7957

• UCREFRP Catalog Number: 7957
• Author: Cranney, J. S.
• Title: Lower Duchesne River Fishery Investigations - 1993 - Draft Report.
• USFW Year: 1994.
• USFW - Doc Type: \
• Copyright Material: NO

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complete passes moving upstream through the selected section were
made with electrofishing gear. An electrical field block was
employed at the upper boundary of the 1/4 mile station. All fish
caught in the first pass were maintained in live cages until
completion of the second pass. All fish were then weighed and
measured and population and biomass estimates calculated. The
previous year a 1/4 mile section in stratum C had been completed
using similar methodology (UDWR unpublished data). -.,.__,
_ ,~
Sampling methods for summer (low flow) electrofishing varied
considerably from those used in higher spring flow sampling. In
reach 1, the same 18 ft. flatbottom boat was used to intensively
sample a 1/4 mile station. An outboard motor was used in the
deeper water and manual propulsion for areas too shallow for the
motor. In stratum B, a canoe was used to transport the generator
and WP units. Electrical power was supplied by a minimum output
2 kilowatt generator and WP~providing pulsed DC current to the
water column.
Opportunistic electrofishing for endangered fishes was conducted on
a limited basis in strata A and B during the low flow period of
late summer. Difficulties in working in deep pools and connecting
shallow riffles, together with access problems on Ute tribal lands,
precluded a niore extensive effort.
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