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

Colorado Squawfish 40:684 (August 4, 1997)
A 24-hour observation of Colorado squawfish 40:684 was conducted on August 4-5, 1997. This
observation was initiated at 1:00pm (1300hr). Fish activity during the next seven hours could be
best described as passive or slow movement. On this particular evening heavy rain began at
about 7:15pm. By 8:45pm most of the rain had ended, however the resulting runoff had created
a plume of high turbidity that ran along the north shore and expanded across the river midway
through the pool containing CS 40:684. As a result CS 40:684 had moved to the south side of
the river in a shallow area of relatively clear water. At 9:45 P.M. the entire pool had become
turbid and CS 40:684 was contacted while moving downstream. At all times during this contact
the crew remained several hundred yards away from the fish (to avoid influencing the fish's
movement due to the artificial lights). The rate of downstream movement by the fish seemed to
average a fast walking pace. By 10:45pm Colorado Squawfish 40:684 held steady in a
backwater pool below an island approximately 0.3 river miles downstream of its initial location.
Although the downstream movement ended, the fish remained very active during the next two
hours. At some point between 12:00am and 1:45am the fish moved to the lower end of this pool.
At 2:45am contact was lost. A private property boundary prohibited the crew from walking
further downstream. Colorado Squawfish 40:684 was relocated the following day at 9:45am
below a sand shelf in a run approximately 1.0 river miles downstream of its initial location.
Shortly after contact was made the fish moved downstream to a deep pool (maximum depth > 10
ft) at river mile 77.3. The fish remained in this pool exhibiting mostly passive movement until
the 24-hour observation had ended at 12:00pm.
Colorado Squawfish 40:502 (August 6, 1997)
Colorado squawfish 40:502 was located at river mile 96.6 on August 6, 1997 and a 24 hour
observation was initiated at 4:00 P.M. (1600hr). This fish exhibited passive movement until
10:45 P.M. at which time it began moving slowly upstream. It passed through a run, then a
riffle, then swam up into a pool at RM 97.1. By 11:30pm the fish was passing through the
upstream end of the pool at RM 97.1. Contact was lost at 11:45 P.M. when the fish left the pool
and continued moving upstream through a run. Miller Ecological crew members moved
upstream to an observation point at approximately RM 97.5. Colorado Squawfish 40:502 was
relocated in a shallow run at RM 97.3 at 12:30am. The fish was still very active, however
upstream movement had slowed to about half of the previous speed. During this time the fish
may have been foraging in the riffle area as it moved slowly upstream. CS 40:502 passed RM
97.5 at 1:50am and by 2:30am contact was becoming weak as the fish was still moving upstream.
Contact was lost at 3:30am. After sunrise (8:00am) CS 40:502 was relocated downstream at RM
96.6 in its original location. The fish remained in this pool habitat through out the remainder of
the 24-hour observation, however it was actively moving within the pool until about 1:00pm.
The 24-hour observation concluded at 4:00pm.
Colorado Squawfish 40:502 (August 20, 1997)
Colorado squawfish 40:502 was located at RM 98.3 on August 20, 1997 (about 1.7 miles
upstream of where it had been two days prior). A 24 hour observation was initiated at 2:30pm
(1430hr). This fish remained mostly inactive until 9:00pm. At this time it moved upstream
Final Report - Colorado squawfish habitat Page 74
Miller Ecological Consultants, Inc. December 17,1997