Guided by the 2008 Mountain Lakes Fisheries Management Plan, the National Park Service has successfully removed non-native fish from mountain lakes using intensive gill netting and a piscicide (fish toxicant) known as “antimycin”, and is preparing to continue restoring other mountain lakes in North Cascades National Park. However, antimycin is no longer commercially available, and all stocks have been depleted. As a replacement, the NPS is proposing to use CFT Legumine™, a liquid formulation of rotenone, to remove fish from larger lakes in North Cascades National Park where methods such as gill netting are not feasible. Rotenone has been used successfully in several national parks including Yellowstone and Yosemite to restore aquatic ecosystems, and analyses by the Environmental Protection Agency and National Park Service indicate the piscicide has environmental effects similar to antimycin.
The purpose of these efforts is to restore these naturally fishless mountain lake ecosystems, which have been harmed by stocking of non-native fish that are now over-reproducing. Monitoring has shown that native species, such as long-toed salamanders and tailed frogs, are returning to these naturally fishless lakes following fish removal.
“Considering that we had not documented amphibians in many of these lakes prior to fish removal, it is a very exciting that these species are returning so quickly to their natural habitats once the fish are gone,” said North Cascades National Park Superintendent Karen Taylor-Goodrich. “It is rewarding to know that our actions now have the potential to restore these remote ecosystems to what they were prior to human stocking practices.”
North Cascades National Park is soliciting public comments during a 30-day public review period that extends through June 14, 2013. During this time, comments may be submitted online via the project website (www.parkplanning.nps.gov/restore_sourdough) or by regular mail to North Cascades National Park Complex Headquarters, 810 State Route 20, Sedro-Woolley, Washington, 98284.
Links to photos and “Frequently Asked Questions” may be found by following the same link (www.parkplanning.nps.gov/restore_sourdough) and clicking on “Open for Comment” then clicking on the link to the proposal and scrolling to the bottom of the page.