9526

• UCREFRP Catalog Number: 9526
• Author: LaGory, K. E., J. W. Hayse and D. Tomasko.
• Title: Recommended Priorities for Geomorphology Research in Endangered Fish Habitats of the Upper Colorado River Basin.
• USFW Year: 2003.
• USFW - Doc Type: Argonne, Illinois.
• Copyright Material: NO

Geomorphology Research Priorities
EXECUTIVE SUMMARY
September 2003
Activities of the Upper Colorado River Endangered Fish Recovery Program (Recovery
Program) include habitat improvement and management (e.g., restoration of flooded bottomlands,
provision of fish passage) and flow management to provide suitable habitat conditions for the
four species of endangered fishes in the Upper Colorado River Basin - Colorado pikeminnow
(Ptychocheilus lucius), humpback chub (Gila cypha), bonytail (Gila elegans), and razorback
sucker (Xyrauchen texanus). In this report, we identify and apply an approach for prioritizing
river reaches and habitats for geomorphic research in the Upper Colorado River Basin.
The goal of this project was to identify priorities for geomorphology research in
endangered fish habitats of the Upper Colorado River Basin. These recommended priorities
provide input to the Recovery Program as it develops a comprehensive research and monitoring
program for endangered fish habitats. Project objectives included:
• Review and consolidate geomorphic, habitat, and flow information;
• Identify relationships among flow regimes, habitats, fish needs, and recovery goals;
and
• Identify data gaps and rank their importance to recovery.
The report focuses on the reaches and habitats used by life stages (larvae, juveniles,
subadults, adults, and spawning) of three of the four species - the Colorado pikeminnow,
humpback chub, and razorback sucker. Insufficient information was available on the bonytail to
permit a meaningful evaluation. The evaluation includes the Green River between Flaming
Gorge Dam and its confluence with the Colorado River and the upper Colorado River upstream
of the headwaters of Lake Powell. Major tributaries of these two rivers, up to the point of
occupation by endangered fishes, also were included.
We developed a linked-matrix approach to systematically and objectively identify overall
priorities for research. Spreadsheets were developed that contained scores (0, 1, 2, or 3) to
represent relative importance of (1) existing reach use for species and life stages, (2) habitat use
for species and life stages, (3) habitat occurrence within planform types, and (4) dependencies
between habitat characteristics and hydrologic and geomorphic parameters. Scores also were
assigned to life stages and species on the basis of sensitivity to environmental variability and
population status, respectively. These scores enabled weighting of life stages and species when
scores were combined to determine overall priorities. Weights were applied in a phased manner
that enabled consideration of priorities at various levels, including (1) species-life stage,
(2) species, and (3) all species combined. Scores were developed during two workshops attended
by researchers from various agencies, consulting firms, and universities.
The Upper Colorado River Basin was subdivided into the Green River subbasin and the
upper Colorado River subbasin. Each major river was divided into reaches based on the
dominant geomorphic planform (restricted meander, fixed meander, and canyon). These
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