7150

• UCREFRP Catalog Number: 7150
• Author: Holden, P. B. and L. W. Crist.
• Title: Documentation of Modification of Endemic Fish Species and Macroinvertebrates in the Green River below Flaming Gorge Dam.
• USFW Year: 1978.
• USFW - Doc Type: Logan, Utah.
• Copyright Material: NO

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subst~ate, 100 meters below Wade and Curtis Campground. Samples from
March have been analyzed, but analysis of June samples has not been
completed.
Fishes have been sampled with a raft-mounted electrofishing unit
and seines. Six stations on the Green River (Lodore, Alcove Brook,

Echo Park, Island Park, Split Mountain, and Jensen) and two on the
Yampa (Lily Park and Lower Yampa) are being sampled as outlined in the
proposal. The only change is that the Jensen station was moved from
the Jensen U.S.G.S. gaging station location to below the Highway 40
bridge near the town of Jensen, Utah. This change was made in the June

sample after it was noted in March that the Jensen and Split Mountain

stations were too close together.

RESULTS

Macroinvertebrates

Table 1 summarizes taxa and mean abundances for the March

macroinvertebrate samples. Baetids, simulids and chironomids were
found at all four stations. Crustaceans were found primarily at Little
Hole and Taylor Flats, near Flaming Gorge Dam. The greatest number of
organisms was found at these two stations also.

Table 2 gives mean species diversity for each station, according
to the Shannon-Weaver Species Diversity Index. The upper (Lodore) and

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lower (Jensen) stations had similar diversities, and were considerably

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more diverse than the middle two stations.