7400

• UCREFRP Catalog Number: 7400
• Author: Valdez, R. A.
• Title: The Endangered Fish of Cataract Canyon
• USFW Year: 1990.
• USFW - Doc Type: Final Report.
• Copyright Material: NO

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UST OF FIGURES
(Continued)

Number

Page

Figure 15. Species associations between humpback chub and selected native and
non-native species within four selected habitats. . . . . . . . . . . . . . . . . . . . . . . . . . .. 46

Figure 16. Dist.ribution of YOY Colorado squawfish by region, 1985-1988. . . . . . . . . . . . . . . . ., 50

Figure 17-. Frequency of back-calculated hatching dates for YOY Colorado squawfish
compared to river temperature and flow of the Green River, Colorado River,
and Cataract Canyon, 1985-1988. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 53

Figure 18. Mean total length (sample size) of YOY Colorado squawfish from the lower
50 miles of the Green River in four successive year classes. .................. 55

Figure 19. Longitudinal distribution by age category of humpback, bonytail, roundtail, and
unclassified chubs in Cataract Canyon (RM 200.0 to 216.5), 1985-1988. ......... 57

Figure 20. Principal components analysis of Cataract Canyon Gila showing the four
clust.ers of maximum membership; analysis of principal components 1 vs. principal

components 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 58

Figure 21. Growth of humpback and bonytail chub from Cataract Canyon, compared to
bonytail chub from the Green River (Vanicek 1967). ........................ 65

Figure 22. Monthly length-frequency hist.ograms for YOY chubs (Gila spp.) in the
Cataract Canyon Study Area for 1985-1988. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 67

Figure 23. Gradient of a 4-mile reach of the Lake Powell Inflow, with maximum
recorded lake elevation, minimum observed elevation for this study, and
range of levels that produced the maximum number of backwaters. . . . . . . . . . . . .. 73

Figure 24. Levels of Lake Powell from June to October, 1987 and 1988, that produced
the maximum number of backwaters in a 2-mile reach (RM 201.8 to 199.8) of inflow. . 74

Figure 25. CPE for adult Colorado squawfish in the five study regions for 1985-1988,
expressed as number of fish per 10 hours of electrofishing. .................. 81

Figure 26. CPE for adult Colorado squawfish in the fIVe study regions for 1985-1988,
expressed as number of fish per 100 feet of net per 100 hours ............... 81

Figure 27. CPE for YOY Colorado squawfish in the five study regions for 1985-1988,
expressed as number of fish per 100 m2 seined. .......................... 83

Figure 28. CPE for juvenile Colorado squawfish in the five study regions for 1985-1988,
expressed as number of fish per 10 hours of electrofishing. .................. 83

Figure 29. CPE for adult humpback chub in the five st.udy regions for 1985-1988,
expressed as number of fish per 10 hours of electrofishing. .................. 84

Figure 30. CPE for adult humpback chub in the five study regions for 1985-1988,
expressed as number of fish per 100 feet of net per 100 hours ............... 84

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