9363

• UCREFRP Catalog Number: 9363
• Author: Muth, R. T., L. W. Crist, K. E. LaGory, J. W. Hayse, K. R. Bestgen, J. K. Lyons, T. P. Ryan and R. A. Valdez.
• Title: Flow Recommendations for Endangered Fishes in the Green River Downstream of Flaming Gorge Dam.
• USFW Year: 1999.
• USFW - Doc Type: Lakewood.
• Copyright Material: NO

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Draft - Do Not Cite

May 1999

Page

4.3 RAZORBACK SUCKER. . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-61
4.3.1 Distribution and Status Overview ............................. 4-61
4.3.2 Life History Overview . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . 4-62
4.3.3 Research on Razorback Sucker for the 1992 Flaming
Gorge Biological Opinion ......................',.......... 4-64
4.3.4 Research on Razorback Sucker for the 1990-1996 Flaming
Gorge Flow Recommendations Investigation ..........,........ 4-64
4.3.5 Ecology of Razorback Sucker in the Green River System .......... 4-65
4.3.5.1 Distribution and Abundance ..........................4-65
4.3.5.2 Life History by Season. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-67
4.3.6 Summary of Seasonal Flow-Habitat Relationships for
Razorback Sucker in the Green River System . . . . . . . . . . . . . . . . . . . 4-85

4.3.6.1 Spring ..........................,................ 4-85

4.3.6.2 Summer and Autumn ............................... 4-87

4.3.6.3 Winter........................................... 4-89

4.4 HUMPBACK CHUB .............................................. 4-93
4.4.1 Distribution and Status Overview ............................. 4-93
4.4.2 Life History Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-95
4.4.3 Research on Humpback Chub for the 1992 Flaming Gorge
Biological Opinion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-97
4.4.4 Research on Humpback Chub for the 1990-1996 Flaming
Gorge Flow Recommendations Investigation ................... 4-97
4.4.5 Other Recent Research on Humpback Chub ..................... 4-98
4.4.6 Ecology of Humpback Chub in the Green River System ........... 4-98
4.4.6.1 Distribution and Abundance . . . . . . . . . . . . . . . . . . . . . . . . . . 4-98
4.4.6.2 Life History by Season .............".. . . . . . . . . . . . . 4-102
4.4.7 Summary of Flow-Habitat Relationships for Humpback
Chub in the Green River System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-114
4.4.7.1 Spring ..........................,............... 4-114
4.4.7.2 Summer and Autumn .............................. 4-115
4.4.7.3 Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-115

5 FLOW RECOMMENDATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.1 SUMMARY OF SPECIES NEEDS AND FLOW RELATIONSHIPS. . . . . . . .. 5-1
5.2 RECOMMENDED FLOWS AND IMPLEMENTATION APPROACH ....... 5-5
5.2.1 Reach 1 - Flaming Gorge Dam to the Yampa River

Confluence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

5.2.2 Reach 2 - Yampa River to the White River Confluence. . . . . . . . . . . . 5-20
5.2.3 Reach 3 - White River to the Colorado River Confluence .......... 5-21
5.3 ENHANCEMENT OF SUMMER WATER TEMPERATURES ............ 5-22

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