Fish and Game to monitor impacts to fisheries from quagga mussel treatment

Quagga mussels have once again been detected in the Snake River near Twin Falls. The new detections were a result of extensive proactive monitoring done by the Idaho State Department of Agriculture (ISDA), the state agency responsible for invasive species monitoring and management.

While ISDA detected fewer mussels in 2024 than in 2023, the second treatment to eradicate mussels is a critical step to stop further spread.

ISDA is planning another chelated copper treatment, slated to begin during the week of October 7, 2024.

Using experience gained from the 2023 treatment, Fish and Game fisheries biologists are preparing for additional fish mortality throughout the treatment area, especially in the section of river upstream of the Twin Falls power plant that was not treated in 2023.

Pre-treatment surveys

Prior to the treatment, Fish and Game fisheries biologists have conducted pre-treatment surveys in the river, upstream of the Twin Falls power plant, to collect fish community composition and biological data within the reservoir section of the new treatment area.