7333

• UCREFRP Catalog Number: 7333
• Author: Valdez, R. A. and W. J. Masslich.
• Title: Winter Habitat Study of Endangered Fish - Green River, Wintertime Movement and Habitat of Adult Colorado Squawfish and Razorback Suckers.
• USFW Year: 1989.
• USFW - Doc Type: Report No. 136-2 for Bureau of Reclamation,
• Copyright Material: NO

Dates
Year1
(1986-87)

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Table 2. Purpose and dates of field trips conducted for the Winter Habitat Study.

Purpose

Year 2
(1987-88)

Capture Fish and Implant Transmitters
Capture Fish and Implant Transmitters
Reconnaissance Tracking
Tracking and Monitoring Trip #1
Tracking and Monitoring Trip #2
Tracking and Monitoring Trip #3
Tracking and Monitoring Trip #4
Tracking and Monitoring Trip #5
Tracking and Monitoring Trip #6

October 9-17
October 25-30
November 13-18
December 2-11
January 5-1
Jan 28 - Feb 6
February 15-23
March 9-17
March 23-31

October 5-14
October 20-29
November 18
December 1-10
January 5-14
Jan 25 - Feb 3
February 15-24
March 8-17
March 22-31

radiotram;mitters. Other endangered fishes
were weighed, measured, lagged and released,
including Colorado squawfisl1 and razorback
suckers considered too small for surgical
implant. No humpback chub (Gila cypha) or
bonytail (Gila e/egans) were captured during
this investigation.

All fish species were counted and released,
while actual electrofishing time was recorded in
seconds on the intemal WP-15 timers, and
used in calculating calch per unit effort (CPE)
as numbers of fish per 10 hours. Pertinent
data were recorded on forms provided. by the
FWS, and compatible with their database
management system, dBASE 111+.

Since the study area included f1atwater and
whitewater regions, aluminum jonboats and
whitewater rafts were used. The jonboats were
16 feet long, and powered by 25 or 35 hp
Mercury outboards. One 14-foot jonboat with
a 9.9 hp outboard was stored at Echo Park
because winter road conditions often prohibited
trailoring a boat into the area.

The rafts included 17 and 18-foot Riken
Havac;us equipped with rowing frames for
whitewater and XD-25 hp Mercury outboards for
f1atwater areas. A 16-foot jonboat and the 18-
foot Havasu raft were equipped with
electrofishing systems which were removed
during tracking.

3.2 Implanting The Radiotransmitters

3.2.1 Radiotransmitters and Receivers Used

Radiotelemetry was used to locate anrt follow
movements of adult Colorado squawfish and
razorback suckers. Twenty radiolransmitters
(fish modules). were provided by FWS durinq
year 1; 10 manulactured by Smith-Root (model
PAO) and 10 manufactured hy AVM (model
SM-1). The Smilh-Rool and AVM transmitters
were powered by lithium and mercury batteries,
respectively, each with a 12 to 14-montl1 life
expectancy. For year 2, 20 Smith-Root (P-40)
radiotransmitters were purchased by BIO/WEST
because of the more favorable performance of
this product during year 1 (See Appendix F).

The transmitters used in this investigation
operated within Ihe 40.660 to 40.700 MHz
range, with. transmission rates of 40 to 80
pulses per minute. All transmitters were tested
for pulse and frequency upon receipt from Ihe
factory. and each was dipped in melted
beeswax prior to implantation to minimize
negative reaction by the peritoneum and
internal organs of the recipient fish. Pulse and
frequency were rechecked prior to and
immediately following implantation 10 record any
variation in frequency or pulse from factory
specifications, and to minimize Ihe difficulty in
locating lransmiUer signals during tracking.

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