7153

• UCREFRP Catalog Number: 7153
• Author: Holden, P. B.
• Title: Study of the Habitat Use and Movement of the Rare Fishes in the Green River, Utah.
• USFW Year: 1978.
• USFW - Doc Type: Logan, Utah.
• Copyright Material: NO

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The primary objectives of the study were:
1. Determine the physical and chemical parameters of the
habitats used by all sizes of rare fishes with emphasis
on young fi shes.
2. Determine the movements of the rare fishes, especially
young-of-the-year.
3. Deternrlne the other fish species associated with the rare
sped es .

METHODS
The study area was the Green River from Jensen, Utah to Green
River, Utah, a distance of 175 miles (Figure 1). The area from.
Jensen to Sand Wash was sampled from August 5 to August 20, 1977,
and the area Sand Wash to Green River (Desolation and Gray Can-
yons) on September 7-14 and 22-26, 1977.
Velocity, depth, temperature, and substrate type were mea-
sured in each habitat sampled for fish. Habitats were categorized
as backwaters, eddies, runs, and riffles. Current velocity was
measured in the part of the habitat where velocity was most repre-
sentative of that area. A March-McBirney model 201 portable water
current meter was used to measure velocity to the nearest 0.1 foot
per second. Maximum depth of the area was recorded to the nearest
inch using a graduated wading rod. Substrate type was recorded
as silt, sand, gravel, or cobble, or combinations and was eval-
uated visually. The silt category was subdivided into soft silt

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