7608

• UCREFRP Catalog Number: 7608
• Author: Masslich, W. J.
• Title: City of Craig, Colorado, Yampa River Diversion Fish Passage Study
• USFW Year: 1993.
• USFW - Doc Type: Final Report.
• Copyright Material: NO

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SUMMARY OF FINDINGS
1. No Colorado squawfish or other endangered species were captured during this study.
2. A total of 20 species of fish including six native and 12 non-native species were handled during
the study. Six hybrid combinations of native and non-native sucker species were also handled.
3. A total of 1,344 fish representing 11 species and five hybrids were tagged during the study.
4. A total of 265 fish, representing seven species were recaptured during the investigation resulting
in an overall recapture rate of approximately 19.7%.
5. Twenty-eight fish representing six species were documented moving over the diversion structure
during the study; 21 passing in an upstream direction and seven passing in a downstream
direction. Three of the 28 fish were northern pike tracked using radiotelemetry and the
remaining 25 were marked with Floy or PI'T tags and subsequently and recaptured.
6. A total of eight fish representing surrogate species (flannehnouth sucker and northern pike)
were documented moving over the diversion structure during the study; four passing in an
upstream direction and four passing in a downstream direction.
7. Fish passage was documented during high flows (> 224 cfs) and low flows (< 224 cfs).
8. Three radiotagged northern pike passed upstream over the diversion structure at flows ranging
from 268 to 1680 cfs.
9. No evidence of fish aggregations was found below the diversion structure during the study,
indicating that the structure did not impede upstream movement.
10. Physical habitat parameters including depth and velocity measured in the diversion structure
during low flows were within the range of utilization documented for Colorado squawfish.
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