The Utah Division of Wildlife Resources and the Ashley National Forest have plans to reintroduce the native Colorado cutthroat trout into a handful of areas in the High Uintas Wilderness and Uinta Mountains in northeastern Utah.
The environmental impact study is now open for public comment.
Habitat loss and breeding practices of the native cutthroat trout has caused a dramatic decline in their populations. After conducting an environmental impact study, wildlife biologists recommend some areas of the Uintas be treated with a piscicide —a substance poisonous to fish only—to kill off the invasive brook trout, allowing for the reintroduction of the native cutthroat.
The eastern brook trout was introduced to Utah streams in the middle of the 19th century. Trina Hedrick is the Northeastern Region Aquatics Manager for the Division of Wildlife Resources. She says, back then, native fishes were not valued, and there was no Endangered Species Act.
“There was a major round of stocking by the federal fish and game commission and then the states kind of jumped on board with the brook trout. And, it was simply to provide angling opportunities. We just weren’t concerned, right, with declining native fish populations. So, it was literally about people moving out west and sometimes even from Europe into America and people wanting to fish for the same fish they’ve always fished for.”
Rotenone is the treatment that will be used to kill off the fish in select areas in the Uintas. It’s a natural substance that derives from the roots of tropical plants in the pea family. Hedrick says biologists have been evaluating the situation for at least 20 years. She says the treatments are labor intensive and complicated because the treatment areas are remote.
“They basically analyzed drainages that needed to be or could be restored. So, you’re looking at things like, is there a barrier to prevent reinvasion by brook trout? Can you actually treat down to that barrier, restore that area above the barrier and protect that population into the future?
Hedrick says, ironically, the brook trout have done poorly in their native habitat in the eastern U.S. They’re more aggressive and outcompete the cutthroat in the western water systems.
We were the ones that actually put brook trout in a lot of different places. And they have done really well, really well, to the detriment of our native cutthroat trout. We’ve seen a major reduction in Colorado River cutthroat trout populations. And, we know it’s the right thing to do to start restoring the cutthroat trout populations.”
Hedrick says some anglers target the treatment areas for brook trout, but there are still many areas throughout the Uinta Mountains where they can be fished. Prior to 2022, when the treatments are scheduled to begin, they’ll conduct more studies and will look at all the species that would be impacted.
“It’ll be a couple hundred new lake acres restored and then we’ve got about, it’ll be about 40 to 50 stream miles restored, which is really awesome. It spans the Lake Fork drainage, the Rock Creek drainage and the Yellowstone drainage. Understanding how we’re going to get into these locations, where we’re going to station people.”
Once they release the chemical into the water, Hedrick says it takes about a week before they allow access and reintroduce the trout and other aquatic species.
“That does kill all fish that it will come in contact with. Trout are very susceptible to rotenone. And, it will also harm the bugs, the macro invertebrates that are still gill breathing in the water. And that is not ideal but that’s just what we have to deal with.”
A link to the Environmental Impact Statement https://www.fs.usda.gov/project/?project=31640 along with a slide show of the cutthroat trout can be found on KPCW.org.
If you have questions about the treatment, call the Division of Wildlife Resources Northeastern Region office at 435-781-9453.
Contact: Trina Hedrick, DWR Northeastern Region Aquatics Manager, 435-790-2283, or Tonya Kieffer-Selby, DWR Northeastern Region Conservation Outreach Manager, 801-995-2972
