WSP00625

• File Number: 8240.200.10.B
• Description: UCRBRIP Annual Reports
• Basin: Colorado Mainstem
• Date: 1/12/1995
• Author: UCRBRIP
• Title: 1994 Annual Reports Package Part 1
• Water Supply Pro - Doc Type: Publication

speckled dace, and b1uehead sucker, Colorado squawfish (12 specimens)
are represented in each sample and range in size from 18 to 31 rnm TL.

Colorado River, Utah, Spring 1994:

A total of 59 spring monitoring collections for Colorado River Miles 108
to 1,2 were preserved during 4 to 7 April 1994. The collections contain
10,943 preserved fish (an average of 185 specimens per collection)
representing 13 species. About 99.2% of the fish are nonnative. Sand
shiner, red shiner and fathead minnow respectively account for 55%, 23%,
and 21% of the fish. The most abundant of the five native species is
bluehead sucker which accounts for 0.3% of all fish taken but 38% of the
natives, Based on fin ray counts, most of the chubs are probably
roundtail chub; a few might be humpback chub. A total of 19 chubs (28-50
mm TL) were found in eight preserved collections throughout all but the
very lowest end of the monitored reach, but most (89%) were taken above
River Mile 61. A total of three Colorado squawfish (37-44 rnm TL) were
found in three collections (one each), all below River Mile 14.

Aspinall Collections:

Gunnison River, USFWS, Larval Collections, Summer 1993:

All data summarized and submitted. A total of 35 larval-fish collections
for Gunnison River Miles 59.8 to 4,7 were preserved during 3 to 6 August
1993. The collections contain 12,441 preserved fish (an average of 355
specimens per collection) representing 11 species. Catostomids account
for 53% and cyprinids 47% of all fish preserved, About 79% of the all
fish, 87% of the catostomids, and 70% of the cyprinids are native
species. Percentage composition for the more abundant species is 34% for
b1 uehead sucker, 22% for Gil a chubs, 13% for fathead mi nnow, 12% for
flannelmouth sucker, 11% for speckled dace, and 6% for white sucker.
Chubs are probably all roundtail chub; individual measures to the nearest
millimeter and fin ray counts were not recorded. No Colorado squawfish
or "obvious" razorback suckers were identified. There is a very slim
chance that some of the fish identified as flannel mouth sucker or
categorized as unidentified suckers might actually be razorback sucker,
but such is not morphologically obvious. Two specimens are tentatively
identified as 10ngnose sucker and more probably are represented in the
category of unidentified suckers along with probable hybrids. Non-
cypriniform fish are represented by a solitary plains killifish.

Gunnison River, USFWS, Voung-of-the Year Juvenile Collections, Fall 1993:

All data summari:zed and submitted. A total of 56 young-of-the-year
collections for Gunnison River Miles 59,7 to 9,5 were preserved during 7
to 10 September 1993. The collections contain 23,575 preserved fish (an
average of 421 specimens per collection) representing 12 species. About
58% of the fish are native species, 15% of the cyprinids and 43% of the
catostomids. Catostomids account for 51% and cyprinids 48% of all fish
preserved. Percentage composition for the more abundant species is 30%
for b1uehead sucker, 25% for fathead minnow, 13% for f1annelmouth sucker,
8% for speckled dace, 7% for Gila chubs, and 7% for white sucker. Chubs
are probably all roundtail chub; individual measures to the nearest
millimeter and fin ray counts were not recorded. No Colorado squawfish

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