9549

• UCREFRP Catalog Number: 9549
• Author: Bestgen, K. R., K. A. Zelasko, R. I. Compton and T. Chart.
• Title: Response of the Green River Fish Community to Changes in Flow Temperature Regimes from Flaming Gorge Dam since 1996 based on sampling conducted from 2002 to 2004.
• USFW Year: 2006.
• USFW - Doc Type: 115,
• Copyright Material: NO

documentation of fish community changes, such as new or ongoing species invasions that may
otherwise be attributed to flow or temperature changes. Once additional years of sampling data
are accumulated under different flow and temperature regimes, managers can make informed
decisions about the effects of Flaming Gorge recommendations on the native fish community,
including endangered fishes.
Recommendations for temperature and fish community monitoring in the Green River
downstream of flaming Gorge Dam.
Temperature monitoring.-We recommend continued collection of water temperature data
and the addition of real-time temperature monitoring stations at Echo Park in the lower Yampa
River and in the Green River just upstream of the Yampa River. An alternative to real-time
monitoring is to model flow-specific temperature differences in each river. This will allow for
continuous monitoring of the summer water temperature differences between the two systems
when Colorado pikeminnow are drifting into the Green River from the Yampa River.
Large-bodied fish sampling recommendations.-We recommend two electrofishing
sampling passes, one in summer and one in autumn. Samples collected during those times had
the highest species richness and fish density. A main advantage of summer sampling may be to
demonstrate use of Lodore Canyon by spawning Colorado pikeminnow, when water temperatures
are warm. Monitoring of potential spawning by Colorado pikeminnow in Lodore Canyon may
also be accomplished by drift net sampling in lower Lodore Canyon. Autumn electrofishing
sampling is useful because capture rates were high. Using both summer and autumn sampling
increases the likelihood that at least one sampling pass will have conditions conducive to high
sampling efficiency.
Whirlpool Canyon chub sampling recommendations.-Confirmation of a small population
of humpback chub in Whirlpool Canyon and capture of stocked bonytail and substantial numbers
of roundtail chub suggest that additional monitoring should occur to document status of those
populations and response to operational changes at Flaming Gorge Dam. One sampling pass of
three to four days with trammel nets under low flow conditions in late summer or autumn
sampling is recommended because water temperatures are relatively low and may reduce
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