8206

• UCREFRP Catalog Number: 8206
• Author: Miller, W. J. and D. E. Rees.
• Title: Colorado Squawfish habitat use and movement during summer low flow in the Yampa River upstream of Cross Mounatin Canyon. Final Report.
• USFW Year: 1997.
• USFW - Doc Type: Fort Collins, Colorado.
• Copyright Material: NO

Ecological Consultants crew on September 11, 1996 and confirmed by ground crew that day.
CS781 remained in this same habitat throughout the remainder of the study (Figures 4 and 5).
Immediately after locating CS781 on September 11, 1996, a 24 hour observation was conducted.
The fish appeared to move only slightly during this time (Figure 6). CS781 was located in the
exact same position (RM 89.8) during each following observation week during the study. It is
likely that this fish either expelled the transmitter or was dead. Data from this fish was not used
in the analysis.
Colorado Squawfish #40:7419 (CS741)
CS741was captured by angling at RM 82.7 on August 27, 1996. This fish was located on at least
12 separate occasions and was never found more than one river mile from the capture location
(Figures 7 and 8). CS741 was almost always located in one of the two large pool habitats within
this area. The only exceptions were when it was found in an eddy along the lower edge of one of
the large pools, and when it was found in a run at the head of the other pool. These two large
pools were unique because each had a submerged shelf in deep slow moving water. The lower
pool had a bedrock shelf and the upper pool contained a submerged sandbar. CS741 was usually
in one of these two habitats. Although the pools were separated by more than 0.3 miles of run
and riffle habitat, CS741 was not tracked within this area during monitoring periods.
A 24 hour observation was conducted on CS741 beginning at 9:15 a.m. on October 23, 1996
(Figure 9). During the daylight hours CS741 was mostly inactive, changing position just once.
CS741 became moderately active after sunset then changed habitats prior to 10:15 p.m. when it
was located in an eddy pool about 700 feet downstream. Contacts made after 10:15 p.m.
indicated that CS741 was very active within a 20 foot area of that eddy pool. This activity
continued until 1:15 a.m. on October 24, 1996 when the fish became mostly inactive. CS741
remained stationary and inactive throughout the remainder of the 24 hour observation.
Colorado Squawfish #40:6840 (CS684)
CS684 was captured by angling on August 27, 1996 immediately below the sandbar shelf in the
upper pool used by CS741 at RM 83.0. Early contacts suggested that shortly after it was
implanted it moved downstream. The day after its release it was located near the submerged
bedrock shelves in the pool with CS741 at RM 82.7. Twelve days later CS684 was located in a
large, deep pool at RM 77.3 (Figures 10 and 11). It had moved over five miles downstream
during the lowest flows of the summer. The pool and run complex at RM 77.3 was nearly 0.3
river miles long. The run was deep and slow moving. It drops off into the pool formed at a river
bend. Maximum depth in the pool was estimated at 15 feet, but specific structures or habitat at
the bottom of the pool could not be determined. CS684 was found in a variety of locations in
this pool and run habitat. A 24 hour observation was never conducted on CS684 in 1996 because
of lack of permission to access private land.
CS684 was contacted by air on May 23, 1997 at RM 77.3 in the same deep pool this fish had
been in the previous fall. Contact was made again on July 23, 1997 at RM 77.3 (Figure 12).
This fish stayed at this location for most of the tracking period. On two occasions it moved
approximately one mile upstream.
Final Report - Colorado squash habitat Page 8
Miller Ecological Consultants, Inc. December 17,1997