9548

• UCREFRP Catalog Number: 9548
• Author: Finney, S.
• Title: Adult and Juvenile Humpback Chub Monitoring for the Yampa River Population, 2003-2004.
• USFW Year: 2006.
• USFW - Doc Type: 133,
• Copyright Material: NO

Conclusion and Recommendations
Due to low numbers of adult captures and poor juvenile identification, meeting
study objectives proved difficult. In light of historic and current study data distribution of
the population has been defined in Dinosaur National Monument, but humpback chub
may be present in other nearby areas. Length frequency, while quantified, is weak
considering the low number of juveniles. Similarly, a low number of captures made adult
abundance estimates impossible. The ability to differentiate juvenile G. cypha from G.
robusta in this population limited the ability to draw inference from these data.
The Yampa population of humpback chub has declined and is nearly extirpated.
The low number of individuals makes a population estimate impossible. However, some
level of monitoring should be continued to determine if the population has increased
enough to support a population estimate. If humpback chub in Yampa Canyon prove to
be genetically unique, their genetic diversity should be preserved by moving fish to a
refuge. Recommendations are as follows:
1) Eliminate Lodore Canyon and Split Mountain Canyon from further attempts to
study the Yampa population. If incidental capture of humpback chub occur in the
future in these areas, effort should be expanded.
2) Annually monitor Gila spp.nursery areas in Yampa Canyon, Whirlpool Canyon,
and Island Park.
3) Sample Cross Mountain Canyon and the Little Snake River for the presence of
humpback chub.
4) Fish should be immediately removed from the canyon to refugia to preserve
genetic material.
5) The population estimation element of recovery for this population should be
suspended until more individuals are available for sampling.
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