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<br />Flows at Mineral Bottom are difficult to control given the distance of the site from Flaming Gorge
<br />Dam. Additionally, the San Rafael River occurs between the USGS gauge at Green River, Utah,
<br />and Mineral Bottom. Because Mineral Bottom and other lower Green River sites are important
<br />nursery areas for Colorado squawfish, future studies should be conducted to determine the effect
<br />of recommended flows at the USGS Jensen gauge on sites in the lower river.
<br />
<br />Our data indicate that flows above 55 to 71 m3 Is have a detrimental effect on backwater habitat
<br />availability. Tyus et al. (1987) found marked decreases in nursery (backwater) habitat with high
<br />flows and reported a decrease in the Colorado squawfIsh yoy catch rate as flows in the Green River
<br />were increased. If this situation occurs during the primary nursery season, the growth and survival
<br />of yoy Colorado squawfish could be adversely effected.
<br />
<br />Remote sensing is an effective technique for obtaining data on backwater availability relative to
<br />varying riverflows. Remote sensing techniques cannot replace IFIM techniques for modeling river
<br />systems. However, for backwater habitat delineation and monitoring, remote sensing is a more
<br />efficient and accurate method on which to base management decisions. Modeling several
<br />backwaters with IFIM to characterize hundreds of backwaters on a large system would be difficult
<br />as backwaters vary tremendously in their size, depth, and permanence.
<br />
<br />BIBLIOGRAPHY
<br />
<br />Andrews, E. D., "DOWnstream effects of Flaming Gorge Reservoir on the Green River, Colorado
<br />and Utah," Geological Society of America Bulletin 97:1012-1023, 1986.
<br />
<br />Bailey, N.T.J., "Statistical methods in biology," Hodder and Stoughton, London, England, 1981.
<br />
<br />Gore, J. A., and J. M. Nestler, "Instream flow studies in perspective, Regulated Rivers: Research
<br />and Management," 2:93-101, 1988.
<br />
<br />Graf, W. L., "The effect of dam closure on downstream rapids," Water Resources Research
<br />16:129-136, 1980.
<br />
<br />Holden, P. B., "Habitat requirements of juvenile Colorado squawfish," U.S. Fish and Wildlife
<br />Service, Office of Biological Services, Fort Collins, Colorado, FWSIOBS-77/65, 71P, 1977.
<br />
<br />Holden, P. B., and C. B. Stalnaker, "Distribution and abundance of mainstream fishes of the middle
<br />and upper Colorado River basins, 1967-1973," Transactions American Fisheries Society, 104,
<br />217-231, 1975. .
<br />
<br />Pucherelli, M. J., R. C. Clark, J. N. Halls, S. Wilds, and R. Williams, "A pilot study to evaluate
<br />backwater habitat on the Green River using aerial photography and GIS," Proceedings, U.S. Army
<br />Corps of Engineers Sixth Remote Sensing Symposium, 1987.
<br />
<br />Rose, K. L., and D. R. Hann, "Consolidated Instream Flow Report Habitat Modeling on the Green
<br />River in Utah," U.S. Fish and Wildlife Service, Upper Colorado River Basin Instream Flow Team,
<br />Grand Junction, Colorado, 1989.
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