7039

• UCREFRP Catalog Number: 7039
• Author: Pearson, W. D., R. H. Kramer and D. Franklin
• Title: Macroinvertebrates in the Green River Below Flaming Gorge Dam, 1964-65 and 1967
• USFW Year: 1968
• USFW - Doc Type: Utah Academy of Sciences, Arts & Letters
• Copyright Material: YES

MACROINVERTEBRATES IN THE GREEN RIFER
BELOW FLAMING GORGE DAM, 1964-651 AND 1967
WILLIAM D. PEARSON, ROBERT H. KRAMER,
AND THE LATE DONALD R. FRANKLIN
Utah State University
INTRODUCTION
f Two months before Flaming Gorge Dam on the Green River
was closed in 1962, 700-800 km of the river and its tributaries
were treated with rotenone to suppress rough-fish populations
(Binns et al., 1964). Effects of the rotenone treatment and of the
dam's subsequent operation upon downstream invertebrates were
largely speculative. This paper reports postimpoundment obser-
vadons made during two studies conducted on the Green River
below Flaming Gorge Dam. The first was done by Pearson and
Franklin in 1964 and 1965. Their major objectives were to describe
the changes in river environment after closure of the dam and to
determine the postilmpoundment distribution of macroinvertebrates
and compare it with that reported before the dam was built. The
second set of observations was made by Pearson and Kramer in
1967 during. in attempt to investigate Baetis population-dynamics
immediately below Flaming Gorge Dam. Though unsuccessful
in its major objective, this study provided information on unex-
pected effects of Flaming Gorge Dam upon downstream inverte-
brates. Both studies document some changes which have occurred
below Flaming Gorge Dam, and the findings should be useful
for future comparative purposes.
METHODS AND MATERIALS
Collections were made from June 1, 1964, to September 1,
1965, and from June 1S to October 14 in 1967. During 1964 and
1965, samples were taken every 2-4 weeks in the summer at four
stations (Figure 1): Little Hole (11.7 km below Flaming Gorge
Dam = 11.7 KBD), Carr Ranch (63.7 KBD), Echo Park - above
the mouth of the Yampa River (103.9 KBD), and Island Park
(125.5 KBD). One or two summer collections were also made at
nine supplementary stations. Weekend collecting trips were made
'Portion of a Master's thesis by the senior author.
148
Reprinted from Proceedings of Utah Academy of Sciences, Art; & Loters -- Volume 45, Part I.

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