9314 ‎(2)‎

• UCREFRP Catalog Number: 9314
• Author: Wick, E. J. and J. A. Hawkins.
• Title: Colorado Squawfish Winter Habitat Study.
• USFW Year: 1989.
• USFW - Doc Type: Fort Collins.
• Copyright Material: NO

Fish collections
Fish collections for transmitter implantation in Winter 1, were made on
five occasions and were completed by the end of October. Fish were collected
by trammel net, experimental gill net, electrofishing boat, and hook and line
as described in Wick et al. (1985). Netting was conducted from canoe or 18-
foot, flat-bottomed boat powered by an 80-horsepower, Mercury outboard
equipped with a jet shoe. All fish collected were identified and enumerated.
Catch-per-unit-time was recorded for netting and electrofishing samples. All
Colorado squawfish captured were weighed to the nearest 10 to 50 grams and
measured to the nearest millimeter. Colorado squawfish were tagged with
orange Carlin tags supplied by USFWS. Previously tagged Colorado squawfish
(recaptures) retained their original tags.
For the 1987 fall study, eight Colorado squawfish originally implanted in
1986 were radiotracked. In addition, one fish was implanted September 9 at
Maybell RMI 80.8, and three were implanted September 11, at Lily Park RMI 53.2
for radiotracking. An additional six squawfish were implanted in October and
November 1987 for radiotracking during the 1987-1988 winter. Three fish were
tagged in the Government Bridge study area, one at Maybell and two at Lily
Park.
Radiotransmitters (radiotags) used in the first year were supplied by
Custoem'Pelemetry and Consulting. Frequencies ranged from 40.6614-40.7022 MHz.
Ten of twelve tags purchased were implanted, the mining two were used as
test tags. Eight tags had a life expectancy of 18 months and were 4.5
centimeters (can) in length and 1.8 cm in diameter. Four had life expectancies
of 24 months and were 6 can in length and 1.6 cm in diameter. Pulse rates
varied from 28 to 45 pulses per minute. All transmitters were pre-tested and
dipped in sterile, melted beeswax prior to shipping by the manufacturer. Upon
receipt, all tags were started and tested for 2 weeks prior to implantation.
Transmitters used in 1987-1988 were purichased from Smith Root Inc. These tags
had a life expectancy of 12-14 months, were 1.6 cm in diameter, and ranged
from 6.0-8.5 cm in length. Frequencies ranged between 40.687-40.695 MHz with
pulse rates of either 50 or 70 per minute. These transmitters were dipped in
melted beeswax prior to implantation.
Captured adult Colorado squawfish were held in live wells and implanted at
capture sites or they were transported by boat to the implantation site, which
was less than 1.5 miles from the capture site. They were anesthetized with a
solution of tricaine methanosul.fate (MS 222) and surgically implanted with
radiotransmitters according to procedures described by Tyus and Mc.Ada (1984).
Fish were held 10-30 minutes until they recovered from the anesthetic and
released at or near their capture location.
Receivers from three different manufacturers were used during the study;
Advanced Telemetry System's (ATS) programmable scanning receiver, Smith Root's
Model RF40, and Custom Telemetry and consulting's Model CE-12. Fish were
tracked by boat when the main river channel was free of ice using 18-foot
flat-bottomred jetboat or canoe. Once ice formed on the main channel, a four-
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