Transcript Slide 1

Using Recirculating Aquaculture
in South Africa – Business Sense
Daniel Miller
[email protected]
Florida A&M Univ.
Farmer to Farmer
Stellenbosch,
South Africa
Feb. 2010
Upon the completion of this lesson
participants will be able to:
 List and describe 4 types of production
methods used in South Africa
 List the relative cost of production for each of
the 3 methods.
 Compare the value of species produced in SA.
 Identify 3 markets and which ones pay $$$.
 Make wise choices based on resources.
South Africa Aquaculture
production methods
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Dams, ponds, reservoirs
Tanks (flow through)
Recirculation systems
Net Pen (ocean ranching)
Seapoint Research Aquarium: Cape Town
Good design example: rapid solid concentration and removal
Relative Control &
Production Costs
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Dams, ponds, reservoirs: Low control & cost
Tanks (flow through) : Moderate control & cost
Recirculation systems: High control & cost
Ocean pens : ??? High ???
Aquacultured species in SA
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Abalone (perlemoen): 260 Rand / kg
Rainbow trout: 31- 35 Rand / kg
Kob: 30 Rand / kg
Yellowtail: 17-25 Rand / kg
Salmon
Tilapia
Prices do not include value added products
Markets for RAS products
 Direct to consumer (restaurants,
farmer’s market, on site) pays $$$ but it
is a smaller market.
 Wholesaler pays $$...moderate volume
 Processor is the largest market, good for
cash flow, but pays $.
Autotrophic vs. Heterotrophic
 Nitrifying autotrophic bacteria are
everywhere. (ubiquitous)
 Solid waste in the system water will allow
heterotrophic bacteria (not good) to
compete with nitrifying autotrophic
bacteria (good) in the biofilter.
 Remove solids ASAP
Brown Blood Disease
 Caused by high levels of nitrite in the
system water.
 Nitrite competes with oxygen for uptake
in the gills of fish.
 Fish develop brown gill tissue (brown
blood)
 Chloride ions (NaCl @ 20 mg/l) will
reduce nitrite toxicity on fish.
RAS Fill-up to Start-up
(6 months)
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Protect biofilter from sunlight
Stock 6 to 8 weeks after adding water.
Use experienced biomedia to jump start.
Spike water with ammonium nitrate.
Monitor NH3 and Nitrite spikes
Verify NH3 conversion rate / day
Avoid major changes in feed / temp
Monitor closely during first 6 months
with analysis. Keep records!
Good Business Choices
 Choose a low cost method of production
 Start small, learn, begin local marketing
for highest price. Set your product apart
from the rest.
 If RAS is chosen as method, maximize
value of product. (elec. cost is high % of
operational cost)
 Smaller fish (fingerlings) have more
value per kilogram
Where is the trout?
 Stellenbosch restaurants sell to affluent
diners (tourists).
 Restaurants require weekly deliveries.
 Restaurants pay highest price to farmer (for
dead fish).
 Recreational market pays high price but it is
very limited.
Appropriate Use of RAS in SA
 Research for studying new species
 Production of fish fingerlings for growout
market
 Abalone (perlemoen) production
 Conservation of water / land resources.
 Quarantine / post harvest use.
Additional Resources
 A Fish Farmers Guide to
Understanding Water Quality:
http://darc.cms.udel.edu/AquaPrimer/wqualityas-503.pdf
 Aquaculture Network Information Center:
www.aquanic.org/oindex.htm
 Southern Regional Aquacultural Center (SRAC)
www.srac.com
 Aquatic Eco-Systems – www.aquaticeco.com