7834

• UCREFRP Catalog Number: 7834
• Author: Burdick, B. D. a. R. B. B.
• Title: Experimental Stocking Of Adult Razorback Sucker In The Upper Colorado And Gunnison Rivers.
• USFW Year: 1997.
• USFW - Doc Type: \
• Copyright Material: NO

1. determine movement, distribution, and dispersal patterns of razorback
sucker released in the river,
2. determine survival and habitat use following stocking,
3. determine movement of radio-tagged fish prior to- and during the
spawning period to evaluate potential spawning and to identify
potential spawning areas,
4. determine the usefulness of pond-reared fish for augmenting or
restoring wild populations,
5. determine the utility of using a very small number of fish to
experimentally evaluate restoration or augmentation potential, and
6. provide recommendations for the number and size for stocking razorback
sucker to augment or restore razorback sucker populations.
STUDY AREA
The study area was the Upper Colorado River from Rifle, Colorado,
downstream to Westwater Wash (river mile [RM] 241.0-125.0) and the Gunnison River
from Hartland Dam near Delta, Colorado, to the confluence with the Colorado River
(RM 60.0-0.7). Both stream reaches are within critical habitat for razorback
sucker.
METHODS
Adult razorback sucker' were captured from Etter Pond with trammel nets in
early-April 1994. Adult razorback sucker were surgically implanted with 4.5-year
radio transmitters. Advanced Telemetry Systems (ATS°) radio transmitters were
equipped with an internal loop antennae, powered by a lithium battery, emitted
a unique signal in the 40 Mhz frequency band, and weighed 27 g. The transmitter
had a microprocessor chip to emit a signal for 12 h and be "asleep" or off for
12 h. This increased tag life expectancy to 4.5 years. Transmitter weight was
no more than 2.8% of fish body weight. Following capture, all fish were held in
a holding tank with 0.5% salt (by weight) solution. Fish were then anesthetized
with MS-222, weighed (g), measured (total length [TL], mm), muscle-plugged for
genetic analyses, and PIT-tagged. Implanted fish were injected with an
antibiotic, Gentocin (0.5 ml/2 k body weight). Surgical procedures for
implanting the radio transmitters followed that of Hart and Summerfelt (1975) and
Tyus (1984). Following surgery, fish were held in a holding pen in Etter Pond
for 24 h to recover. Fish were transported in a 225-gallon tank with 0.5% salt
by vehicle to the stocking sites. Fish were stocked immediately into the river.
One razorback sucker was implanted with a non-functional radiotag and held
in a pond at Horsethief State Wildlife Area (SWA) for observation. In March
1 Geneticists determined that razorback sucker from Etter Pond were 'pure' razorback sucker.
3