Aquaculture of giant kelp

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Giant kelp

Aquaculture of giant kelp, Macrocystis pyrifera, is the cultivation of kelp for uses such as food, dietary supplements or potash.[1][2] Giant kelp contains compounds such as iodine, potassium, other minerals vitamins and carbohydrates.[3][4]


At the beginning of the 20th century California kelp beds were harvested for their potash.[1][5][6] Commercial interest increased during the 1970s and the 1980s due to the production of alginates, and also for biomass production for animal feed due to the energy crisis.[5][6][7] However commercial production for M. pyrifera never developed. With the end of the energy crisis and the decline in alginate prices, research into farming Macrocystis declined.[2]

The supply of M. pyrifera for alginate production relied heavily on restoration and management of natural beds during the early 1990s.[2][8] Other functions such as substrate stabilization were explored in California, where the “Kelp bed project” transplanted 3-6m adult specimens to increase the stability of the harbor and promote diversity.[8][3][9]

Twenty-first century

Research is investigating its use as feed for other aquaculture species such as shrimp.[8][10]

China and Chile are the largest producers of aquatic plants, each producing over 300,000 tonnes in 2007. How much of this total can be attributed to M. pyrifera is unclear.[11] Both countries culture a variety of species, in Chile 50% of the production involves Phaeophytes and the other 50% is Rhodophytes.[12] China produces a larger variety of seaweeds including chlorophytes.[13] Experiments in Chile are exploring hybrids of M. pyrifera and M. integrifolia.[14]


The most common method of cultivating M. pyrifera was developed in China in the 1950s. It is called the long line cultivation system, where the sporelings are produced in a cooled water greenhouse and then planted in the ocean attached to long lines.[15] The depth at which they are grown varies. This species alternates generations in its life cycle, cycling between a large sporophyte and a microscopic gametophyte. The sporophyte is harvested as seaweed. The mature sporophytes form the reproductive organs called sori. They are found on the underside of the leaves and produce the motile zoospores that germinate into the gametophyte.[16][17] To induce sporalation, plants are dried for up to twelve hours and placed in a seeding container filled with seawater of about 9-10 °C; salinity of 30% and a pH of 7.8-7.9.[12][15][18] Photoperiod is controlled during sporolation and growth phases. A synthetic twine of about 2 – 6mm in diameter is placed on the bottom of the same container after sporalation. The released zoospores attach to the twine and begin to germinate into male and female gametophytes.[12][15][18] Upon maturity these gametophytes release sperm and egg cells that fuse in the water column and attach themselves to the same substrate as the gametophytes (the twine).[12][15][18] These plants are reared into young sporophytes for up to 60 days.[15][18]

These strings are either wrapped around or are cut up into small pieces and attached to a larger diameter cultivation rope. The cultivation ropes vary, but extend approximately 60m with floating buoys attached.[12] The depths vary. In China, M. pyrifera is cultivated on the surface with floating buoys attached every 2-3m and the ends of the rope attached to a wooden peg anchored to the substrate. Individual ropes are usually hung at 50 cm intervals.[15] In Chile M. pyrifera is grown at a depth of 2m using buoys to keep the plants at a constant depth.[18] These are then let alone to grow until harvest.

Problems that afflict this method include management of the transition from spore to gametophyte and embryonic sporophyte which are done on a terrestrial facility with careful control of water flow, temperature, nutrients and light.[15] The Japanese use a forced cultivation method where 2 years of growth is achieved within a single growing season by controlling inputs.[15]

In China a project for offshore/deep water cultivation used various farm structures to facilitate growth, including pumping nutrients from deep water into the beds. The greatest benefit for this approach was that the algae were released from size constraints of shallow waters. Issues with operational and farm designs plagued deep water cultivation and ended further exploration.[15]


The duration of cultivation varies by region and farming intensity. This species is usually harvested after two growth seasons (2 years).[12][15] M. pyrifera that is artificially cultivated on ropes is harvested by a pulley system that is attached to boats that pull the individual lines on the vessels for cleaning.[12][15] Other countries such as the US rely primarily on naturally grown M. pyrifera, use boats to harvest the surface canopy several times per year. This is possible due to fast growth while the vegetative and reproductive parts are left undamaged.[3][19]


In the UK, legislation defines giant kelp as a nuisance. invasive specimens are mechanically removed.[20]

The demand for M. pyrifera centers on fertilizers, bioremediation and feed for abalone and sea urchins.[2][8]

Carbon sequestration

Offsetting current carbon emissions would require some 50 trillion trees. An alternative offset would be to cultivate kelp forests. Kelp can grow at 2 feet per day, 30 times faster than terrestrial plants. Planting kelp across 9% of the oceans (4.5 x the area of Australia) could provide the same offset. Additionally, the kelp would support a fish harvest of 2 megatons per year and reduce ocean acidification. Large scale open ocean forestry would require engineered substrate and added nutrients.[21]

See also


  1. ^ a b Abbott 1996.
  2. ^ a b c d Gutierrez et al. 2006.
  3. ^ a b c Bushing 2000.
  4. ^ Connor 1989, p. 58.
  5. ^ a b Neushul 1987.
  6. ^ a b Druehl et al. 1988.
  7. ^ Gerard 1987.
  8. ^ a b c d Buschmann et al. 2008.
  9. ^ Simenstad, Estes & Kenyon 1978.
  10. ^ Cruz-Suárez et al. 2009.
  11. ^ Fish and Agriculture Organization 2007.
  12. ^ a b c d e f g Buschmann et al. 2005.
  13. ^ Wu & Lin 1987.
  14. ^ Westermeier et al. 2006.
  15. ^ a b c d e f g h i j k Mariculture of Seaweeds
  16. ^ Mondragón & Mondragón 2003.
  17. ^ Prescott 1968, pp. 226-227.
  18. ^ a b c d e Westermeier, Patiño & Müller 2006.
  19. ^ Hoek et al. 1995, p. 170.
  20. ^ Schedule 9 Wildlife and Countryside Act 1981
  21. ^ Wang, Brian (2019-02-18). "The Oceans and Kelp are Critical to Solving Climate Change". Retrieved 2019-02-20.


  • Abbott, Isabella A.; Isabella, Abbott; Hollenberg, George J. (1992-08-01). Marine Algae of California. Stanford University Press. ISBN 9780804721523.
  • Abbott, Isabella A. (July 1996). "Ethnobotany of seaweeds: clues to uses of seaweeds". Hydrobiologia. 326-327 (1): 15–20. doi:10.1007/bf00047782. ISSN 0018-8158.
  • Agardh, Carl Adolph (1969). Species Algarum Rite Cognitae: Cum Synonymis, Differentiis Specificis Et Descriptionibus Succinctis. 1. Asher. pp. Part 1, pp. [i–iv], [1]–168.
  • Buschmann, Alejandro H.; Varela, Daniel A.; Hernández-González, María Carmen; Huovinen, Pirjo (2008-01-09). "Opportunities and challenges for the development of an integrated seaweed-based aquaculture activity in Chile: determining the physiological capabilities of Macrocystis and Gracilaria as biofilters". Journal of Applied Phycology. 20 (5): 571–577. doi:10.1007/s10811-007-9297-x. ISSN 0921-8971.
  • Buschmann, Alejandro; Hernández-González, María; Astudillo, C; De La Fuente, Lucia; Gutierrez, Alfonso; Aroca, Gesica (2005-09-01). "Seaweed cultivation, product development and integrated aquaculture studies in Chile". World Aquaculture. 36: 51–53.
  • Bushing, William W (2000). "MACROCYSTIS PYRIFERA, GIANT BLADDER KELP". Retrieved 2018-07-20.
  • Druehl, L. D.; Baird, R.; Lindwall, A.; Lloyd, K. E.; Pakula, S. (July 1988). "Longline cultivation of some Laminariaceae in British Columbia, Canada". Aquaculture Research. 19 (3): 253–263. doi:10.1111/j.1365-2109.1988.tb00428.x. ISSN 1355-557X.
  • Wu, Chaoyuan; Lin, Guangheng (1987). "Progress in the genetics and breeding of economic seaweeds in China". Hydrobiologia. 1: 57–61. doi:10.1007/978-94-009-4057-4_5. ISBN 9789401083010.
  • Connor, Judith (1989). Kelp Forests. Monterey Bay Aquarium Foundation. ISBN 9781878244017.
  • Cribb, A B. (1953). "Macrocystis pyrifera (L.) Ag. in Tasmanian waters" (PDF). Australian Journal of Marine and Freshwater Research. 5 (1): 1–34.
  • Cruz-Suárez, L.E.; Tapia-Salazar, M.; Nieto-López, M.G.; Guajardo-Barbosa, C.; RICQUE-MARIE, D. (August 2009). "Comparison ofUlva clathrataand the kelpsMacrocystis pyriferaandAscophyllum nodosumas ingredients in shrimp feeds". Aquaculture Nutrition. 15 (4): 421–430. doi:10.1111/j.1365-2095.2008.00607.x. ISSN 1353-5773.
  • Davis, Chuck (1991). California Reefs. Chronicle Books. ISBN 9780811800723.
  • Fish and Agriculture Organization (2007). "Fishery and Aquaculture Statistics" (PDF).
  • Gutierrez, Alfonso; Correa, Tomás; Muñoz, Verónica; Santibañez, Alejandro; Marcos, Roberto; Cáceres, Carlos; Buschmann, Alejandro H. (2006), "Farming of the giant kelp Macrocystis pyrifera in southern Chile for development of novel food products", Eighteenth International Seaweed Symposium, Springer Netherlands, pp. 33–41, doi:10.1007/978-1-4020-5670-3_5, ISBN 9781402056697
  • Hoek, Christiaan; Van den Hoeck, Hoeck; Mann, David; Jahns, H. M. (1995). Algae: An Introduction to Phycology. Cambridge University Press. ISBN 9780521316873.
  • Huisman, John Marinus (2000). Marine Plants of Australia. University of Western Australia Press. ISBN 9781876268336.
  • Kain, J M (1991-08-21). "Cultivation of attached seaweeds". In Guiry, M. D. (ed.). Seaweed Resources in Europe: Uses and Potential. Wiley. ISBN 9780471929475.
  • Hurd, Catriona L.; Harrison, Paul J.; Bischof, Kai; Lobban, Christopher S. (2014-07-17). Seaweed Ecology and Physiology. Cambridge University Press. ISBN 9780521145954.
  • "(PDF) Production of Macrocystis pyrifera (Laminariales; Phaeophyceae) in northern Chile on spore-based culture". ResearchGate. Retrieved 2019-02-20.* "Mariculture of Seaweeds" (PDF). 2010.
  • Mondragón, Jennifer; Mondragón, Jeff (2003-06-01). Seaweeds of the Pacific Coast: common marine algae from Alaska to Baja California. Sea Challengers, Incorporated. ISBN 9780930118297.
  • Neushul, M (1987). "Energy from marine biomass: The historical record". In Bird, Kimon T.; Benson, Peter H. (eds.). Seaweed cultivation for renewable resources. Elsevier. pp. 1–37. ISBN 9780444428646.
  • North, W J; Jackson, G A; Manley., S L (1986). "Macrocystis and its environment, knowns and unknowns". Aquatic Biology. 26: 9–26. Retrieved 2019-02-20 – via ScienceDirect.
  • Prescott, Gerald Webber (1968). The algae: a review. Houghton Mifflin.
  • Reed, D C. (1990) "The effects of variable settlement and early competition on patterns of kelp recruitment." Ecology 71:776-787.
  • Reed, D C, M Neushul, & A W Ebeling. (1991) "Role of settlement density on gametophyte growth and reproduction in the kelps Pterygophora californica and Macrocystis pyrifera (Phaeophyceae)." Journal of Phycology 27:361-366.
  • Simenstad, Charles A.; Estes, James A.; Kenyon, Karl W. (1978-04-28). "Aleuts, Sea Otters, and Alternate Stable-State Communities". Science. 200 (4340): 403–411. doi:10.1126/science.200.4340.403. ISSN 0036-8075. PMID 17757287.
  • Westermeier, Renato; Patiño, David; Piel, Maria Ines; Maier, Ingo; Mueller, Dieter G (February 2006). "A new approach to kelp mariculture in Chile: production of free-floating sporophyte seedlings from gametophyte cultures of Lessonia trabeculata and Macrocystis pyrifera". Aquaculture Research. 37 (2): 164–171. doi:10.1111/j.1365-2109.2005.01414.x. ISSN 1355-557X.
  • Westermeier, Renato; Patiño, David; Müller, Dieter G. (November 29, 2006). "Sexual compatibility and hybrid formation between the giant kelp species Macrocystis pyrifera and M. integrifolia (Laminariales, Phaeophyceae) in Chile". Journal of Applied Phycology. 19 (3): 215–221. doi:10.1007/s10811-006-9126-7. ISSN 0921-8971.
  • White, Leslie Paul; Plaskett, L. G. (1981). Biomass as fuel. Academic Press. ISBN 9780127469805.
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