FERC Project No. 2079 - PCWA Middle Fork American River Project ...

Application for New License Middle Fork American River Project (FERC Project No. 2079)
Nonnative bullfrogs and smallmouth bass, potential predators of FYLF, were only
observed in the comparison river study site in the lower North Fork American River
upstream and downstream of Lake Clementine. This reach was the warmest in the
study area. Bullfrogs and smallmouth bass were not observed in the cooler river
reaches associated with the MFP. These predatory species may be a factor in the
apparent absence of FYLF below Lake Clementine (not a part of the MFP). In the
bypass and peaking reaches associated with the MFP, nonnative brown trout and
crayfish were observed at several locations. Native aquatic garter snakes, a known
predator of FYLF, were present throughout the study area. The presence of native and
nonnative predators may limit reproductive success for FYLF and, thus, may decrease
the quality of suitable breeding and rearing habitat in the study area, but the magnitude
or importance of the relationship is uncertain.
Cold water temperatures and fluctuating flows can limit the suitability of breeding and
rearing habitat (Jones et al. 2005; Kupferberg et al. 2007) of FYLF. Cold water
temperatures (e.g.,