GLACIER NATIONAL PARK – The National Park Service is considering using “rotenone” to kill rainbow trout that were introduced to Gunsight Lake in the early 1900s. The species is displacing native cutthroat trout.
Rotenone is a pesticide, rat poison and fish toxin. The idea is to apply the toxin via boat and backpack sprayers to kill the non-native fish. Precautions would be taken to prevent it from spreading downstream by using a neutralizing agent. Once all the non-native fish are eradicated, the lake would be stocked with cutthroat trout.
Some critics say poison should not be used and other tactics are available including electrofishing. Park officials say they’ve tried other methods in the past, and they are too slow and have not worked, while rotenone is extremely effective and can be done within a week.
