9348

• UCREFRP Catalog Number: 9348
• Author: Crane, H. S.
• Title: Fishery Investigations of the Glen Canyon and Flaming Gorge Impoundment Areas.
• USFW Year: 1959.
• USFW - Doc Type: \
• Copyright Material: NO

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Creek in January 1959 (Table 6). At this time large masses of ice were
floating in the water.
Table 6 presents the results of chemical tests conducted on the Colorado
River. No chemical conditions were detected which would be deleterious to
fish. The dissolved oxygen (D.O.) concentration was fairly high, ranging
from 7.2 ppm to 13..4 ppm. The winter samples showed a higher D.O. concen-
tration, due no doubt, to the greater solubility of oxygen in cold water.
Tti~renty-four hour "runs" showed only slight fluctuation in the D.O. concen-
tration. This probably indicates a relatively small plankton population
and dearth of organic material, but might also be due, at least in part,
to the constant circulation of the water which would tend to bring it
into equilibrium with the atmosphere. The wide diurnal.fluctuation in
carbonates (C03=) is rather puzzling; although an increase in C03= concentra-
tion due to photosynthesis often occurs during the afternoon, there appeared
to be no definite pattern to the C03= variation in the Colorado River.
Doubtlessly diurnal changes and variations in flaw occurring in the waters
of the tributary streams exert an influence on the chemistry of the Colorado
River, and may account for some of the unusual-conditions observed. Generally
the total hardness of the river water increased as`it approached the damsite.
Carbon dioxide (G02) was either absent or present in only trace amounts, and
in none of the samples did it exceed 3 ppm.
Limnolo~.y of the Tribuary Streams
As was mentioned previously, most of the streams tributary to the
Colorado River in the Glen Canyon area are of intermittent nature and sub-
ject to wide seasonal and yearly fluctuations.
In many of the tributaries a small clear stream originating from springs
or seeps may exist near the mouth of the canyon during all or part of the
year. Further up the canyon the stream bed may be dr~r excet~t during ne.r;_od4
of high runoff when the entire stream bed is often filled with a torrent of
muddy water. As the river recedes during the summer, muddy backwaters are
often left at the mouths of the tributaries.
The chemical and physical conditions in the tributary streams are
summarized in Tables 7 and g. With the exception of periods of flood condi-
tions, there appears to be little seasonal difference in the chemical and
physical characteristics of the streams. Most of the spring-fed streams
are very clear, with a turbidity of from 2 to 5 pin and a volume of less
than 1 c.f.s. Water temperatures were found to be quite variable, ranging
from 44° at.Tr~chyte Creek in January 1959 to a high of 92° F. recorded
in Bullfrog Creek during July, 1958