[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

FWD: Economics/Sustainability of production



On 12/10/07, Paula Speraneo wrote:

"With almost 200 subscribers to this list, many not in the U.S., where
economics and feasibility of such a system as ours runs into unthought of
obstacles, I believe we should encourage the exploration of all topics
toward that end.  We're trying to find alternative feed sources in Europe
right now to bring the system operating costs more in line with the
economics of Romania."

I agree wholeheartedly! Economics of production is an extremely pertinent
topic in these days when ecosystems and resource bases are under serious
threat. In the USA, the energy which goes into producing farm-raised
catfish FAR exceeds the energy which can then be gotten from the fish. This
seemingly impossible situation is made possible by fossil fuel inputs in
the form of commercial food production and processing, aeration, water
pumping, pond materials production, etc., etc. 

In many -- probably most -- parts of the world, putting more into a food
production system than can be gotten out is simply not possible. Dan
Hemenway's interesting comments about the caloric impracticality of feeding
good meat to fish and the practice of feeding maggots to fish are not
considered unrealistic in Asian fish production systems. In Asia, fish
ponds receive much of their necessary phosphorous and calcium from animal,
human and bird manures, with animal pens and even latrines placed where
effluents reach the shallow, low-trophic (phyto- and zoo-plankton
producing) areas of fish ponds. Economically-important carp have evolved in
concert with dense human populations to survive in polluted waters with
very low dissolved oxygen levels in which catfish, for example, could not
survive. Carp exist for highly-efficient production of food from every
trophic level in a pond, from vegetation-eaters to plankton-eaters to
carnivores (the common bass/bluegill/catfish trio is our southern-US
trophic-ladder equivalent, though vegetation is, sadly, not well-utilized
by this group). 

In Europe, also, many alternative ways of maintaining the aquatic food
chain are practiced, including fertilization with animal and vegetative
'manures'. Ponds are commonly drained during winter months and planted with
edible crops or green manures to reclaim excess nutrients from bottom mud
(the practice of drying pond bottoms can be quite beneficial to pond
health, helping to control many parasites and diseases of fish). In eastern
Europe especially, economics of production dictates that energy out exceeds
energy in, and Paula mentions efforts to adapt scientific production
methods to the extremely 'earthed' economy of Romania. 

These approaches to production, far from being crude, are far more
'scientific' than our methods of producing 100 calories of fish (or corn,
or beef) with several hundreds of calories of high-protein food and energy.
It doesn't take a calculator, a slide rule or even an abacus to figure out
putting more energy into a system than comes out is a failure of sorts,
even if the fish tastes great fried in cornmeal. Using vermiculture systems
to convert human food wastes into high-quality terrestrial fertilizer AND
nutritious fish food, all in one fell swoop, is an excellent move toward
sustainability of production. Cleaning polluted water by using it to water
and fertilize terrestrial crops is another good idea. 

John Todd was mentioned in connection with water purification by biological
means, and his book "Living Machines" discusses this idea in depth.
Dwelling-size waste-purification systems turn out extremely high-quality
water and produce significant amounts of vegetables and fish.

An excellent, science-based fish farming resource which outlines intensive
US fish production methods as well as alternative, low-input,
highly-productive fish raising methods as practiced in Asia and Europe is
"Textbook of Fish Culture: Breeding and Cultivation of Fish" by Marcel
Huet, published by Fishing News, London, 1972. To me this is a "must-read"
for anyone wanting to establish a sustainable fish production system.

I'm really enjoying the expertise and provocative, innovative questions and
ideas from of the members of the list, thanks! Those who were the
'crackpots' yesterday are the visionaries tomorrow!

Jack Rowe