7378

• UCREFRP Catalog Number: 7378
• Author: Wydoski, R. S.
• Title: Potential Impacts of Alterations in Streamflow and Water Quality on Fish and Macroinvertebrates in the Upper Colorado River Basin.
• USFW Year: 1980.
• USFW - Doc Type: 77-147
• Copyright Material: YES

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suitability for inclusion in a national or state system of wild. scenic. or

reservoirs and techniques for reducing or "controlling" the populations of

recreational rivers before this option is lost to the American public forever

undesirable fish species.

(Neuhold. Herrick. and Patten. 1975; U.S. Water Resources Countil. 1971).

Numerous other recommendations for research based on various goals

5. Establishing methodologies for determining streamflow require-

and objectives have been made by the persons and in the reports listed

at the beginning of this section. I believe that the research priorities

outlined above for fish and macroinvertebrates are the most critical ones

ments for fish and macroinvertebrates. This research should include the

impacts of different flows on the entire watershed. including the impacts

on water quality. wildlife. and noncODsumptive recreation.

for the Upper Colorado River Basin as they relate to potential energy de-

A number of comprehensive studies have recommended that the impact

velopment there.

of streamflow on fish be included as a priority for research (Lord. Tubber-

SUIIIII&ry

ing. and Althen. 1975; Neuhold. Herrick. and Patten. 1975; Stalnaker and

6. Determining management strategies for manipulating fish popu-

I have attempted to summarize the potential impacts of alterations

in streamflow and water quality on fish and macroinvertebrates in the

Upper Colorado River. and to offer recommendations for research. The

importance of the Colorado River was outlined. and the fish fauna was

described with examples of changes that have already resulted in this

fauna from the construction of impoundments as well as of problems that

may result from the supply and demand for sport fishery in this region.

Various examples were used to indicate the relationship between stream-

flow and water quality and the ecology of fish and macroinvertebrates.

with examples used from the Upper Colorado River where possible. Recom-
mendations for priority research were based on a number of comprehensive

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Arnette. 1976). Stalnaker and Arnette recommended a refinement in method-

01081 for streamflow assessment to make it applicable to large rivers,

They also recommended that intensive research be conducted to determine

the ecological impacts of extreme fluctuations and repetitive short-term

fluctuations in streamflows. perhaps using target species of fish or inver-

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tebrates, Further. they emphasized the need for long-term research to

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develop and validate the relationship between streamflow and populations

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or production of aquatic organisms for reliable. predictive purposes.

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lations (both game and undesirable species) in reservoirs, This problem

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is considered high on the list of research priorities for the Rocky Moun-

tain states where impoundments and water resources are closely linked.

studies of the region.

titative knowledge of the interrelationships among fish populations. their

Management of the Upper Colorado River Basin must be done on the

basis of the goals and objectives to serve society in the entire basin.

Development or alterations to this river system upstream can have an

effect on fish. macroinvertebrates and people far downstream. Simons

Most of the past management failures can be attributed to a lack of quan-

food chain relationships. and limnology, Selection of sampling gear and

the behavior of the fish species are some basic problems in providing
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quantitative information, Other problems include productivity of the