8165

• UCREFRP Catalog Number: 8165
• Author: Czapla, T. E.
• Title: Genetics Management Plan ‎(Revised)‎.
• USFW Year: 1999.
• USFW - Doc Type: Denver, Colorado.
• Copyright Material: NO

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Table 1. Criteria used for identifiption and characterization of presumptive endangered fish stocks in the Upper
Colorado River Basin (Y=Yes, determined; U=Unknown, little or no information; ?=Undetermined, inoondusive or unagreed
upon results based on information available). See Appendix 2 for background information.
Criteria'
Speces Presumptive Spawning Fidelity to Geographic Molecular Morphometric
Stocks Sites/ Spawning Genetics
Movements Sites
Razorback sucker Middle Green River Y Y Y ? U
(Yampa and Middle
Green River)
Lower Green River U U Y ? U
Upper Colorado River Y U Y ? U
Bonytail Upper Basin
Humpback chub Yampa River Y U Y ? Y
Desolation-Gray Y U Y ? U
Canyons
Blade Rocks Canyon Y U ? ? U
Westwater Canyon Y U ? ? U
Cataract Canyon Y U Y ? U
Colorado Green/Yampa River Y Y Y ? U
pikeminnow
Desolation-Gray Y Y Y ? U
Canyons
Upper Colorado River Y U Y ? U
including Gunnison
River
Definitions of Criteria:
Spawning sites/movements - Ripe fish collected on suspected spawning sites; larval fishes collected
downstream of suspected spawning sites. Migrations to/from spawning sites;
home ranges.
Fidelity to spawning sites - Fish return exclusively to the spawning sites they originated at.
Geographic - Stocks that are spatially separated from others by large distances (e.g., 100 river mites).
Molecular Genetic - Allozyme or mtDNA analyses indicating separation of stocks.
Morphometric -Systematic body measurements indigting differences among stodks/spedes.
V. STATUS AND TRENDS OF ENDANGERED FISH STOCKS AND CURRENT GENETIC
MANAGEMENT ACTIONS
Criteria for Determining Status and Trends of Endangered Fish Stocks. De+ ~n~ g the status and trends of
endangered fish stocks is imperative in making informed management decisions (Philipp et al. 1986).
Decisions on actions regazding endangered species must be made on a case-by-case basis using standard
criteria (Rohlf 1991) as developed here. The status of presumptive endangered fish stocks in the upper basin
is determined by:
1. Monitoring the distribution and relative abundance of presumptive stocks by species,
2. Documenting spawning and recruitment,
3. Determining the potential risk for extinction from catastrophes, and
4. Estimating the probability for immediate extinction.
Distribution and relative abundance of Colorado pikeminnow in the upper basin and humpback
chubs in Black Rocks and Westwater Canyons are estimated through the Recovery Program's Interagency
Standardized Monitoring Program (McAda et al. 1993). Data on the present relative abundance as well as
status and trends of the razorback sucker and nonnative fishes aze obtained through the basinwide razorback
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