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

about 20ft and exhibited some passive activity. By 10: OOpm the fish had moved out of the area
and contact was lost. A search was conducted for more than two hours. The area searched
included approximately 300 yards downstream and nearly 1.5 miles upstream of the initial
location, but squawfish 40:502 was not located again until the following morning. At 8:30am on
August 21, 1997 CS 40:502 was found at RM 98.3 in the same spot where it was located at
9:00pm the night before. This fish was fairly active during the first few observations. By
10:30am most activity had ceased, and only passive movement was observed. The 24 hour
observation continued until 2:30pm.
Colorado Squawfish 40:502 (August 25, 1997)
A 24 hour observation was initiated on August 25, 1997 at 1:00pm (1300hr) on Colorado
Squawfish 40:502. This fish was located in a deep pool by a rock point on the north side of the
river. CS 40:502 remained in the deep pool area exhibiting only passive movement until
5:00pm. At this time the fish moved about 50ft. upstream and began moving slowly around
(possibly foraging) in a deep area of slow moving water immediately downstream of another
rock point. This activity ended by 6:00pm and the fish was found nearly stationary immediately
downstream from the rock point in a deep area (5.3ft.) with low velocity (0.1 lft./sec). By
7:00pm CS 40:502 had resumed the slow "foraging" movement at a new location approximately
300ft. downstream. Movement during that time was slow and often circular. At some point
between 7:20pm and 8:00pm the fish vacated the area and contact was lost. At 8:00pm the
surrounding area was searched and at 9:00pm contact was re-established 0.4 river miles
downstream. The squawfish was still moving steadily downstream. The crew followed at a
distance to avoid influencing the fish with artificial light. Contact on CS 40:502 was almost
continuous from 9:00pm until midnight. The fish moved down to the tail end of a run at RM
95.6. This area was shallow (1.4ft deep with a mean velocity of 0.06ft./sec.) and located near the
west shore immediately above a swift riffle. Several times the squawfish approached the riffle
then turned back upstream. This behavior was presumed to be either a foraging behavior or an
aversion for traveling downstream through the shallow riffle. At about 10:45pm the squawfish
(40:502) began moving upstream at a steady fast pace. Contact was lost at times because the
crew could not keep up with the fish. Within a time span of 35 minutes CS 40:502 had moved
upstream a distance of 0.7 miles. Finally the fish slowed and began a more circling type
movement at the upper end of the pool where contact had been originally established (RM 96.3).
At 11:45pm the fish was again moving upstream. Contact was lost by 12:05am. A weak contact
was established at 12:30am at RM 96.6 in a pool about 0.3 miles upstream that indicated the fish
was still actively moving. Due to access problems and the speed of the fish movement, contact
was lost by 1:30am and was not re-established until after sunrise. At 800am Colorado squawfish
40:502 was located in a pool at RM 98.3 (1.7 miles upstream from the last point of contact).
From 8:00am until 1:00p.m. (the end of the 24 hour observation) the fish remained stationary
exhibiting almost no activity.
Colorado Squawfish 40:855 (August 27, 1997)
A 24 hour observation was initiated on August 27, 1997 at 3:00pm (1500hr) on Squawfish
40:852 at RM 102.2. This fish exhibited little activity until evening. At 8:00pm CS852 had
moved from the upper to the lower end of a run. This fish spent most of the night actively
Final Report - Colorado squawfish habitat Page 75
Miller Ecological Consultants, Inc. December 17, 1997