A Decade of Chasing a Fish Tail: Thwarted Recovery of Paiute Cutthroat Trout in California-What Have We Learned

Paiute cutthroat trout (Oncorhynchus clarkii seleniris) (PCT), a federally designated threatened species, are native to 19 km of Silver King Creek, in the northern Sierra Nevada mountain range of California, USA.  PCT evolved in isolation from other fish species.  Introduced rainbow trout O. mykiss and Lahontan cutthroat trout (O. c. henshawi) hybridized and displaced pure PCT in their native range, leaving only transplanted isolated headwater tributary populations.  Unauthorized plants of rainbow trout in headwater tributaries left PCT in only two small streams with a few hundred individuals.  The fish was originally listed as endangered in 1967 but reclassified as threatened in 1973 to facilitate management.  Chemical treatments have been successful in eliminating introgressed trout from headwater tributary populations.  Successful elimination of hybrid trout and the subsequent rebound of these PCT populations in headwater tributaries to serve as source populations have set the stage for restoration of PCT to their historic range in Silver King Creek.  U.S. Fish and Wildlife Service, U.S. Forest Service and California Department of Fish and Game began a project to implement this recovery action beginning in 2001.  The U.S. Fish and Wildlife Service Revised Recovery Plan (2004) for the Paiute Cutthroat Trout identified the elimination of nonnative trout from historic habitat in Silver King Creek as a Priority 1 recovery action.  Environmental groups opposed to the project have sued over environmental compliance issues and state and local agencies have refused to provide needed permits. The use of rotenone has become controversial with groups concerned with treatment impacts to non-target organisms and opposed to use of pesticides.  An update on the legal challenges and the PCT restoration effort are given.