1. ISDA quagga mussel detail

The Idaho State Department of Agriculture has reopened a section of the Snake River near Twin Falls following treatment for invasive quagga mussels.

State wildlife officials also reopened the section for hunters and anglers.

Quagga mussels can clog irrigation and municipal water systems, outcompete native organisms and degrade water quality.

State agriculture investigators in September found an adult mussel and veligers, or larvae, during routine monitoring. The department closed part of the river, and the state Fish and Game Commission closed access on the same river segment for hunting, fishing and trapping. ISDA led a multi-agency eradication effort along 6 miles of the river on Oct. 3-13.

Water access was reopened Dec. 18 between Broken Bridge-Yingst Grade and Pillar Falls, during Centennial Waterfront Park operating hours, according to a news release from ISDA. Watercraft — and waders, life jackets, decoys and fishing tackle — entering or exiting the river must be decontaminated at a free station at the park.

“We need everyone to step up and take personal responsibility to make sure their watercraft and equipment are thoroughly decontaminated if they choose to recreate in the area below Pillar Falls,” Craig White, who supervises Fish and Game’s Magic Valley region, said in a release. “Knowing there are folks looking to access the river to hunt, fish, or trap, we expect them to follow the clean, drain dry process to reduce any chance of quagga mussels being spread to other water bodies in Idaho.

Access remains closed from Pillar Falls upstream to Twin Falls Dam, according to the Department of Agriculture.

Initial sample results indicated that the copper-based treatment was successful, but it is too early to conclude that complete eradication occurred, according to the ISDA release.

Quagga mussels generally stop reproducing when water temperature drops below 57 Fahrenheit and sampling is slated to resume in spring.

Copper levels have dissipated, and the department is not detecting any additional copper.

The agriculture department has not determined how the adult quagga mussel and the larvae got into the river, public information officer Sydney Kennedy said.