TWIN FALLS, Idaho — The mortality for sturgeon, pike minnow, largescale suckers and perch was near 100% after a 6 mile section of the Snake River was treated with copper chelate to eradicate quagga mussels in October. Sportfish species such as largemouth bass, bluegill and green sunfish numbers appeared largely unaffected by the treatment
- The Idaho Department of Fish and Gamereported on Monday that the post-treatment fish survey showed which species were impacted.
- Sturgeon mortality was near 100%. The sturgeon in the affected area were all stocked fish, with about 50% being from the 1990s, and 50% being within the last several years.
- Fish and Game will plan on restoring sturgeon populations once the Idaho State Department of Agriculture deems the river safe from the quagga mussel invasion.
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(Below is the transcript from the broadcast story)
By his estimation, Dennis Brauer has fished the waters of the magic valley for over 60 years.
Dennis Brauer: "I'm not against throwing a lure every once in a while, but I figure, I can catch fish, I can catch the same fish on a fly that you can on a lure or with bait, to me it's just more fun."
I wanted to find out what Dennis thought about the impacts on the snake river fish populations, as a result of the treatment for invasive quagga mussels.
Dennis Brauer: "All the other states, Montana Wyoming they're all in the same boat we are, they've got to try and keep this. And if it spreads … you know, it's not just for the fishery. It's for agriculture, Idaho Power, they're a pretty nasty mollusk no doubt."
Idaho Department of Fish and Game reported on Monday that the treatment to eradicate the quagga mussels in the snake river caused a high mortality in some fish species.
Mike Peterson: "The only fish that we were seeing during the mortality again were those large scale suckers, the northern pike minnow, the yellow perch and the white sturgeon."
The chelated copper treatment to the six-mile stretch in October was expected to kill many of the species in the impacted area, but after post-treatment surveys, fish and game found that some species fared pretty well.
Mike Peterson: "We identified that basically the game fish, the largemouth bass, the bluegill; and the sunfish were essentially in impacted by the treatment."
Throughout the two-week treatment, fish and game handled almost seven tons of dead fish.
Five tons were largescale suckers, and one ton was comprised of common carp and northern pikeminnow. Many of these fish are expected to repopulate the snake naturally.
As far as sturgeon in the treatment area, it is believed they suffered a 100% mortality rate.
Mike Peterson: "The main piece of the fishery that we'll have to rebuild is the white sturgeon component."
All of the sturgeon were stocked fish, some had been stocked as early as the 1990s, while others had been stocked as recently as 2021.
Before doing any stocking activities, fish and game will wait for word from the department of agriculture on how successful the quagga treatment was, and what their next steps may be.
Dennis Brauer: "Like I say, don't worry, worry, be concerned, but the fishing, it didn't kill all the fish in the water, the fishing's gonna come back. The only thing it's gonna affect is maybe sturgeon fishing, but you can go downstream, there's still a lot of sturgeon downstream."
