9433

• UCREFRP Catalog Number: 9433
• Author: Anderson, R.
• Title: Riverine Fish Flow Investigations.
• USFW Year: 2002.
• USFW - Doc Type: Federal Aid Project F-288-R5,
• Copyright Material: NO

Table 6. Species composition for fish over 15 em and less than 15 em for Corn Lake and
Clifton in the IS-MILE Reach, Colorado River, September/October 2001

Corn Lake Clifton Corn Lake Clifton
Species 2001 >15 em 2001 >15 em 2001 < 15 em 2001 <15 em
Flannelmouth Sucker 39.5% 42.0% 2.4% 3.4%
Bluehead Sucker 38.1% 26.8% 1.9% 1.8%
Roundtail Chub 2.9% 5.9% 5.5% 12.3%
Colo. Pikeminnow 0.03% 0.09% 0.0%
Razorback Sucker 0.06% 0.04%
White sucker 5.1% 3.3% 8.8% 2.6%
White X Flannelmouth 0.5% 0.7% 0.0%
White X Bluehead 0.6% 0.09% 0.1% 0.0%
Channel Catfish 4.7% 5.7% 0.1%
Carp 6.1% 13.8% 13.1% 6.9%
Smallmouth Bass 0.1% 0.4%
Largemouth bass 0.4% 0.8% 5.4% 6.1%
Green Sunfish 0.3% 0.3% 26.6% 16.9%
Brown trout 1.4% 0.2% 0.0% 0.0%
Rainbow trout 0.04% 0.2% 0.0%
Black Bullhead 0.40% 1.6% 0.3%
W. Crappie 0.1% 0.0%
Speckled Dace 33.4% 47.2%
Mottled Sculpin 0.8% 1.8%
Red Shiner Xx 0.0%
Sand Shiner Xx
Fathead Minnow Xx
Bluegill 0.3%
NATIVE 80.7% 74.8% 44.0% 66.4 %
Sample size 3463 4485 1630 1481

Roundtail chub composition was higher at Clifton than Corn Lake in the three years. In
2001 roundtail chub were 3% at Corn Lake and 6% at Clifton. In 1999, 2000 and 2001 roundtail
chub percentages at Corn Lake were 3%, 4% and 3%, respectively and were 7%, 5%, and 6%,
respectively at Clifton (Table A4). Colorado pikeminnow are very rare in the samples with only
one collected at Corn Lake and four at Clifton in 2001. All razorback sucker were hatchery fish
and only two at each station were captured in 2001. Native fish comprised 76%, 72% and 81%
of the catch at the Corn Lake station in 1999,2000 and 2001, respectively. At Clifton native fish
composition was 63%, 78% and 75% from 1999, 2000 and 2001, respectively.

The stability in species composition for flannel mouth, bluehead and roundtail chub has
been generally maintained over the three years. This indicates stability in environmental factors
and that habitat availability was consistent for these fish during the study period. The sample in
2000 differed somewhat from the other years in that flannel mouth were less common (31 %) in
Corn Lake and bluehead were more common (41%) at Clifton compared to other years. Also

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