So far, Idaho authorities have not discovered any more invasive quagga mussels • Oregon Capital Chronicle
Since resuming water sampling this spring, state officials have not detected any viable quagga mussels, said Chanel Tewalt, director of the Idaho Department of Agriculture.
On September 19, 2023, the Idaho Department of Agriculture announced that it had discovered invasive, non-native quagga mussel larvae in water samples from the Snake River near Shoshone Falls and Centennial Waterfront Park in Twin Falls.
As the Idaho Capital Sun previously reported, state authorities applied a copper-based chemical called Natrix to a 16-mile stretch of the Snake River from Oct. 3 to 13 to kill the mussels.
But state authorities had to wait through the winter and spring until water temperatures were high enough to resume sampling and find out if the mussels had been killed and the outbreak stopped.
“We have not detected any viable mussels,” Tewalt said in a telephone interview. “But we know from data and experience in other states that we need to take samples during the current peak reproductive season.”
The mussels can multiply rapidly, cover boat hulls, clog pipes and pose a threat to drinking water, agriculture, recreational tourism and energy production, government officials said.
New watercraft rules
As part of its mussel control efforts, the Department of Agriculture has expanded its water sampling program and increased the number of watercraft inspection and decontamination stations by creating two new positions and using $6.6 million in funding approved by the Idaho State Legislature earlier this year.
According to the Idaho Department of Agriculture, the state had conducted more than 115,000 watercraft inspections as of Monday afternoon.
This year also brings new rules for watercraft inspection. First, all out-of-state watercraft must be inspected and decontaminated at a watercraft inspection station before entering Idaho waters, according to the Idaho Department of Agriculture.
Second, in the Snake River between Broken Bridge and Pillar Falls, all watercraft and transportation equipment (such as waders, waders or life jackets) must be decontaminated before entering and after exiting the water in this section of the river.
To decontaminate watercraft, technicians at watercraft inspection stations offer free hot water washes, during which they hose down, clean and dry the boats, says Nic Zurfluh, chief of the Idaho Department of Agriculture’s Office of Invasive Species.
The state’s overall message is “clean, drain and dry,” and officials encourage boaters and recreational users to participate in the program to protect Idaho’s waters from the invasive mussels and extend the life of their boats.
Zurfluh said any boater can help themselves by using a “clean, drain and dry” strategy, even if they are not required to visit an inspection/decontamination station.
“If a boater can clean their equipment — remove all aquatic plants, debris, mud, things like that — clean everything out, drain all the compartments, remove the plugs … make sure to drain all the raw water and let the boat dry thoroughly between trips, that’s very important, especially when they’re traveling between bodies of water or watersheds, different river systems, and long distances,” Zurfluh said in an interview at Centennial Waterfront Park’s inspection/decontamination station. “And it’s not just quagga mussels (that we’re trying to stop). There are other aquatic invasive species, other fish pathogens that we’re concerned about.”
Zurfluh said inspecting and decontaminating the watercraft is an important part of stopping the mussel spread. He said so far this year, state inspection stations in Idaho have discovered 17 mussel-contaminated boats before they were launched. But Zurfluh said state officials now know that responding to quagga mussels is a marathon, not a sprint, when it comes to monitoring the health of the Snake River and fighting invasive species.
“We are becoming more efficient with our inspection/decontamination process here at Centennial Park, but it will take several years of extensive monitoring before we know for sure … whether the treatment was effective or if additional treatment is needed,” Zurfluh said.
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Idaho Capital Sun, like Oregon Capital Chronicle, is part of States Newsroom, a nonprofit news network supported by grants and a coalition of donors as a 501c(3) nonprofit organization. Idaho Capital Sun maintains its editorial independence. If you have any questions, please contact Editor Christina Lords: (email protected). Follow Idaho Capital Sun on Facebook and X.
