7090

• UCREFRP Catalog Number: 7090
• Author: Archer, D. L., L. R. Kaeding and H. M. Tyus.
• Title: Colorado River Fishes Monitoring Project Final Report.
• USFW Year: 1986.
• USFW - Doc Type: Lakewood, Colorado.
• Copyright Material: NO

Spawning Habitat

The Gray Canyon and Yampa Canyon Colorado squawfish spawning sites were

unique for the Green River systems because of the presence of deep pools and

large eddies adjacent to cobble and boulder bars. Extensive radio-tracking

suggests that the pool areas and eddies are utilized as staging and resting

habitats while the adjacent swift cobble riffles provide suitable substrate

for egg deposition. Though Colorado squawfish have not been tracked to

specific areas with similar habitats, those areas do occur and the capture

of large numbers of larvae downstream of those areas is strong evidence that

spawning is occurring in the vicinity.

The radiotelemetered Colorado squawfish that migrated to the Gray Canyon and

lower Yampa Canyon spawning areas occupied pools and eddies that were 5.0 ft

or more deep with velocities from .5 to 2.6 ft/sec. adjacent to spawning

bars of 3.4-5.0 ft depth and velocities between 1.6 and 5.0 ft/sec where

they periodically moved to spawn.

Table 3. Yampa River estimated spawning period and associated water discharge
and temperature ranges at Maybell guage, RK 140 (RM87).

Date

Discharge (cfs)

Temperature (CO)

20 Jun -
1 Jul -
15 Jul
10 Jul -

20 Jul
20 Aug
20 Aug
20 Aug

1981
1982
1983
1984

437-1578
793-8900a
1010-4990a
954-8240a

18.5-23.0
17.0-250a
18.0-24.5
17 .0-23.5

aRecords for Deerlodge Park at RK 73 (RM 45)

21