Paiute Cutthroat Trout Restoration in California- a Long Road to Recovery

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 are one of the rarest trout forms in North America and 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 at the brink of extinction in their historic basin with only two small streams with a few hundred individuals.  Decades of restoration efforts and chemical treatments have restored PCT in headwater tributaries and have set the stage for restoration of PCT to their historic range in Silver King Creek using chemical treatments.  Chemical treatments are controversial in California, and have resulted in delays from litigation and extensive water quality monitoring.  Our paper discusses the history of this restoration and details the current chemical treatment (2013–2015) by the California Department Fish and Wildlife, USFWS, and USFS to remove non-native trout and restore PCT.