Drift nets are rectangular, fine mesh (350u) nylon nets. Standard size is
12x18" mouth and 40" length. Drift nets have a reinforced frame at the
opening that is anchored into the stream bottom with stakes (like long tent
stakes). They work on the same principle as a Wisconsin plankton net, or a
Surber net, excpet that they remain at a fixed location. By measuring depth
of water at the opening and measuring flow, you can use collections to
estimate density of organisms passing through the net (e.g., number/m3).
-----Original Message-----
From: Bruce Stallsmith
Sent: Tuesday, June 05, 2001 3:53 PM
To: nanfa_at_aquaria.net
Subject: RE: NANFA-- ichthyology's not that bad... really!
>Off the top of my head, I do not know of any other references (although I
>am
>sure they must exist). I thought that Art Brown had done one other study
>of
>drifting larvae. A lot of drift nets, however, are set by aquatic
>entomologoists having limited interest in larval fish, so a lot of drifting
>larvae (including darters) may go unrecorded.
>
>- Jan
I've never done any work with drift nets. How do they work, and are they
usually home-made or off-the-shelf? I realize that I could use one (or
more!) in my observations of stoneroller YOY.
Speaking of which, yesterday in our collection we caught some YOY that are
~25 mm long and have entered the juvenile stage (the "we" is I have a
student working with me for Special Topics credit). They look like real
little fish, with a forked tail and prominent lateral black band.
--Bruce Stallsmith
Huntsville, AL
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.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/----------------------------------------------------------------------------- /"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