7346

• UCREFRP Catalog Number: 7346
• Author: Wick, E. J. and J. A. Hawkins.
• Title: Colorado Squawfish Winter Habitat Study, Yampa River, Colorado 1986-1988.
• USFW Year: 1989.
• USFW - Doc Type: Fort Collins, Colorado.
• Copyright Material: NO

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wheel-drive truck was used on ranch roads for tracking where possible.
Otherwise, fish were tracked on foot between vehicle access points. Because
of heavy snows during Winter 2, m mobiles, srw;wshoes and skis were used to
track along the river.
During Winter 1, contact was maintained after implantaticn by tracking in
October and November. Fran December through march, fish were tracked
systematically on a bi-weekly schedule (Table 1). The two groups of five fish
each (Government Bridge and Maybell) were alternated as target and non-target
groups on each trip. During each trip, four fish from the target group were
monitored for 2.5 hours (hrs) in each of the following 6-hour (hr) periods:
morning (0600-1200 hrs), afternoon (1200-1800 hrs), evening (1800-2400 hrs),
and night (0000-0600 brs). In addition, a fifth fish from the target group was
observed for a full 24hr period on each trip. During mid winter, on trips 5
and 6, two fish were monitored for 24-br periods. In addition, during each bi-
weekly trip all fish in the non-target group were monitored for at least 30
minutes and usually up to 2 hrs if time permitted.
Fish were initially detected using 1/2 or 1/4 wave whip antennas mounted
on a boat, four-wheel-drive vehicle, snowmobile, or hand carried. Once
detected, the fish location was triangulated using a Smith Root directional
loop antenna according to methods described by Tyus (1988). Survey flags were
placed along the bank marking each transect line. Tansects were then checked
every few minutes to determine if the fish remained along the same transacts
and thus in the same location. If a fish remained in the same location for 15
minutes, it was given a map location designation on bath a field form and a
habitat map depicting key features s and fish locations within the area. Target
fish Were then observed for an additional 2-3 hrs in 5-20 minute intervals.
Habitat criteria were measured at all sites at which fish spent at least 30
minutes. Fish being tracked for the full 24 hr period were similarly observed
until a preferred site location was determined, then triangulation was
conducted at least every hour to determine if any major movement or location
Change occurred over the 24hr period. If more than one radiotagged squawfish
were present in an area, data were gathered simultaneously on all fish present
with the scheduled fish taking priority.
During the observation period, data recorded on field data sheets
included radiatransmitter frequency, pulse rate, signal strerqjth, weather, air
temperature, river mile location, habitat type, presence of ice Waver, time of
each triangulation, actual contact duration, movement type, site location
recorded an a habitat sketch (map ID), and pr?ee and distance from other
radictagged fish (Appendix B). Habitat type was divided into primary and
specific habitat types. Primary habitats were main channel, side channel, and
tributary stream. Specific habitats included shoreline, eddy, embayment, run,
backwater, pool, riffle, and rapid (Appendix A). Fish movement was designated
as either stationary, active, local or moving. "Stationary" was used if no
change in fish location could be detected between or during fish observation
periods. A fish was noted as "active" if its location changed within a 5-n-
diameter circle over its original location, as long as the specific habitat
used remained the same. "Local" movement was designated if a fish moved to a
new location outside the original 5-m-diameter circle about its original
location but within the same specific habitat. The "moving" designation was
used if a fish was observed in the process of moving to a new location or had
moved to a different specific habitat type regardless of distance (i.e., fish
moved from eddy to run or from one eddy to another eddy) .
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