9304

• UCREFRP Catalog Number: 9304
• Author: Mueller, G., L. Boobar, R. Wydoski and K. Comella.
• Title: Aquatic Survey of the Lower Escalante River, Glen Canyon National Recreation Area, Utah; June 22-26, 1998.
• USFW Year: 1998.
• USFW - Doc Type: \
• Copyright Material: NO

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Length, weight, and range data taken from fish collected in the Lower Escalante
River, Utah during June 22-26, 1998.
# x Length (mm) (Range)
41 144 (36-400)
14 196 (83-313)
36 56 (36-84)
88 52 (32-78)
9 50 (44-54)
1 440
2 77 (72-82)
1 172
8 73 (45-137)
1 600
1 62

Table 2.3.

Species
FlanneImouth sucker
Roundtail chub
Specked dace
Red shiner
Fathead minnow
Carp
Channel catfish
Yellow bullhead
Green sunfish
Striped bass
Brown trout

DISCUSSION

# x Weight (gr) (Range)
18 98 (6-320)
12 98 (25-275)
o
o
o
1
o
1
o
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o

1,000

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1,650

Habitat-- The dissimilarities in habitat reflected three, distinct fish communities. As reported by
Holden and Irvine (1974) there is a distinct change in both stream morphology and community
structure between the middle and lower portions of the Escalante River. Habitat complexity and
amplitude of hydraulic cycles must have a significant influence on fish community structure.
The middle canyon represents a fairly broad floodplain which is typically channelized by a well
developed riparian corridor bordered by willow, cottonwood and tamarisk. The combination of
bank cutting and well developed riparian corridors provides ample overhead cover in the form of
vegetative shade and exposed roots mass where fish can hide from predators, feed, spawn, or find
refuge from the current. There is abundant evidence that high flood flows frequently swell and
overbank, inundating seasonal side channels. The occurrence of woody vegetation, large snags,
and piles of flood debris on higher benches of the floodplain would provide ample cover for fish
during floods. The river was relatively shallow with few areas deeper than 1 m. Any habitat that
could be categorized as pool, were extremely small with depths never exceeding 1.5 m.
Typically, the stream was channelized with a mixture of undercut and gravel banks.

Downstream of Scorpion Gulch, the river enters and travels through a narrow and confined
canyon to Lake Powell. The river has an entrenched channel. Vegetation was absent or
extremely rare, being limited to young stands of willow, tamarisk, and weeds. The stream bed
was strewed with large boulders, rock rubble, and fines. Cover was typically limited to rock
interspace and deep pools caused by river hydraulics and rock outcroppings. During flooding,
the canyon would pose extremely hostile conditions. The hostile environment may benefit
endemic species by negatively impacting nonnatives.

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