8290

• UCREFRP Catalog Number: 8290
• Author: Day, K. S. and C. Crosby.
• Title: An Assessment of Young-of-the-Year Colorado Squawfish ‎(Ptychocheilus lucius)‎ Use of Backwater Habitats in the Green River, Utah.
• USFW Year: 1997.
• USFW - Doc Type: FG-33,
• Copyright Material: NO

increased to a range from 13% to 25%. However, error rates for classification
backwaters alone were almost always lower than for Colorado squawfish backwate
of up to 80% were observed for Colorado squawfish backwaters, with most greate
Backwaters not used by Colorado squawfish were incorrectly classified 12% of t
Some examples of discriminant modeling are presented in Appendix A.
Fish Community and Catch-per-unit-effort
Catch-per-unit effort (CPUE; fish/100m3) for Colorado squawfish was gene
in summer and lowest in spring (Table 7). Suppositions that catch rate was in
run-off flows could not be substantiated. Although a negative relationship ex
CPUE and volume of peak flow, date of peak flow and duration of peak flow; the
were not very strong (R2<0.61) and were not significant (p>0.15) (Figure 5).
correlation analyses indicated no relationships (p>0.15) between flow paramete
Colorado squawfish (Table 8).
Twelve species of fish were caught in backwaters in addition to Colorado
native and eight non-native (Table 9). Red shiner (Notropis Iutrensis) was th
species. This fish was found in 91% (n=945) of all samples. CPUE for this sp
surpassed CPUE for any other species. The second most common species was fath
(Pimephales promelus). This species was present in 70% of all sites. Sand sh
Stramineus) was present in 51% (n=535) of all backwaters. During the period 1
shiners were common in samples, but they increased in abundance and distributi