7055

• UCREFRP Catalog Number: 7055
• Author: Archer, D. L., L. R. Kaeding and B. D. Burdick.
• Title: A Study of the Endangered Fishes of the Upper Colorado River.
• USFW Year: 1985.
• USFW - Doc Type: Grand Junction, Colorado.
• Copyright Material: NO

LIST OF FIGURES

Fiqure

1. Map of the Colorado River study area (upper). The stippled areas
are canyons that separate the lower (reach 1), middle (reaches 2
and 3), and upper (reach 4) study reaches of the river. Numbers
are river-mile distances upstream from the confluence of the
Colorado and Green rivers. Arro~s indicate direction of river
flow. Belo~ is a diagramatic representation of the river profile
sho~ing gradient and mean depth.

2. Movement of radio-tagged Colorado squa~fish of adult size in the
Colorado River, 1982-84. Numbers designate individual fish
(refer to Tables 1-3). Asterisks indicate the occurrence of
radiotagged fish in the 'two-mile reach of the Gunnison River,
downstream from the Redlands Diversion structure.

3. Relative abundance of larval Colorado squawfish ~ithin pooled
samples collected by 0.5-IIIIl-mesh hand seine from lo~-velocity
habitats in 10-mile reaches of the Colorado River, Utah and
Colorado, 1982-1984. Shaded areas indicate that samples were
taken but larval Colorado squa~fish were not collected. Size of
the dot is related to the percentage of larval Colorado squa~fish
in pooled samples as follo~s: iI', · ; 1 to 5', · ; 5 to 10',
10 to 2~, . ; 20 to 301,. ;and )30', ...

4. Accumulated degree days exceeding 12 C (upper) and 20 C (lower)
in the upper Colorado River study area,determined from maximum-
daily water temperature at the USGS gage at the Colorado-Utah
border, 1982-1984. Estimated beginning and ending spa~ning dates
(see Table 5) are indicated by vertical bars; dates for the peak
of spa~ning (when the median 50' of the captured larvae were
estimated to have been spa~ned) occur between the triangles. .

5. Mean-daily discharge of the upper Colorado River at the USGS
gage near the Colorado-Utah border, 1982-1984. Estimated
beginning and ending spawning dates (see Table 5) are indicated
by vertical bars; dates for the peak of spa~ning (when the median
5~ of the captured larvae were estimated to have been spa~ned)
occur at the arro~s. .

6. Mean catch per effort (fish/10 m2) for post-larval, age-O
Colorado squa~fish collected by 6-mm-mesh seine from backwaters
in 10-mile reaches of the Colorado River, September, 1982.

7. Mean catch per effort (fish/10 m2) for post-larval, age-O
Colorado squa~fish collected by 3-mm-mesh seine from backwaters
in 10-mile reaches of the Colorado River, September and October,
1983.

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