7245

• UCREFRP Catalog Number: 7245
• Author: Rose, K. L. and D. R. Hann.
• Title: Consolidated Instream Flow Report, Habitat Modeling on the Green River Using the Physical Habitat Simulation System.
• USFW Year: 1989.
• USFW - Doc Type: Grand Junction, Colorado.
• Copyright Material: NO

Table 1.

Phenology chart for rare and endangered fish known to inhabit
the Green River (segment 3, river mile 248.1 to 345.0).

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Life stage

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Colorado squawf;sh
1. Adult Jan
2. Young-of-year nursery
3. Juvenile Jan
4. Spawning
5. Migration

Razorback sucker
1. Adult Jan
2. Spawning

Humpback chub
1. Adult Jan

Dec
Nov 1.
Dec

Mid-Jul

Mid-Jun
Mid-May

Sep

Oct

Dec

Apr

Jul

Dec

334.0 (represented by the Ruple Ranch study site), and sub-segment B from RM
294.8 to 309.8 (represented by the Quarry study site), were selected as study
site locations (Figure 1) because of their biological importance. The Ouray
study site (RM 259.0) was selected to quantify changes in backwater habitat
for young-of-year Colorado squawfish.

Species distribution for the Green River has been determined from
radiotelemetry, catch data, and other information (Tyus et. al 1987). This
information concludes that adult Colorado squawfish occupy a variety of
habitats including eddies and runs throughout this reach year round. During
the pre-spawning period when water temperatures range between 16 and 20
degrees Centigrade (C), adult squawfish move through this area to specific
spawning grounds. Young squawfish are abundant soon after the spawning period
in backwater habitats. Little is known about the life history of the
razorback sucker, however, collections of ripe males in this area has resulted
in classification of this reach as a suspected spawning area.

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