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

Comparison offish community composition across the longitudinal gradient in Lodore
and Whirlpool canyons between 1994 to 1996 and 2002 to 2004 periods, electrofishing
samples.-Electrofishing of mostly large-bodied fishes in Lodore and Whirlpool canyons in
2002 to 2004 captured relatively fewer species upstream than downstream, taxa in upstream
reaches were cold-water or cool-water tolerant, and downstream were tolerant of cool or warm
water (Tables 4 and 5). A total of 25 fishes were detected by electrofishing; species richness in
electrofishing samples in the LD 1 to LD4 reaches in Lodore Canyon and the WH 1 and WH2
reaches in Whirlpool Canyon was 15, 13, 17, 19, 21, and 20, respectively. Relatively low
species richness in reach LD2 was due to absence of roundtail chub and rare non-native fishes
that were present downstream.
In the upstream LD1 reach in 1994 to 1996, seven native and eight introduced species
and four hybrids were detected by electrofishing. In decreasing order of abundance,
flannelmouth sucker, brown trout, common carp, bluehead sucker, and redside shiner were the
five most common species collected, and represented 72% of the total assemblage. Native
species were 51 % of the total. In LD 1 in the 2002 to 2004 period, seven native and nine
introduced species and four hybrid combinations were detected by electrofishing. Brown trout,
flannelmouth sucker, white sucker, common carp, and channel catfish were the five most
common species, and made up 72% of the fish community. Native fishes were 32% of the total.
Increased abundance of channel catfish in the 2002 to 2004 was notable.
In reach LD2 in 1994 to 1996, seven native and seven introduced species and four
hybrids were captured by electrofishing. Flannelmouth sucker, brown trout, bluehead sucker,
mountain whitefish, and common carp were the most common species collected, and represented
87% of all fish captured. Native species represented 62% of the fish community by number. In
LD2 in the 2002 to 2004 period, six native and seven introduced species and three hybrids were
captured by electrofishing. Brown trout, flannelmouth sucker, bluehead sucker, white sucker,
and common carp were the five most common species, and made up 86% of the fish community.
Native fishes were 42% of the total.
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