Preservation of bull trout in Glacier National Park

Project Title: Preservation of bull trout in Glacier National Park: Experimental suppression of invasive lake trout in the Quartz Lake system

Populations of bull trout Salvelinus confluentus have dramatically declined throughout much of their native range over the past century. Consequently, the bull trout was listed as a threatened species under the U.S. Endangered Species Act in June of 1998. Bull trout declines are largely attributed to introductions of nonnative species, and habitat degradation and fragmentation. Glacier National Park (GNP) supports approximately one-third of the remaining natural habitat supporting the migratory life history of bull trout in the entire Columbia River Basin. However, after 14,000 years of dominance, Glacier’s greatest native aquatic predator is at high risk of extinction in several lakes along the western slopes of the Continental Divide. The decline of bull trout in GNP is directly attributed to the invasion and establishment of nonnative lake trout Salvelinus namaycush, which consistently displace bull trout in systems where they have been introduced. The overall goal of this project is to protect GNP's ecologically unique bull trout populations from further declines and potential extinction. Specifically, this collaborative USGS and NPS research project will assess demographics of the expanding lake trout population, and use this information to inform and implement experimental removal and control alternatives to reduce or eliminate competitive interactions in the Quartz Lake system and other lakes in GNP. This information is critical to understanding the feasibility of suppressing nonnative lake trout in a small, recently invaded lake that contains native bull trout. Results will be applied to management of other lakes in GNP and possibly other systems throughout the native range of bull trout.

l Information Sheet l

For more information contact:
Clint Muhlfeld
406-888-7926
cmuhlfeld@usgs.gov