The Idaho State Department of Agriculture (ISDA) has announced a targeted quagga mussel treatment set to begin Tuesday, aiming to eradicate the small population of the invasive species in the Snake River.
Tuesday October 8, ISDA and contractors will launch a 10-day comprehensive treatment from downriver of Hansen Bridge to Centennial Waterfront Park.
The treatment product is the same product used to treat the Snake River in 2023, a copper-based product called, Natrix. The 2023 Natrix treatment significantly reduced the quagga mussel population in the Snake River.
The upcoming treatment is the first of the multi-faceted treatment plan. ISDA is planning a second treatment in November to target quagga mussels in still water and deep pool sections of the river.
“This treatment plan reflects Idaho’s commitment to using every available tool to combat this threat,” said ISDA Director Chanel Tewalt. “By combining targeted treatments with ongoing monitoring, we are maximizing our efforts with the ultimate goal of eradication.”
Natrix is labeled and approved by the Environmental Protection Agency for these kinds of aquatic applications. The treatment is being applied at one part per million, a rate intended to eradicate mussels but is below the drinking water standard for humans. The copper-based treatment application is occurring across an eight-mile section, less than one percent of the Snake River.
River access from Hansen Bridge to Yingst Grade is closed. It is not required by product label, but out of an abundance of caution to minimize exposure, ISDA advises the public to stay out of the dissipation area, from Hansen Bridge to Kanaka Rapid.
The treatment is expected to dissipate to normal river copper levels eighteen miles downriver at Kanaka Rapid. ISDA and the Idaho Department of Environmental Quality will routinely monitor the river from downriver of Hansen Bridge to Kanaka Rapid to evaluate treatment effectiveness and copper dissipation.
ISDA confirmed Tuesday September 24, 2024, a small number of quagga mussels in multiple samples in the Twin Falls area of the Snake River.
Quagga mussels spread rapidly and clog pipes that deliver water for drinking, energy, agriculture, recreation, and a variety of other uses. Established quagga mussel infestations have major impacts on fish populations, wildlife habitat and damage infrastructure so severely costing hundreds of millions of dollars in actual and indirect costs.
Quagga mussels were first identified in the Snake River near Twin Falls in September 2023. The ISDA implemented a treatment with a chelated copper product, the first treatment of this type and scale ever attempted in North America.
ISDA is the leading authority for the Snake River quagga mussel treatment. For more information, please visit idaho.gov/quagga.
