9301

• UCREFRP Catalog Number: 9301
• Author: Wydoski, R. S.
• Title: Green River Fishes and Invertebrates.
• USFW Year: 1967.
• USFW - Doc Type: Logan, UT.
• Copyright Material: NO

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RECOMMENDATIONS
Studies to determine spawning areas and ecological requirements necessary
to assure successful reproduction of indigenous fishes should be continued.
The absence of young-of-the-year humpback suckers may indicate reproductive
failure. Concurrent studies of movement patterns of native fishes should
- also -be -made-.to -evaluate -ecological significance of dispersal and migrations
within the Green and Yampa River systems.
No water developments should be made on the Yampa River upstream from
Dinosaur National Monument until further studies are made to locate other
areas inhabited by the indigenous Green River fishes. Evidence to the present
Y time1indicates-these unique fishescontinue to survive in Dinosaur National
Monument only because of the modifying effects of the Yampa River upon water
quality of the Green River, principally temperature. If water temperatures
in the Yampa River were lowered to that of the Green, the probability is great
that the Colorado chub, Colorado squawfish, bluehead sucker, and humpback
sucker would disappear from the waters of Dinosaur.
Studies to clarify the taxonomy of the Gila robusta complex and of Gila
cypha should be continued throughout the entire Colorado River basin. Con-
current studies of the ecological requirements and genetic variability among
the various biological entities of Gila are needed to provide information
essential to the design of programs to save the rarer forms ftom extinction.
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