, and they eat a lot,” she says.

As a herbivore, the coypu can eat a quarter of its body weight each day. They burrow into banks and levees, creating dens as deep as about 20 feet. And once they’re settled in, there’s another problem.

“It’s hard to get rid of,” Shipley said.

Additionally, females can produce up to three litters with up to 13 young over a 13-month period.

Against this backdrop, state wildlife officials sent teams of at least 40 people, including dog teams, to track down and trap the creatures in order to euthanize them.

The state has also installed 1,500 cameras, nearly a third of them in Solano County.

“We have a window of opportunity to eradicate the nutria population,” state spokeswoman Krysten Kellum said.

Meanwhile, Solano County has requested federal support to bolster California’s efforts to eradicate this invasive wetland pest. Native to South America, the species has caused problems in 17 states, including the Chesapeake Bay and Louisiana.

The Coypu Eradication and Control Act authorizes the U.S. Secretary of the Interior to provide financial assistance to states for the purpose of restoring marshes and other areas they have damaged. It authorizes $12 million between 2021 and 2025.

“The existence and spread of coypu in California will result in substantial ecological and economic impacts, including loss of wetlands and riparian habitats, soil and streambank erosion, levee failure, agricultural losses, degradation of wildlife and fish habitats, damaged revegetation sites and exacerbated spread. invasive plants,” read the October letter signed by Solona County Supervisor Mitch Mashburn, chairman of the board.

Susan Wood covers agriculture, law, cannabis, manufacturing, transportation, and banking and finance. She can be reached at 530-545-8662 or [email protected]