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 $$$.
Make wise choices based on resources.
South Africa Aquaculture
production methods
Dams, ponds, reservoirs
Tanks (flow through)
Recirculation systems
Net Pen (ocean ranching)
Seapoint Research Aquarium: Cape Town
Good design example: rapid solid concentration and removal
Relative Control &
Production Costs
Dams, ponds, reservoirs: Low control & cost
Tanks (flow through) : Moderate control & cost
Recirculation systems: High control & cost
Ocean pens : ??? High ???
Aquacultured species in SA
Abalone (perlemoen): 260 Rand / kg
Rainbow trout: 31- 35 Rand / kg
Kob: 30 Rand / kg
Yellowtail: 17-25 Rand / kg
Salmon
Tilapia
Prices do not include value added products
Markets for RAS products
Direct to consumer (restaurants,
farmer’s market, on site) pays $$$ 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)
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