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THE EVOLUTION OF INTEGRATED SEAWEED CULTIVATION IN TEMPERATE SOUTHERN AFRICA Robertson-Andersson Deborah 1,5 ;  J. J. Bolt...
Overview <ul><li>An  overview   on the development of seaweed aquaculture in  temperate Southern Africa. </li></ul><ul><li...
Seaweed utilization history:  South Africa & Namibia <ul><li>Southern Africa has a recent history of seaweed utilization. ...
Seaweed utilization history:  Namibia <ul><li>Seaweed cultivation first started in Radford bay, L ü deritz Namibia in the ...
Seaweed utilization history:  Namibia <ul><li>Moved to pump ashore ponds then… </li></ul><ul><li>In L üderitz Bay, rope ra...
Seaweed utilization history:  South Africa <ul><li>Seaweed cultivation on an experimental scale first started in Saldanha ...
Seaweed utilization history:  South Africa <ul><li>SGR was 5 % d –1 , and a yield of 39.6 t.d.wt.ha –1 y –1 . </li></ul><u...
Seaweed utilization history:  South Africa <ul><li>In the 1990’s abalone farming started using  Haliotis midae.  </li></ul...
Seaweed cultivation history:  Eastern Cape <ul><li>From 1992 to present, 25 Masters and Honors projects looked at land  ba...
<ul><li>In 2000 research on 2 abalone farms in the western cape looked at the use of  seaweeds as biofilters and a feed so...
Seaweed cultivation history:  Western Cape Effect of harvesting on regrowth of obligate epiphytes on kelp <ul><li>In 2000 ...
Seaweed cultivation history:  Western Cape Red tide moving towards abalone intake <ul><li>In 2000 research on 2 abalone fa...
<ul><li>The aims of this research were: </li></ul><ul><ul><li>Characterise how seaweeds perform, specifically seaweed SGR,...
DEAD RESULTS:  Myrionema strangulans  (new record & range extension) INFECTED BAD INFECTION HEALTHY
RESULTS:  Tissue Nitrogen vs. Thallus  Colour
Seaweed tank  3 KW.hr pump Gravity feed  Abalone tanks Seaweed tank  25 % Recirculation  75 % Sea water  Over flow  Pilot ...
RESULTS:  Dissolved oxygen (mg.L -1 ) 15  16  20  00  04  08  12  16  20  00  04  08  12  16
RESULTS:  Dissolved oxygen (mg.L-1) 15  16  20  00  04  08  12  16  20  00  04  08  12  16  <ul><li>Dissolved oxygen trans...
RESULTS:  Temperature ( ºC) 15  16  20  00  04  08  12  16  20  00  04  08  12  16
RESULTS:  Temperature ( ºC) 15  16  20  00  04  08  12  16  20  00  04  08  12  16  <ul><li>Temperature 4 % higher in inte...
Results:   Nutrient uptake <ul><li>Nutrient analysis showed the system to be nitrogen limited and that the system  was ver...
Other results: <ul><li>Seaweed SGR </li></ul><ul><li>Tissue nutrients </li></ul><ul><li>Abalone health </li></ul><ul><li>B...
Commercial integrated seaweed abalone system:   50 % recirculation Intake   Seaweed paddle ponds  Sump   Drum filter   Aba...
<ul><li>FEED SAVINGS: </li></ul><ul><ul><li>4 ponds produce  120 tons of feed  a year at a cost of ZAR 1 100    therefore ...
SEAWEED PADDLE POND SYSTEM:   Costs and savings  <ul><li>ZAR 360 000 to build 4 ponds </li></ul><ul><li>PUMPING SAVINGS: <...
SEAWEED PADDLE POND SYSTEM:   Costs and savings  <ul><li>ENVIRONMENTAL SAVINGS: </li></ul><ul><ul><li>The seaweeds take up...
SEAWEED PADDLE POND SYSTEM:   Costs and savings  <ul><li>ENVIRONMENTAL SAVINGS: </li></ul><ul><ul><li>49,800 Euro yr -1  o...
SEAWEED PADDLE POND SYSTEM:  Negatives <ul><li>Two farms which feed  Ulva  and  Gracilaria  exclusively  experienced that ...
Socio-economic effects from seaweed cultivation in comparison to abalone farming  and related industries in SA in 2005 2 0...
Conclusion: <ul><ul><li>Integrated seaweed cultivation has developed due to economic drivers,  mainly from the abalone cul...
THANK YOU ACKNOWLEDGEMENTS I would like to extend special thanks to the following organizations without whose help this pr...
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THE EVOLUTION OF INTEGRATED SEAWEED CULTIVATION IN TEMPERATE SOUTHERN AFRICA

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This is an evolution of an earlier talk which tries to place an economic value on an IMTA system in South Africa.

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  1. 1. THE EVOLUTION OF INTEGRATED SEAWEED CULTIVATION IN TEMPERATE SOUTHERN AFRICA Robertson-Andersson Deborah 1,5 ; J. J. Bolton 1 , M. Troell 2,3 , R. J. Anderson 4 , G. Maneveldt 5 , C. Halling 2 , A. J. Smit 6 , T. Probyn 7 & S. Peall 8 1 Botany Department, U CT 2 Department of Systems Ecology, Stockholm University 3 Beijer Institute, Stockholm, Sweden 4 Seaweed Research Unit, MCM 5 Botany Department, UWC 6 School of Biological and Conservation Sciences, UKZN 7 Aquaculture Unit, MCM 8 Hearshaw and Kinnes Laboratory, UCT
  2. 2. Overview <ul><li>An overview on the development of seaweed aquaculture in temperate Southern Africa. </li></ul><ul><li>The current drivers for integrated seaweed aquaculture. </li></ul><ul><li>An integrated abalone seaweed system. </li></ul><ul><li>Economic benefits & inter-linkages abalone farming and seaweed cultivation. </li></ul><ul><li>Socio-economic effects and multiplier effects. </li></ul>
  3. 3. Seaweed utilization history: South Africa & Namibia <ul><li>Southern Africa has a recent history of seaweed utilization. </li></ul><ul><li>Beach cast harvest started in the 1940’s. </li></ul><ul><ul><li>Driver - Shortages of algal based colloids caused by WWII. </li></ul></ul>Gelidium picking on South African east coast Kelp harvesting on South African south and west coasts <ul><li>REFS: Isacs 1942, 1953 </li></ul><ul><ul><li>Anderson et al. 1989 </li></ul></ul>
  4. 4. Seaweed utilization history: Namibia <ul><li>Seaweed cultivation first started in Radford bay, L ü deritz Namibia in the 1980’s. </li></ul><ul><li>Cultivation of Gracilaria gracilis occurred in 4 - land based, semi-inter-tidal ponds. </li></ul><ul><li>By fertilizing with urea, they obtained a 10 fold increase in production over a 90 day period. </li></ul><ul><ul><li>Driver - Commercial production of Gracilaria for agar to supplement beach cast harvests. </li></ul></ul>Pictures from Google Earth REFS: Rotmann 1987 Anderson et al. 1989, 2003
  5. 5. Seaweed utilization history: Namibia <ul><li>Moved to pump ashore ponds then… </li></ul><ul><li>In L üderitz Bay, rope raft cultivation of G. gracilis was started in the 1990’s. </li></ul><ul><li>Production was 80 t y -1 in a 4 hectare area. </li></ul><ul><ul><li>Driver - High pumping and other capital costs of pond cultivation. </li></ul></ul>G. Gracilis being threaded onto “Netlon” Rope rafts in L üderitz Bay Harvested using traditional fishing boats <ul><li>REFS: Anderson et al. 1989, 2003 </li></ul><ul><ul><li>Dawes, 1985 </li></ul></ul>
  6. 6. Seaweed utilization history: South Africa <ul><li>Seaweed cultivation on an experimental scale first started in Saldanha Bay in the 1990’s using methods adapted from Namibia with G. gracilis. </li></ul><ul><li>Cultivation was successful and there was evidence of integration, with fish factory wastes being taken up by the Gracilaria. </li></ul><ul><li>Driver - Disappearance of G. gracilis wash-ups due to natural and anthropomorphic events. </li></ul>Medium to small beach wash up 1970’s – 1980’s Little to no wash up Present day REFS: Anderson et al. 1989, 2003
  7. 7. Seaweed utilization history: South Africa <ul><li>SGR was 5 % d –1 , and a yield of 39.6 t.d.wt.ha –1 y –1 . </li></ul><ul><li>Commercial production did occur twice and experimental cultivation also occurred in St Helena bay. </li></ul><ul><ul><li>Failures due to - Thermal stratification in the bay during summer resulting in a lack of nutrients available to the seaweeds and high temperatures. </li></ul></ul><ul><ul><li>Fouling by mussels and tunicates. </li></ul></ul><ul><ul><li>H 2 S killing all seaweeds following die off of algal blooms. </li></ul></ul>Final harvest Experimental raft Monitoring of lines REFS: Anderson et al. 1989, 2003
  8. 8. Seaweed utilization history: South Africa <ul><li>In the 1990’s abalone farming started using Haliotis midae. </li></ul><ul><li>Ecklonia maxima was used as a feed source for farms on the western and South west cape coasts. </li></ul><ul><li>Driver for seaweed cultivation on land - Lack of and decrease in kelp resource to feed increasing industry. </li></ul><ul><li>Kelp concession areas being harvested at 60 – 99 % of their MSY. </li></ul>Kelp harvest vs. kelp demand as abalone feed Position of abalone farms round coast line
  9. 9. Seaweed cultivation history: Eastern Cape <ul><li>From 1992 to present, 25 Masters and Honors projects looked at land based cultivation of seaweeds. Most looked at cultivation in flow- through systems, utilizing a variety of species. </li></ul><ul><li>In 2000, 2 farms in the eastern cape built a total of 34 paddle ponds cultivating Ulva and G. gracilis based on this research. </li></ul><ul><ul><li>Driver - F ood source for abalone - high seawater temperatures cause artificial feed to ferment and bloat abalone. </li></ul></ul><ul><ul><li>Kelp doesn’t grow in the eastern cape. </li></ul></ul>Paddle ponds on a flow through system
  10. 10. <ul><li>In 2000 research on 2 abalone farms in the western cape looked at the use of seaweeds as biofilters and a feed source. Ultimately to develop an integrated abalone seaweed system. </li></ul><ul><li>Drivers – Lack of and decrease in kelp resource to feed increasing industry. </li></ul><ul><ul><li>Mixed diets are known to give better growth rates. </li></ul></ul><ul><ul><li>Potential over-harvesting and decrease in epiphyte densities on kelp after harvesting. </li></ul></ul><ul><ul><li>Limited suitable coastal areas for open ocean cultivation. </li></ul></ul><ul><ul><li>Recirculation – protection from ‘ HAB’s’ = 33 % loss in profits for 1 year. </li></ul></ul>Seaweed cultivation history: Western Cape Effect of diets on abalone growth rates Naidoo et al. 2006
  11. 11. Seaweed cultivation history: Western Cape Effect of harvesting on regrowth of obligate epiphytes on kelp <ul><li>In 2000 research on 2 abalone farms in the western cape looked at the use of seaweeds as biofilters and a feed source. Ultimately to develop an integrated abalone seaweed system. </li></ul><ul><li>Drivers – Lack of and decrease in kelp resource to feed increasing industry. </li></ul><ul><ul><li>Mixed diets are known to give better growth rates. </li></ul></ul><ul><ul><li>Potential over-harvesting and decrease in epiphyte densities on kelp after harvesting. </li></ul></ul><ul><ul><li>Limited suitable coastal areas for open ocean cultivation. </li></ul></ul><ul><ul><li>Recirculation – protection from ‘ HAB’s’ = 33 % loss in profits for 1 year. </li></ul></ul>Anderson et al. 2006
  12. 12. Seaweed cultivation history: Western Cape Red tide moving towards abalone intake <ul><li>In 2000 research on 2 abalone farms in the western cape looked at the use of seaweeds as biofilters and a feed source. Ultimately to develop an integrated abalone seaweed system. </li></ul><ul><li>Drivers – Lack of and decrease in kelp resource to feed increasing industry. </li></ul><ul><ul><li>Mixed diets are known to give better growth rates. </li></ul></ul><ul><ul><li>Potential over-harvesting and decrease in epiphyte densities on kelp after harvesting. </li></ul></ul><ul><ul><li>Limited suitable coastal areas for open ocean cultivation. </li></ul></ul><ul><ul><li>Recirculation – protection from ‘ HAB’s’ = 33 % loss in profits for 1 year. </li></ul></ul>
  13. 13. <ul><li>The aims of this research were: </li></ul><ul><ul><li>Characterise how seaweeds perform, specifically seaweed SGR, nutrient absorption capacity, nutritional quality and epiphytic assemblages. </li></ul></ul><ul><ul><li>Are the cultivated seaweeds suitable as a food source? </li></ul></ul><ul><ul><li>What was the biofilitering capacity? </li></ul></ul>Seaweed cultivation: Western Cape Small & medium tanks using abalone or fish effluent Large tanks used 5 x 1 m
  14. 14. DEAD RESULTS: Myrionema strangulans (new record & range extension) INFECTED BAD INFECTION HEALTHY
  15. 15. RESULTS: Tissue Nitrogen vs. Thallus Colour
  16. 16. Seaweed tank 3 KW.hr pump Gravity feed Abalone tanks Seaweed tank 25 % Recirculation 75 % Sea water Over flow Pilot scale integration
  17. 17. RESULTS: Dissolved oxygen (mg.L -1 ) 15 16 20 00 04 08 12 16 20 00 04 08 12 16
  18. 18. RESULTS: Dissolved oxygen (mg.L-1) 15 16 20 00 04 08 12 16 20 00 04 08 12 16 <ul><li>Dissolved oxygen transfer 33 % loss from seaweeds to abalone tanks. </li></ul>
  19. 19. RESULTS: Temperature ( ºC) 15 16 20 00 04 08 12 16 20 00 04 08 12 16
  20. 20. RESULTS: Temperature ( ºC) 15 16 20 00 04 08 12 16 20 00 04 08 12 16 <ul><li>Temperature 4 % higher in integrated tanks over 18 month period </li></ul>
  21. 21. Results: Nutrient uptake <ul><li>Nutrient analysis showed the system to be nitrogen limited and that the system was very efficient at removing nitrogen based wastes. </li></ul>0 PO 4 54.85 FAN 48.8 64.8 38.06 25 % Recirc. abalone vs. FTS abalone NO 2 NO 3 TAN % difference in nutrient uptake efficiency
  22. 22. Other results: <ul><li>Seaweed SGR </li></ul><ul><li>Tissue nutrients </li></ul><ul><li>Abalone health </li></ul><ul><li>Bacteria </li></ul><ul><li>Sediments </li></ul><ul><li>Abalone growth rates </li></ul><ul><li>Mobile macro fauna </li></ul>No significant differences Potgieter, 2005 Lindstrom, 2006 Brandt, 2006 Flodin, 2005 Hansen, 2006 Robertson-Andersson, 2003, 2007 Sankar, 2003 Bredberg, 2003
  23. 23. Commercial integrated seaweed abalone system: 50 % recirculation Intake Seaweed paddle ponds Sump Drum filter Abalone tanks Header tank Pump Seaweed harvest point Outlet
  24. 24. <ul><li>FEED SAVINGS: </li></ul><ul><ul><li>4 ponds produce 120 tons of feed a year at a cost of ZAR 1 100 therefore a direct rand value of ZAR 132 000 . </li></ul></ul><ul><ul><li>The cost of 1 ton of kelp ranges from ZAR 950 – ZAR 1 250 per ton with a FCR of between 1: 12.5 – 17 (I & J farm data) . </li></ul></ul><ul><ul><li>Cultivated Ulva has an FCR of 1: 3.6 (I & J farm data) due to its higher protein content and this means that the equivalent feed value is ZAR 478 500. </li></ul></ul>SEAWEED PADDLE POND SYSTEM: Costs and savings <ul><li>ZAR 360 000 to build 4 ponds </li></ul>
  25. 25. SEAWEED PADDLE POND SYSTEM: Costs and savings <ul><li>ZAR 360 000 to build 4 ponds </li></ul><ul><li>PUMPING SAVINGS: </li></ul><ul><ul><li>Due to the reduced head heights when pumping the total savings from having this system is an average of 20 KW.h -1 . </li></ul></ul><ul><ul><li>Electricity costs per KVA are around 16 c per unit (bulk usage for Gansbaai district, ESKOM, 2006) . </li></ul></ul><ul><ul><li>If we assume that the power correction factor for a pump is equal to 1, then 1 KVA is equal to 1 KW. </li></ul></ul><ul><ul><li>A 20 KW saving over a year would equal ZAR 20 032 . </li></ul></ul>
  26. 26. SEAWEED PADDLE POND SYSTEM: Costs and savings <ul><li>ENVIRONMENTAL SAVINGS: </li></ul><ul><ul><li>The seaweeds take up 345 tons of CO 2 y -1 </li></ul></ul><ul><ul><li>An additional 345 tons of CO 2 y -1 are saved by reducing the electricity usage </li></ul></ul><ul><ul><li>92.6 % of N is removed </li></ul></ul><ul><ul><li>A 3 % reduction in the harvesting of natural kelp beds </li></ul></ul><ul><ul><li>6 % decrease in green house gas emissions by the farm </li></ul></ul><ul><ul><li>17.8 % increase in P emissions </li></ul></ul>
  27. 27. SEAWEED PADDLE POND SYSTEM: Costs and savings <ul><li>ENVIRONMENTAL SAVINGS: </li></ul><ul><ul><li>49,800 Euro yr -1 of avoided costs for N removal; </li></ul></ul><ul><ul><li>1,400 Euro yr -1 estimated as the environmental costs for the increase in the P loads; </li></ul></ul><ul><ul><li>300 Euro yr -1 of avoided costs concerning kelp bed restoration; </li></ul></ul><ul><ul><li>4,500 Euro yr -1 of avoided costs of GHG emission offset. </li></ul></ul><ul><ul><li>The economic value = 494 200 Euro yr -1 </li></ul></ul><ul><ul><ul><li>direct benefits to the aquaculture business (estimated as the change in the aquaculture net profit, 541 thousand Euro yr -1 ) and </li></ul></ul></ul><ul><ul><ul><li>indirect environmental benefits (estimated as the value of the externalities, 53,200 Euro yr -1 ) </li></ul></ul></ul>ZAR 12.79 = € 1
  28. 28. SEAWEED PADDLE POND SYSTEM: Negatives <ul><li>Two farms which feed Ulva and Gracilaria exclusively experienced that their abalone developed an ‘ off’ taste and sulphur-like smell after the canning process. </li></ul><ul><li>Taste and smell due to evolution of DMS from DMSP. </li></ul><ul><li>Caused when abalone ingest algae high in DMSP particularly cultivated U. lactuca. </li></ul><ul><li>DMS in cans up to 44 μg.ml -1. </li></ul><ul><li>Taste threshold of DMS in water about 1000 times lower </li></ul><ul><li>However, abalone with high DMSP concentrations are preferred in the raw state. </li></ul>A A A A A B B B B B B B B C C C C C C C D D D D D D D E E E E E E Uncooked Cooked
  29. 29. Socio-economic effects from seaweed cultivation in comparison to abalone farming and related industries in SA in 2005 2 000 000 1:0.23 0 2464 150 67 CANNING Investment (ZAR) Male :female UnSkilled (%) Pay (ZAR) Tonnage (tons) Laborers 750 000 260 000 000 3 760 000 346 500 000 1:0 1:2 1:0 1:0.23 50 88 85 61 2464 1484 1813 1813 360 11019 1056 850 16 388 (600 – 1000) 12 814 ABFEED SEAWEED HARVEST SEAWEED CULTIVATION in 2006 ABALONE
  30. 30. Conclusion: <ul><ul><li>Integrated seaweed cultivation has developed due to economic drivers, mainly from the abalone cultivation industry. </li></ul></ul><ul><ul><li>The fact that U. lactuca is the largest aquaculture product in temperate Southern Africa is testament to the success of this type of aquaculture. </li></ul></ul><ul><ul><li>This development has only been possible through cooperation between research institutions and commercial enterprises. </li></ul></ul>
  31. 31. THANK YOU ACKNOWLEDGEMENTS I would like to extend special thanks to the following organizations without whose help this project would have been impossible: Swedish and South African Collaborative Program I & J Mariculture farm N R F SANCOR Prestige Student travel grant
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