Re: NANFA-- a shocking minnow story

Bruce Stallsmith (fundulus_at_hotmail.com)
Thu, 08 Jun 2000 10:13:47 EDT

Har har, unfortunately that's typical of management agencies. They like to
play God with little idea of what they're dealing with. Coincidentally, at
the EEEF 2000 conference in Athens, GA, last month there was a whole section
of presentations on the need to understand minnow behavior to understand
their ecology. The focus was on southern stonerollers, chubs and _Notropis_
species but obviously pike minnows have much to tell us!

--Bruce Stallsmith
Huntsville, AL

>But the geniuses behind the project obviously didn't study up on minnow
>biology,
>for it's a well-known fact that minnows release a fear scent (called
>Shreckstoff) whenever they're bitten by a predator. This sends a message to
>their schoolmates which says, basically, "Let's get the hell outta here!"
>
>The electrocution device worked for a while, but then the pikeminnow
>abruptly
>stopped entering the ladder. Apparently, the shocked pikeminnow were
>releasing
>their Shreckstoff, which alerted the pikeminnow below the dam that danger
>lurked
>ahead and to stay where they were.
>
>This only served to compound whatever predation problem may have existed,
>because a huge mass of adult (and therefore large--we're talking 3-4 ft)
>pikeminnow congregated below the dam, feasting on whatever salmon
>congregated
>there as well!
>
>The "problem" more or less took care of itself when the dam managers merely
>left
>the gates of the dam open, allowing the passage of migrating salmon
>through the dam. Which, not coincidentally, allowed pikeminnows to complete
>their spawning migration as well.
>
>Suffice it to say, the electrocution device was subsequently removed.
>
>
>
>Christopher Scharpf
>Baltimore

________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

/-----------------------------------------------------------------------------
/"Unless stated otherwise, comments made on this list do not necessarily
/ reflect the beliefs or goals of the North American Native Fishes
/ Association"
/ This is the discussion list of the North American Native Fishes Association
/ nanfa_at_aquaria.net. To subscribe, unsubscribe, or get help, send the word
/ subscribe, unsubscribe, or help in the body (not subject) of an email to
/ nanfa-request_at_aquaria.net. For a digest version, send the command to
/ nanfa-digest-request_at_aquaria.net instead.
/ For more information about NANFA, visit our web page, http://www.nanfa.org