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Re: RFP - aquaculture instructional materials




 
> >I have no special knowledge of aquaculture, but I confess I am
> >suspicious about it as a form of "sustainable agriculture."  
First,
> >are we talking marine or freshwater aquaculture?  If marine, then
> >how can an intensive managed production system (aquaculture) begin 
to
> >equal the immense natural productivity of the oceans, which 
captures
> >solar energy on every square foot.  When I asked someone about
> >marine aquaculture feedstock, I was told they are fed rough fish 
and
> >fish waste from deep-sea fishing, plus grain produced on the land.
> >I didn't get an estimate of the ratio.  The point is, shrimp or 
salmon
> >or whatever are most certainly NOT subsisting on the solar input
> >associated with the surface area of their confinement space.  So it 
sounds
> >like maybe the growth of marine aquaculture depends in part on
> >the continuing mining of the wild marine resources AS WELL AS 
industrial
> >agriculture.  Please, TELL ME IT ISN'T SO!
> >
> >Okay, so how about freshwater aquaculture.  In a farm pond, 
integrated
> >with a whole-farm production system, aquaculture sounds good.  
Inputs
> >include residues and wastes as well as maybe some human-edible 
products
> >from the farm.
> >
> >But I am guessing that intensive catfish, trout, tilapia, etc. are 
going
> >to be mostly fed from grain, produced in industrial farming 
systems.
> >Again, please TELL ME IT ISN'T SO.
> >
> >I'm not claiming to be informed, I'm just trying to be a skeptical 
consumer
> >of ideas.  What really sets me off is that this RFP talks about
> >"aquaculture AS sustainable agriculture," not "aquaculture IN 
sustainable
> >agriculture."
> >
> >I hope this comment will lead someone to share insights into these
> >concerns I have with aquaculture.
> >
> 
> 
A farm I am associated with has incorporated a saltwater fish farm 
into its sustainable practices. The saltwater ponds were engineered 
out of mudflats in front of the mangroves, working with natural 
contours, tidal flows, etc. One man did this with one digger, the farm 
covers 5 acres. 
					A system of valves works with natural tidal flows and a channel 
running partway round the entire farm feeds the individual ponds which 
are all graded to allow different depths for different sizes of fish 
and for draining when necessary.
The main species farmed is the grey mullet which were bred from spawn 
caught from the breeding ground in the mangrove - only a small 
percentage at any one time were taken - one man and a large 
'butterfly' net was all that was involved.
					The initial foodstuff was meatmeal which is a natural byproduct 
of the farms meat stock. This was used to feed the algae which is the 
natural food of this species of fish. As the algae became established 
meatmeal was discontinued. At different times other feedstuffs were 
used according to what needed to be recycled and fitted into the 
nutrition needs of the fish farm. For instance feather meal was used 
at one stage, milk powder at another. Nothing is being put in at this 
stage.
 				 Over time other associated water species have found their way 
into the ponds and live harmoniously in this ecosystem. Nets cover the 
ponds to protect against bird predators, and plants natural to the 
site have been re-established. Tests showed the water at the outlet 
into the harbour to be purer than that actually in the harbour - the 
Kaipara Harbour is the second largest natural harbour in the world and 
certainly one of the cleanest. 		
When fish populations begin to increase too fast stock is returned to 
the harbour through the outlet system.
I am not a technically minded person and some of this detail may be a 
little inaccurate but the concepts are pretty much what it is all 
about. The over-riding motivation in setting this up was to show that 
quality protein could be grown sustainably in harmony with the 
existing eco-system and in fact could assist it, which it does through 
water purity, providing breeding areas and restocking the harbour. The 
model has aroused interest in local Maori groups whose traditional 
protein staple was fish. It has also been studied by students wishing 
to help solve problems in third world and developing nations where our 
traditional beef/sheep etc are not appropriate suppliers of protein.
						 I should add that the fish farm is part of a 1,000+ acre farm 
running beef and dairy cattle, plus sheep, tree crops, timber etc and 
a number of  other 'diversified' operations.
It is a commercial scale operation and proves I think that choosing 
the sustainable species (pl) for your locale, relating that to what 
'wastes' are available locally in terms of inputs needed means that 
aqualculture, even 'intensive' saltwater aqualculture is a 
possibility. 
    I believe there are also models in permaculture concepts which 
involve a tiered system of raising small livestock, e.g. poultry, with 
fishponds beneath which are 'fed' by the waste from above. While this 
obviously lends itself to small scale operations it could surely be 
adapted to commercial scale salmon etc farming.