7363

• UCREFRP Catalog Number: 7363
• Author: Haines, G. B. and H. M. Tyus.
• Title: Influence of Environmental Factors on Distribution and Abundance of Age-0 Colorado Squawfish in the Green River, Utah.
• USFW Year: 1989.
• USFW - Doc Type: Vernal, Utah.
• Copyright Material: NO

However, the high degree of environmental variability in the Green River
and sampling bias inherent in studying such a system no doubt affected
our ability to perceive similarities or differences in habitat
requirements, and this study did not evaluate microhabitat use. We were
further constrained in evaluating potential effects of the current
dominance of introduced fishes as a factor in the decline of the endemic
Colorado River fishes, because historic information on native fishes in
backwaters is virtually non-existent. We recommend more controlled
studies on habitat use and requirements of native fishes and their
potential interactions with introduced forms.

ACKNOWLEDGEMENTS
We thank numerous colleagues at the Vernal Field Office, Colorado
River Fishes Project, who collected field data 1979-1988 and assisted
with data entry and analysis. C. Karp provided helpful review comments
on an earlier draft of the manuscript. D. Moses prepared graphics and
provided technical support. The study was funded by the Bureau of
Reclamation and Fish and Wildlife Service, U.S. Department of Interior.

LITERATURE CITED
Behnke, R.J. and D.E. Benson. 1983. Endangered and threatened fishes of
the upper Colorado River basin. Cooperative Extension Service,
Colorado State University, Fort Collins. Bulletin 503A. 38 pp.
Black, T., and R.V. Bulkley. 1985a. Preferred temperatures of yearling
Colorado squawfish. Southwestern Naturalist 30(1):95-100.

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