Environmental Assessment for the Conservation of Native Westslope Cutthroat Trout in Camas Lake and Big Camas Creek by Mechanical Removal of Nonnative Yellowstone Cutthroat Trout
Feb 14, 2022 3:12 PM
Westslope cutthroat trout (WCT) have undergone substantial reductions in distribution and abundance throughout their native range in the upper Missouri River basin. Genetically unaltered WCT presently occupy 2.3% of their historic habitat within the Smith River watershed. WCT in the Smith River watershed face multiple threats including reduced distribution and abundance, stream and riparian habitat conditions, and spatial isolation; however, the single most significant threat to the long-term persistence of WCT is the presence of non-native trout. Since the late 1800’s, numerous nonnative fish species have been introduced throughout the Smith River watershed, and nonnative brook, brown, rainbow, Yellowstone cutthroat, and hybrid trout have become the dominant species in most streams historically occupied by WCT. Brook and brown trout displace WCT through competition or predation. Rainbow and Yellowstone cutthroat trout readily hybridize with WCT, resulting in populations entirely comprised of hybrid individuals (hybrid swarm) or mixed populations of hybrid and genetically unaltered fish. Currently, the most substantial remaining WCT populations are those isolated from nonnative species by natural or constructed barriers. Existing populations not protected by barriers have reduced distribution and densities or are irreversibly hybridized. The likelihood of long-term persistence of WCT populations not protected by barriers is low.
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Public Comment:
Accepted from February 14 thru March 16, 2022.
Written comment should be delivered to the following address:
Montana Fish, Wildlife & Parks
R-4 Fisheries
Big Camas Creek Westslope Cutthroat Trout Conservation
4600 Giant Springs Rd
Great Falls, MT 59405
or