9547

• UCREFRP Catalog Number: 9547
• Author: Tyus, H. M. and J. F. S. III.
• Title: An Evaluation of Recovery Needs for Endangered Fishes in the Upper Colorado River, with Recommendations for Future Recovery Actions - Final Report.
• USFW Year: 1999.
• USFW - Doc Type: Glenwood Springs, CO.
• Copyright Material: NO

• The relationship between flows and the amount of nursery habitat for Colorado
pikeminnow in the UCR should be more fully evaluated, because this information
could provide important guidance for developing flow management strategies.
• Flows required by the young of the other endangered fishes- are virtually unknown.
More effort should be expended to obtain habitat needs for these fishes as well, and
to determine the role of instream flows during this critical life stage.
~ Habitat Development and Restoration:
• Physical habitat modifications should be explored as an alternative to flow
manipulations, such as improving adult habitat for Colorado pikeminnow in the 15-
Mile Reach, or in other locations where water supplies are limited or other
constraints warrant such an approach.

• The abundance of "preferred" prey may be more important than physical habitat
quality for determining the abundance of adult Colorado pikeminnow in the 15-Mile
Reach, yet past studies seem to ignore this possibility. The relationship between
food and physical habitat needs to be more fully explored.
• Adult Colorado pikeminnow make use of upstream areas that support abundant
populations of native prey species. Access should be provided to areas upstream of
the 15-mile reach in the UCR, because if the fish gain access to upper reaches
(containing preferred prey), individuals may grow faster and the population may
~ increase in numbers.
• The locations of actual and potential spawning habitat is not known adequately and
should be determined for Colorado pikeminnow in the UCR.
~ • If nursery habitat is found to be limiting for Colorado pikeminnow in the UCR,
physical habitat modifications may offer a means of augmenting nursery habitat.
Stocking of Endangered Fishes:
• Previous reintroductions have not been very successful in terms of increasing
r demonstrably the sizes of populations of endangered fishes. Future reintroductions
should reflect a better appreciation of life history needs.
• Stocked fish may behave differently than wild fish, and this has important
ram cations for implementing recovery actions. Future reintroduction protocols
need to be designed to anticipate this possibility.
• Habitat in, and above, Debeque Canyon offers potentially important habitat for
translocating juvenile or adult Colorado pikeminnow and humpback chub, and
should be evaluated for this purpose.
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