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

moving (possibly foraging) in the lower end of the run and sometimes in the upper end of the
riffle. CS852 developed a repeated pattern of movement during the night-time hours. This fish
would move laterally along the lower boundary of the run, and at times even move into the upper
part of the riffle. The activity in this area was almost continuous, and would last for 1-2 hours.
This was followed by a period of intense activity where CS852 would move to a shallow area
(depth = 1.9ft., velocity = 2.20) along the south shore. Only passive movement would be
observed there. The fish would remain in this location (apparently resting) for usually less than
one hour, then this process would be repeated. At some time between 4:30am and 6:00am (near
daylight) CS852 moved back into the deep pool about 0.2 river miles upstream. Colorado
squawfish 40:852 exhibited only passive movement until mid-morning. After 11:OOam no
movement could be detected. The 24-hour observation was concluded at 3:00pm.
Colorado Squawfish 40:855 (September 9, 1997)
The second 24 hour observation on CS852 was initiated at 1:30pm (1330hr) on September 9,
1997 at RM 102.4. This fish remained mostly inactive until 8:30pm at which time it moved
upstream into a riffle and began a continuous foraging type actively. The fish moved both
longitudinally and laterally in the river channel and ranged over most of the riffle habitat. This
activity continued until 12:30am at which time the fish became mostly inactive (probably
resting). At 2:30am CS852 resumed the active behavior which continued until sunrise. Between
5:30am and 6:30 am the fish returned downstream to the exact location where it had been
observed "resting" on the previous day. From 6:30am until 12:30pm almost no activity was
observed.
Colorado Squawfish 40:513 (September 23, 1997)
CS513 was located by plane at 8:30am (0830hr) on September 23, 1997 near RM 137.7. Mean
daily discharge was 7,500 cfs and had increased by more than 5,000 cfs over the past three days.
The ground crew moved to the area and began a 24-hour observation. Flow was unseasonably
high and turbid, and this probably had an influence on fish behavior. CS513 spent most of the
morning moving between several locations, but was generally inactive. During the night-time
hours (after 7:30pm) CS513 began actively moving within a circular area along the north side of
the river. This behavior remained throughout the night. The activity consisted mostly of the fish
moving upstream and downstream within a relatively small area at various locations along the
north bank. Near sunrise the activity decreased and CS513 eventually became inactive for the
remainder of the 24-hour observation.
Colorado Squawfish 40:804 (September 24, 1997)
A 24-hour observation of CS804 was initiated at 1:00pm (1300hr) on September 24, 1997. This
fish was located at RM 103.7 in the same place where it had been detected by air two days prior.
CS804 exhibited almost no movement until about sunset. At 9:00pm the fish was actively
moving (possibly foraging) at the lower end of a run 200ft downstream of it's original location.
By 10:00pm contact with CS804 was lost. The area was searched by foot for nearly two hours,
but 40:804 was not relocated. At dawn the crew floated from RM 103.7 down to 95.0 in an
Final Report - Colorado squawfish habitat Page 76
Miller Ecological Consultants, Inc. December 17, 1997