Biologists to finalize Montana cutthroat trout strategy
Laura Lundquist
(Missoula Current) Montana’s cutthroat trout are on the decline, but fisheries biologists are developing plans to preserve the species, especially those that still migrate through the streams of western Montana.
For the past two years, Kristen Cook has held so many meetings with biologists, anglers and watershed specialists in southwestern and western Montana that she has everyone’s dietary restrictions memorized. But as Fish, Wildlife & Parks’ cold-water species coordinator, she’s needed a lot of input in order to develop conservation strategies to preserve Yellowstone cutthroat trout in the Yellowstone River basin and westslope or black-spotted cutthroat trout in the Columbia River basin. But there’s still a bit more to do.
“For westslope cutthroat west of the Divide, there is risk to those populations of hybridization. Whether or not that risk is realized might depend on whether or not there’s intervention. And if we want to do something about this, we need to do it now, while we still have migratory fish on the landscape and cutthroat are still widespread,” Cook told a Montana Trout Unlimited crowd in April.
As Montana enters another summer of drought, low streamflow and predicted heat waves, its native trout are in trouble, because native species need colder, cleaner water than nonnative species such as rainbow and brown trout. Bull trout and arctic grayling are native species that are closer to going extinct so they get more attention. But cutthroat trout face their own threats.
Anglers have long enjoyed catching cutthroat trout in the streams of three major river basins: the Missouri, Yellowstone and Columbia. They thrill to feeling the tug on the line and seeing the flash of red under the throat and along the gills of a cutthroat as it rises in the water. But anglers noticed that opportunity became less common, and some tried to get Endangered Species Act protection for cutthroat in the mid-1990s.
“From 1999 to 2007, as biologists surveyed more populations, they learned that populations were not as robust as we previously thought and more hybridized,” Cooke said.
FWP stocked trout, including nonnative rainbow trout, in lakes and streams until 1974 when fisheries biologist Dick Vincent showed stocking harmed wild trout populations. Stocking added to competition, and rainbow trout hybridize with cutthroat trout, watering down historic genetic adaptations of cutthroat and reducing species fitness. Eventually, the rainbows and rainbow hybrids or “cutbows” wipe out the native trout.
The westslope cutthroat in the Missouri River basin were the worst-off because there were just a few small, isolated populations. So they would need to be isolated from nonnative trout and allowed to expand.
In 2007, FWP developed a statewide conservation agreement and a memorandum of understanding with the primary goal of ensuring self-sustaining cutthroat persistence and requiring FWP to create conservation strategies for the three major river basins. But the only strategy that resulted was for the Missouri.
“We didn’t follow through on that commitment because that agreement was really targeted to the Missouri where cutthroat were imperiled,” Cook said. “The solution of what to do for cutthroat in the Yellowstone and Columbia drainages is not straightforward, and the complexities in these major river basins were not addressed in the MOU.”
A few years ago, Cook and other fisheries biologists decided to remedy that because they are running out of time. Long-term drought and high water temperatures take their toll on cutthroat populations every summer while nonnative trout are less affected. Studies showed that the extent of hybridization is increasing in the Flathead River while cutthroat abundance is declining in the Yellowstone River.
Meanwhile, FWP was spending a lot of money on isolated projects to conserve cutthroat trout, but the effort tended to be scattershot. Finally, the Columbia and Yellowstone drainages contain populations of migratory cutthroat - an imperiled cohort that move to other locations to spawn rather than remaining in one stretch all their lives. For that reason, migratory trout tend to be bigger so they’re popular with sportsmen.
Hybridization can eliminate the migratory trait, but how do you keep a migratory population from encountering rainbow trout in their travels? Plus, you don’t want to use barriers that might impede other migratory species such as bull trout.
Those are some of the challenges biologists have been working on for the past two years while they’ve been inventorying every tributary with cutthroat. They’re now close to finalizing the two new conservation strategies, which will use different techniques to protect migratory and isolated, nonmigratory populations. In watersheds with healthier cutthroat populations that are widespread and abundant, the focus will be on migrating populations. In watersheds where cutthroat are more scarce, biologists will use the Missouri River approach and try to improve the population resiliency by expanding the distribution.
But migratory fish are the priority for conservation.
“There’s no silver bullet when it comes to conserving migratory fish. But if we lose them, we lose them forever,” Cook said. “FWP has been waiting for tools to come along that are better than the tools we have now. But we don’t want to wait until there are no migratory fish and we have tools available. So it might come down to using the tools we have in a different way, or applying them on a larger scale. So we’ve started having those conversations with our partners.”
Cook said strategies have been selected for all nine watersheds in the Yellowstone basin as of this spring. She used the upper Yellowstone River as an example. The migratory cutthroat in the upper section are more viable, so the strategy would conserve the migratory fish and increase their numbers. In the lower stretch, migratory trout are rare and most populations are at-risk, so biologists will secure only the strongest populations.
Region 2 fisheries biologist David Schmetterling said it’s been complex and challenging to develop such innovative strategies, but the first drafts have already garnered a lot of compliments.
“For example, Idaho, who's in the same position but hasn’t drafted a strategy, wants to use ours as a basis for theirs. An adaptation of it is also being considered for a bull trout conservation strategy, and it's all because of a tremendous amount of work and dedication from Kristen Cook,” Schmetterling said.
Strategies for the Columbia basin watersheds will be finalized next winter. The work has taken some time, because funding comes mainly from the U.S. Fish and Wildlife Service state wildlife grants, which were greatly diminished last year due to Congressional cuts. They’ve also received some money from the U.S. Sportfish Restoration Program.
“We’re in the last stage of developing watershed-specific plans, which house the actions we need to achieve these targets,” Cook said. “This is more than just a plan. This is a means of conserving Montana’s state fish, the black-spotted cutthroat. As stewards of the resource, we have a responsibility to cutthroat, to anglers and to future generations.”
Contact reporter Laura Lundquist at lundquist@missoulacurrent.com.