7747

• UCREFRP Catalog Number: 7747
• Author: Burdick, B. D. and L. R. Kaeding.
• Title: Biological Merits of Fish Passage as Part of Recovery of Colorado Squawfish in the Upper Colorado River Basin.
• USFW Year: 1990.
• USFW - Doc Type: Grand Junction, CO.
• Copyright Material: NO

also be exposed to appreciable angling mortality. Such problems might occur in
Kenney Reservoir on the White River, for example, if a passageway were installed on
Taylor Draw Dam.
Temperatures of tailwater releases below high-head dams are usually much
colder during the warm-weather months than are those that would have occurred
there prior to the dam. Colorado squawfish moving upstream may avoid these
Coldwater discharges. Tailwaters may need to be warmed perhaps through the
installation of multilevel outlet works, to attract fish to the passageway. At dams that
modify the temperature regime of the downstream river, fish-passage considerations
need to include assessments of how the temperature of the river downstream might
be made more favorable to the fishes.
Information needs
Several important information needs must be met in the process of determining
the usefulness of fish passageways to the recovery of Colorado squawfish. First,
clear, objective recovery goals for Colorado squawfish need to be established. These
are of fundamental importance because they are the criteria against which the
potential benefits (and costs) of a proposed passageway must be weighed.
The second important need is for identification of the factors having important
limiting effects on the Colorado squawfish population. This is important because use
of a passageway by fish could help to ameliorate the effects of some limiting factors,
but not of others. For example, as discussed earlier, if the availability of spawning
habitat or habitat for adult fish is limiting the population, then the provision of fish
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