THE EVOLUTION OF INTEGRATED SEAWEED CULTIVATION IN TEMPERATE SOUTHERN AFRICA

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This presentation was given at the International Seaweed Symposium in Kobe, Japan in 2007. It was presented in a session on IMTA. It illustrates how South Africa has advanced in seaweed cultivation.

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THE EVOLUTION OF INTEGRATED SEAWEED CULTIVATION IN TEMPERATE SOUTHERN AFRICA

  1. 1. THE EVOLUTION OF INTEGRATED SEAWEED CULTIVATION IN TEMPERATE SOUTHERN AFRICA Robertson-Andersson Deborah 1 ; 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. What phycologist’s love to do at an ISS…
  3. 3. Scenes from the symposium…
  4. 4. The Nori growing process
  5. 5. A Nori processing plant
  6. 6. THE EVOLUTION OF INTEGRATED SEAWEED CULTIVATION IN TEMPERATE SOUTHERN AFRICA Robertson-Andersson Deborah 1 ; 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
  7. 7. 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>
  8. 8. 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>
  9. 9. 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
  10. 10. 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>
  11. 11. 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
  12. 12. 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
  13. 13. 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
  14. 14. 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
  15. 15. <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
  16. 16. 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
  17. 17. 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>
  18. 18. <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
  19. 19. DEAD RESULTS: Myrionema strangulans (new record & range extension) INFECTED BAD INFECTION HEALTHY
  20. 20. RESULTS: Tissue Nitrogen vs. Thallus Colour
  21. 21. Seaweed tank 3 KW.hr pump Gravity feed Abalone tanks Seaweed tank 25 % Recirculation 75 % Sea water Over flow Pilot scale integration
  22. 22. RESULTS: Dissolved oxygen (mg.L -1 ) 15 16 20 00 04 08 12 16 20 00 04 08 12 16
  23. 23. 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>
  24. 24. RESULTS: Temperature ( ºC) 15 16 20 00 04 08 12 16 20 00 04 08 12 16
  25. 25. 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>
  26. 26. 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
  27. 27. 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
  28. 28. Commercial integrated seaweed abalone system: 50 % recirculation Intake Seaweed paddle ponds Sump Drum filter Abalone tanks Header tank Pump Seaweed harvest point Outlet
  29. 29. <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>ZAR 7.5 = $ 1
  30. 30. 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>ZAR 7.5 = $ 1
  31. 31. 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
  32. 32. 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
  33. 33. 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>
  34. 34. DOMO ARIGATO GOZAIMASS 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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