8087

• UCREFRP Catalog Number: 8087
• Author: Valdez, R. A. and B. R. Cowdell.
• Title: Lake Powell Inflow Study. Annual Summary Report - 1994.
• USFW Year: 1994.
• USFW - Doc Type: 453-1,
• Copyright Material: NO

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sand shiners. One striped bass (117 mm 11..) had remains of 25 fish in its stomach (15 were identified as
shiners, ranging from 10 to 32 mm 11..). Another (86 mm 11..) had remains of approximately 30 fish with 8
identified as shiners (ranging from 8 to 15 mID 11.). A more detailed stomach content analysis will be
included in the final report.

5.4 SUMMARY OF ENDANGERED FISH CAPTURED

A summary of all threatened and endangered fish handled by BIO/WEST during this investigation is presented
in Appendix A

5.4.1 Colorado SQuawtish

A total of 82 Colorado squawfish were captured during 1994 sampling of the Lake Powell inflow. One
squawfish was an adult, 8 were juveniles, and 73 were age-O. One adult and one juvenile squawfish were
captured electrofishing, all other squawfish were captured with seines. The one adult Colorado squawfish was
captured in the Palmer Canyon are3 (RM 195.0) during pre-runoff sampling on 4120/94. This fish was a female
of 349 mm TL, and weight of 240 g, it was implanted with PIT-tag number 1FIF793COD.

During pre-runoff sampling a total of 69 age-O and 7 juvenile (> 70 mm 11..) Colorado squawfish were captured
seining, resulting in a geometric mean CPE of 1.12 (S.D. 3.86) fish/100m2. Average length of age-O squawfish
captured during pre-runoff sampling was 47.5 mm 11.. (range 31 - 68 mm 11..). The seven Juvenile squawfish
ranged from 71 to 83 mm 11.. A length frequency histogram for age-O and juvenile squawfish captured during
pre-runoff sampling is presented in Figure 3. During post-runoff sampling four age-O Colorado squawfish were
captured seining, resulting in a geometric mean CPE of 0.08 (S.D. 1.34) fish/100m2. These fish ranged from
29 to 52 mID 11- No juvenile squawfish were captured during post-runoff sampling.

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N = 76

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o 6 ...........
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LU
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~ 4 .......
u..

2 ..

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30 40 50 60 70 60 90
TOTAL LENGTH (mm)
Figure 2. Length frequency histogram for age-O and juvenile Colorado squav.1ish captured in the Lake Powell
inflow, April 1994.

5.4.2 Gila sp.

One Gila ~ me3Suring 45 mm n.. was captured seining at the mouth of Dark Canyon (RM 192.8) during
pre-runoff sampling. This chub was too small to identify to the species level. however dorsal and anal ray
counts were lalla (similar to modes reported for humpback chub and bonytail).

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