9299

• UCREFRP Catalog Number: 9299
• Author: Anderson, R. and J. Mumma.
• Title: Aspinall Studies
• USFW Year: 1999.
• USFW - Doc Type: Annual assessment of Colorado Pikeminnow Larval Production in the Gunnison and Colorado Rivers, Colorado 1992-1996.
• Copyright Material: NO

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Table 1. Species composition of fish collected at all study sites in
the Colorado River, 1992 to 1996.

YEAR STATION NATIVE CPM BH CH FM SD
1992 LOMA 71.5% 2.1% 13.6% 27.8% 4.2% 23.7%
1992 UPPER 87.4% 0.0% 31.1% 15.5% 14.6% 26.2%
1993 LOMA 90.0% 1.9% 8.8% 50.6% 1.7% 27.0%
1993 UPPER 94.6% 0.0% 17.7% 29.2% 24.6% 23.1%
1994 LOMA 42.0% 1.5% 3.9% 12.1% 1.3% 23.2%
1994 MIDDLE 61.2% 2.3% 7.6% 22.3% 3.2% 27.0%
1994 UPPER 95.6% 0.0% 7.1% 25.8% 3.6% 59.1%
1995 LOMA 92.0% 3.6% 9.6% 23.5% 0.2% 55.1%
1995 MIDDLE 94.9% 0.9% 16.6% 13.6% 0.2% 63.6%
1995 UPPER 99.1% 0.2% 8.8% 8.2% 0.2% 81.8%
1996 LOMA 89.7% 1.9% 2.9% 47.7% 1.7% 35.5%
1996 MIDDLE 86.0% 2.8% 7.3% 29.3% 8.9% 37.7%
1996 UPPER 95.1% 0.0% 3.5% 24.5% 6.3% 60.8%
YEAR STATION NONAT CP FH GS SHlNER WS
1992 LOMA 26.8% 9.8% 14.1% 0.2% 1.9% 0.0%
1992 UPPER 11. 7% 1.9% 1.0% 0.0% 8.7% 0.0%
1993 LOMA 10.0% 9.4% 0.2% 0.0% 0.2% 0.2%
1993 UPPER 4.6% 1.5% 0.0% 0.0% 0.0% 3.1%
1994 LOMA 55.4% 1.8% 48.6% 0.2% 4.7% 0.0%
1994 MIDDLE 35.8% 1.4% 32.0% 1.1% 2.4% 0.0%
1994 UPPER 4.0% 2.0% 1.2% 0.0% 0.0% 0.4%
1995 LOMA 6.2% 1.6% 3.3% 0.8% 0.6% 0.0%
1995 MIDDLE 4.0% 0.1% 1.0% 2.3% 0.6% 0.0%
1995 UPPER 0.7% 0.1% 0.2% 0.3% 0.1% 0.0%
1996 LOMA 10.3% 2.0% 2.8% 0.4% 4.6% 0.5%
1996 MIDDLE 13.1% 2.5% 0.3% 1.1% 3.4% 5.9%
1996 UPPER 3.5% 0.0% 0.7% 0.7% 0.7% 1.4%

Chub was the most common fish collected on the Gunnison stations in aU years
except in 1994 when it was carp and shiners (Table 2). Numbers of chub collected in
1994 were very low at the two lower Gunnison stations (34 and 137, respectively)
compared to their highest year, 1,087 in 1995 on the Below Redlands and 1,095 in 1993
for the above Redlands stations. Colorado pikeminnow were very rare in the Gunnison
River samples. In general pikeminnow were more apt to be collected in the higher runoff
years. It also appears that years in which the highest native fish larval percentage and
numbers were produced are also those that produced the most pikeminnow.