6006

• UCREFRP Catalog Number: 6006
• Author: Holden, P. B. and L. W. Crist.
• Title: Documentation of Changes in the Macroinvertebrate and Fish Populations in the Green River Due to Inlet Modification of Flaming Gorge Dam
• USFW Year: 1981.
• USFW - Doc Type: Final Report.
• Copyright Material: NO

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FIELD RESULTS

General
The field results of this study are presented in this report to
show changes since inlet modification in June 1978. Therefore
"before" data include the March, June, and July samples of 1978. July
was included for it was assumed that fishes would not react that
quickly to the warmer flows and the data tend to support that assump-
tion. The major comparisons made are between years to show what
changes occurred. Differences in samples between the various months
of a year, except for 1980, are notdiscussed in detai 1 here~ but were discussed
in the annual reports for 1978 and 1979 (Holden and Crist 1979, 1980).
Therefore, this report focuses on the major results of the study.
Physical Factors
Table 5 summarizes the temperatures and flows of the Green River
at Greenda 1 e and Jens.en for the three years of the study. Releases
from the dam were considerably lower in 1978 than the mean for
1967-1977 (Table 1). Flows in 1979 were higher than the 1967-1977
norm in February through April, but lower in May through October.
Flows in 1980 were also high in January and February, but were fairly
low March through July, especially in June and July when compared to
the other two years. Flows in August and September 1980 were slightly
higher than 1979 levels.
Temperatures at Greendale increased markedly in June of 1978, when
the inlet modifications became operational. Since that time,