7256

• UCREFRP Catalog Number: 7256
• Author: Radant, R. D., et al.
• Title: Colorado Squawfish Investigations - White River, Utah.
• USFW Year: 1983.
• USFW - Doc Type: Salt Lake City, Utah.
• Copyright Material: NO

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mercury battery having a theoretical life of ISO days for AVM modules and

150 days for Smith-Root modules. The units transmitted in a frequency

range from 40.660 to 40.700 MHz. A Smith-Root SR-40 "search" receiver

was used to scan for all emitted frequencies, then a Smith-Root RF-40

receiver was used to identify the specific frequency transmitted. A

Larson-Kulrod whip antenna was used to search for implanted fish and a

directional loop antenna to triangulate fish location.

A 16-ft (4.9-m) flatbottom boat powered by an lS-hp outboard motor

was used in radiotelemetry and intensive sampling efforts.

Drift nets used to collect larval fishes were constructed with

1/32-in (O.S-mm) bar mesh netting and had an IS-in (46-cm) by 12-in

(30-cm) rectangular opening. The nets were 43 in (109 cm) long with a

removable PVC bucket attached to the cod end.

Hand seines measured 3.3 ft (1 m) by 2.5 ft (O.S m) and were made

with 1/32-in (O.S-mm) bar mesh netting.

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Study Procedures

Between 25 May and 2 July extensive electrofishing was conducted

throughout the study area to collect adult Colorado squawfish for radio

transmitter implantation. Only fish larger than 450 mm total length (TL)

were considered for transmitter implantati~n. Each Colorado squawfish

captured was weighed, measured and a numbered Carlin tag attached. Water

depth, velocity, substrate type and habitat type were recorded where the

fish was first observed. Fish selected for radiotelemetry monitoring

were anesthetized with MS-222, and radio transmitters surgically

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