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>Date: Mon, 2 Dec 1996 14:40:55 -0800
>From: Craig Fusaro <[log in to unmask]>
>Subject: Electroshock procedures
>
>"Do (sic) to the irregular or rocky conditions electrofishing may be
>required... Fish will be collected using pulsed direct current with
>voltage set at 200-300 volt and 0.1 to 2.0 amps output... Pulse frequency
>and pulse width will be set to induce involuntary swimming action with
>minimum harm to fish."
>
>1. Is electrofishing really effective in five to ten foot water depth?
>
>2. Are the pulse voltage and current settings specified appropriate for
>these water depths?
>
>3. Would mortalities reasonbly be expected under the regimen described
>above, and, if so, what could be expected in terms of percent deaths?
>
Pulsed direct current electrofishing from a boat is definitely the safest
method from the fish's point of view. We have had considerable success
using our boat-mounted electroshocker (Model 7.5 GPP, Smith-Root, Vancouver,
Washington) in river water 5-10 feet deep. In fact we were pulling 6-8 lb
steelhead out of the Columbia River a couple of years ago. The key to
effective electrofishing is knowing the conductivity of the water you will
be fishing. We have fished with 900 W (300 volts at 3 amps) without any
significant mortality to larger fish. Keep in mind, however, that many of
the potential adverse effects of electrofishing are manifested over a
relatively long period of time. Since most of our work has been
catch-and-release, we have been unable to calculate a true mortality rate.
Good luck!
Tad Deshler
Tetra Tech, Inc.
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