By Tucker Harris
Montana Fish, Wildlife and Parks plans to continue their multi-phase project to remove nonnative fish from southwest Montana’s North Fork of Spanish Creek as well as Chiquita and Big Brother lakes. The project will take place between Aug. 10 and Aug. 21 with the goal of restoring westslope cutthroat trout populations in the targeted areas.
Westslope cutthroat trout are native to Montana, however, over time the species has experienced a substantial decline in their population as a result of both habitat degradation and hybridization with nonnative species such as rainbow trout.
According to Montana FWP Information and Education Program Manager, Morgan Jacobsen, “[T]his project, restoring westslope cutthroat trout to the North Fork of Spanish creek, will eventually more than double the number of stream miles that are now occupied by westslope cutthroat trout in the Gallatin River drainage.”
The project will start by introducing Rotenone piscicide, a natural substance derived from the root of plants, into the waters to poison and kill all of the fish. Rotenone is selective in that it primarily effects gill-breathing animals, and therefore poses no significant risks to humans or other wildlife if consumed. Nonetheless, officials still caution people to avoid consuming water in the designated areas until the project is complete.
This is the second round of Rotenone treatments in the targeted areas, with the first dosage introduced in late August 2019. This second Rotenone treatment will ultimately guarantee the sites are free of non-native species and ready for westslope cutthroat trout to be reintroduced.
Rotenone naturally breaks down within 24 hours making it no longer active. With a detox station at the base of the treatment area, everything downstream of the project will see no change nor added risks for the public or wildlife’s consumption of water throughout the duration of the treatment.
“This is a big, positive step forward for westslope cutthroat trout restoration in Southwest Montana. We are excited for the opportunity to reintroduce westslope cutthroat trout back into the area,” said Jacobsen.