Re: NANFA-L-- conservation and fish farming

dlmcneely-in-lunet.edu
Sun, 07 May 2006 18:18:01 -0500

I have some familiarity, though no technical experience, with
greenhouse culture of tilapia. It is done by some fish farmers here
in Oklahoma. It evidently works well, and conserves water since the
only loss of water from the system is by evaporation, which is much
less than in open ponds. It also avoids discharge of nutrient-rich
water, as the nutrients are taken up by greenhouse plants, some of
which are themselves crops.

I also have some experience with tilapia as an undesirable, invasive
species (I'm speaking here of Oreochromis areaus, blue tilapia, the
species most used in aquaculture in the U.S.). In S. Texas, blue
tilapia has become one of the most common species. It has overrun
almost all surface waters, both natural waters and artificial
impoundments, to the point where one cannot find a water body not
infested with them, usually in immense numbers. The source of this
infestation is fish escaped from aquaculture activity. In Oklahoma,
tilapia occurs sporadically in a power plant reservoir, but does not
get persist in natural water bodies because they are too cold in
winter. Florida, the haven of exotic fishes, is overrun like Texas.
My recommendation to anyone, though I realize that permitting systems
don't always take this into account, is to steer away from any exotic
that has potential for escape and survival.

What is the potential for greenhouse culture of bluegill and other
centrarchids? I realize that they are more pugnaceous toward
tankmates than tilapia, but they are raised outdoors in very crowded
aquacultural setups. What about buffalo, which are ecologically more
similar to tilapia than centrarchids are, and are also produced in
outdoor aquaculture?

David L. McNeely, Ph.D., Professor of Biology
Langston University; P.O. Box 1500
Langston, OK 73050; email: dlmcneely-in-lunet.edu
telephone: (405) 466-6025; fax: 405) 466-3307
home page http://www.lunet.edu/mcneely/index.htm

"Where are we going?" "I don't know, are we there yet?"

----- Original Message -----
From: Bruce Lilyea <lilyea-in-technomaze.com>
Date: Sunday, May 7, 2006 11:57 am
Subject: NANFA-L-- conservation and fish farming
> Sustainable development and poverty reduction have long been areas
> of reading
> and personal research for me. A purported facet of poverty
> reduction is
> teaching people how to provide food for themselves and their
> community. One
> of the approaches that has had some success is aquaponics which
> generatesgrowth in fish and vegetables more rapidly than
> traditional means. One of the
> benefits to using Tilapia in this farming approach is their
hardiness.
> Unfortunately that same hardiness is the reason that so many
> conservationistsare concerned about this species and consider them
> invasive and undesirable.
> Both of these views have high levels of merit. I am interested in
> hearingsome other perspectives on this apparent dilemma.
>
> Bruce Lilyea
> Lakeland, FL
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