seaweed paddle pond systems
DESCRIPTION
Following on from a successful presentation to the Reciculation council members earlier in 2004, I was asked to make this presentation which should be titled why abalone farmers should grow seaweeds.TRANSCRIPT
SEAWEED PADDLE POND SYSTEMSSEAWEED PADDLE POND SYSTEMS
• Mixed diet gives better growth rates Mixed diet gives better growth rates • MSY of kelp bed reached in 2002 MSY of kelp bed reached in 2002
– Potential Potential over-harvesting over-harvesting – Decrease in epiphyte densitiesDecrease in epiphyte densities
• Limited suitable coastal areasLimited suitable coastal areas• ‘‘HAB’s’HAB’s’ • RecirculationRecirculation• IIntegration will improve water qualityntegration will improve water quality
Why cultivate seaweeds on your farm?Why cultivate seaweeds on your farm?
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEMEFFLUENT CHANNEL INLETEFFLUENT CHANNEL INLET
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
INLETINLET
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEMSLUICE GATESLUICE GATE
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEMINLETINLET
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
PADDLE AND DRIVEPADDLE AND DRIVE
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
POND PROFILE VIEWPOND PROFILE VIEW
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
PADDLE WHEELPADDLE WHEEL
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEMMIDDLE DIVIDER WALLMIDDLE DIVIDER WALL
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
OUTLET BARRIEROUTLET BARRIER
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
OUTLETOUTLET
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
EFFLUENT AND HARVESTING CHANNELEFFLUENT AND HARVESTING CHANNEL
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
HARVESTING AREAHARVESTING AREA
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
PARENT STOCKPARENT STOCK
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
PADDLE POND DESIGNPADDLE POND DESIGN
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
COST OF A SINGLE PONDCOST OF A SINGLE POND Concrete casted 40000
Sand floor (compacted) 1400
HDPE white liner 750 micron 2 X 6 X 38 m 8800
Coverstrips 8 mm X 40 mm X 120 m HDPE 1500
S/S screws 40 mm X 4.2 mm X 500/pond 225
Elec motor and gearbox 3 KW & chain & sprockets 10400
Paddle and bearings 9000
Cover for elec motor (fibreglass) 450
Channel @ R650/m X 18 11700
Sluice gate for incoming water 350
Civils to level out & compact platform @ R25/m2 6840
Elec cable for supply and D. B. 3500
TOTAL 94165
Why is a controlled feed source important?
• Abalone are herbivores
• They obtain all of their protein requirement from their diet
• Their FCR is affected by phenols (an anti-grazer deterrent produced by most seaweeds)
• Kelps can contain very high proportions of phenols
• Abalone obtain all their calcium requirement through their gills, but no phosphate
• The phosphate requirement has to be met by the diet
• Abalone are sold by weight and there can be up to a 30% water loss during transport
RESULTS
Important because:
• Increases protein from wild harvest (3.7- 24 % wild to 49.8 % cultured)
• Abalone receive more protein
• Faster growth rates
How do you increase tissue nutrients?
• Faster flow rates (12 – 20 volume exchanges)
• Grown in turbot/fish or abalone effluent
• Add Fertilizer and Kelpak®
Tissue Nitrogen
RESULTSTissue Nitrogen vs. Thallus Colour
Tissue nitrogen vs. thallus colour
RESULTSTissue Nitrogen vs. Tissue Phosphorus
Tissue N vs. Tissue P
0
10
20
30
40
50
Time
Rat
io o
f N:P
w ild stock turbot abalone
Small sea Medium sea
A S O N D J F M A M J J A
West Coast
Benefits of a closed system
• Increase in temperature above ambient seawater equates to an increase in growth rates
• Decrease in pumping costs
• Additional safety in times of red tide and oil spills
RESULTS
Ulva can take up 90 % of ammonium in abalone effluent at 12 volume exchanges per day
• DO values don’t go below 9 mg.l-1 at night
• Using stocking density of 3 kg.wwt.m-2 gives best uptake rates but is system specific
• Toxic ammonia never reaches levels harmful to abalone at above stocking density
RECIRCULATION
RESULTS
Temperature in a recirculation system
Temperature
7.0
12.0
17.0
22.0
27.0
incoming sea seaw eed3
15 16 20 00 04 08 12 16 20 00 04 08 12 16
RESULTS
Temperature in a recirculation system
Temperature
7.0
12.0
17.0
22.0
27.0
incoming sea Recirc seaw eed3
15 16 20 00 04 08 12 16 20 00 04 08 12 16
RESULTS
ammonium levels in recirculated tanks range between
0.003 - 0.005 ug N.L-1
ammonium levels in abalone flow through tanks
= 0.01 ug N.L-1
Ammonium levels
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEMSEAWEED MANEGMENTSEAWEED MANEGMENT
PARENT STOCKPARENT STOCK
• Separate management strategy to pondsSeparate management strategy to ponds
• Hand removal of epiphytesHand removal of epiphytes
• Shading with 20 % shade clothShading with 20 % shade cloth
• Fertilize once weeklyFertilize once weekly
• KELPAKKELPAK®® and fresh water treatment prior to and fresh water treatment prior to out stockingout stocking
• Initial stocking density 1 kg.mInitial stocking density 1 kg.m22 = 400 kg per = 400 kg per pondpond
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEMPADDLE POND PRODUCTIONPADDLE POND PRODUCTION
FEED STOCKFEED STOCK
• Each pond initially stocked with epiphyte free Each pond initially stocked with epiphyte free materialmaterial
• Initial stocking density 1 kg.mInitial stocking density 1 kg.m22
• Harvest stocking density 5 – 7 kg.mHarvest stocking density 5 – 7 kg.m22
• Fertilize once weekly: pulse fertilization Fertilize once weekly: pulse fertilization
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
BENEFITSBENEFITS
• 1.3 tons of nutrient rich seaweed every second 1.3 tons of nutrient rich seaweed every second working dayworking day
• Easy to harvestEasy to harvest
• Potential for recirculationPotential for recirculation
• Production of controlled food sourceProduction of controlled food source
• Better quality diet for abalone Better quality diet for abalone
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
PRODUCTION FIGURESPRODUCTION FIGURES
PRODUCTION PRODUCTION = = 1.3 tons1.3 tons of nutrient rich seaweed every second of nutrient rich seaweed every second working day from paddle pondsworking day from paddle ponds
AT PRESENTAT PRESENT = = 12 platforms12 platforms
Each requiring an average of Each requiring an average of 1.8 tons1.8 tons of kelp per week of kelp per week
A four week 50 % rotation diet would require 900 kg cultivated seaweed A four week 50 % rotation diet would require 900 kg cultivated seaweed in a month per platform.in a month per platform.
Therefore total platform cultivated seaweed demand = Therefore total platform cultivated seaweed demand = 10.8 Tons10.8 Tons
16 ponds16 ponds are capable of producing are capable of producing 13.2 tons13.2 tons of seaweed in a month of seaweed in a month
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
PRODUCTION FIGURESPRODUCTION FIGURES This means that we have an excess of 2.4 tons which could feed This means that we have an excess of 2.4 tons which could feed another 2 platforms.another 2 platforms.
10.8 tons of kelp costs R115 000 now10.8 tons of kelp costs R115 000 now
Thus the ponds have a direct saving of R115 000.Thus the ponds have a direct saving of R115 000.
There is also the benefit of faster growth rates and increased There is also the benefit of faster growth rates and increased production with the same running costs due to the abalone being fed a production with the same running costs due to the abalone being fed a protein rich dietprotein rich diet
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEMECONOMICSECONOMICS
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM ECONOMICSECONOMICS
Abalone growth curvesAbalone growth curves
0
50
100
150
200
250
300
0 1 2 3 4 5 6Years
We
igh
t (g
)
von-B linear wild exponential @49 exponential@68
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
31.2 % increase in weight using rotation diet vs. kelp only diet over 9 months
Cost: $30 per kg X R 8 = R 240
10 (100g) abalone in 1 kg
cost per abalone = R 24
less profit and freight
= R 15 per abalone
ECONOMICSECONOMICS
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
Increase in SGR: Normal Growth to 100g = 5 years
accelerated growth = 3.3 – 3.6 years
@ R 15 per abalone
New cost : R 12.40 – R 13.50 per abalone
Savings: 17 – 28 %
R 1.50 - R 2.60 per abalone
ECONOMICS
SEAWEED PADDLE POND SYSTEMSEAWEED PADDLE POND SYSTEM
I & J farm (120 tons @ 100 g per abalone)
= 1 2000 000 100g abalone
X R 1.50 or R 2.60
EQUALS
Savings:
R 1.8 – R 3.12 million
ECONOMICS
Thank you for listening
SEAWEED PADDLE POND SEAWEED PADDLE POND SYSTEMSYSTEM