Re: NANFA-L-- Electrofishing levels for Darters

John Knight (
Wed, 06 Apr 2005 17:31:40 -0500

these settings depend on your objective. Obviously conductivity is
the first question. The second is are you primarily interested in
releasing all your fish? If you preserving all specimens then I would
recommend following the the recommendations by smith root (for model 12b
POW shockers). You can get this info off their website. Although I
must admit I think the settings they recommend are a bit higher than
anything I would ever use. For that matter I have never actually
shocked-in-the recommended levels by smith-root (so I guess this is bad

O.K. where to start. First of all if you have any issues with
encountering T and E spp. I would simply recommend seining. While they
can be successfully shocked without mortality, it's tricky (plus FWS
really frowns on it). this is not the type of thing I would recomend
over an email.

In streams with conductivity of say 100, if I am targeting darters I
usually shock-in-a voltage of 400 (settings J-4, to start and tweak
there after, check the smith-root charts for specific info). Personally
I pay a good bit of attention to the amps. I can shock these fish
without mortailty issues-in-around 0.25-0.30.

Currently I am working in streams where conductivity rarely exceeds 20.
If you follow the handy dandy smit-root chart you would be using
800-1000 volts. This is silly, in my opinion. I can effectively
collect fish with minimal mortality-in-600, again tweaking the setting
to my liking. Yesterday I think I was on L-6 for example. Again paying
the bulk of my attention to to amps., staying under 0.32 if-in-all

These issues change with depth of course.

I don't know what your objective is, but in my work I am not as
interested in standardizing effort as much as I am in getting the

Perhaps a little more information regarding your objective might help.

John R. Knight

Blackwater et. al FL

>>> 04/06/05 11:49 AM >>>
I am currently doing a big literature search today for specific levels
of frequency, voltage, wattage, cycle, etc. for shocking darters.
Problem is so few papers actually state exactly what they used other
than the blanket statement of the type of equipment they used and the
method. If anyone has any specific settings they use with a certain
model in certain conditions (conductivity) on darters I would greatly
appreciate the information.


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