seaweed farming

File:NOAA video about kelp farming.ogg explains his farming methods, including the symbiotic relationship kelp has with other seafood he grows.]]

The earliest seaweed farming guides in the Philippines recommended the cultivation of Laminaria seaweed and reef flats at approximately one meter's depth at low tide. They also recommended cutting off seagrasses and removing sea urchins before farm construction. Seedlings are tied to monofilament lines and strung between mangrove stakes in the substrate. This off-bottom method remains a primary method.{{sfn|Crawford| 2002| p=2}}

Long-line cultivation methods can be used in water approximately {{Convert|7|m|sp=us}} in depth. Floating cultivation lines are anchored to the bottom and are widely used in North Sulawesi, Indonesia.{{sfn|Pollnac|1997a| p= 67}}{{sfn|Pollnac| 1997b| p= 79}} Species cultured by long-line include those of the genera Saccharina, Undaria, Eucheuma, Kappaphycus, and Gracilaria.{{Cite book|url=https://books.google.com/books?id=GaLTpv3OrfkC&pg=PA276|title=Aquaculture: Farming Aquatic Animals and Plants|publisher=Blackwell Publishing|others=Lucas, John S., 1940-, Southgate, Paul C.|year=2012|isbn=978-1-4443-4710-4|editor-last=Lucas|editor-first=John S|edition=2nd|location=Chichester, West Sussex|pages=276|oclc=778436274|editor-last2=Southgate|editor-first2=Paul C}}

Cultivation in Asia is relatively low-technology with a high labor requirement. Attempts to introduce technology to cultivate detached plant growth in tanks on land to reduce labor have yet to attain commercial viability.{{sfn|Crawford| 2002| p=2}}

A bacterial infection called ice-ice stunts seaweed crops. In the Philippines 15 percent reduction in one species appeared in 2011 to 2013, representing 268,000 tonnes of seaweed. The spread of ice-ice disease is strongly associated with increasing seawater temperatures.{{Cite journal |title=Ice-Ice disease: An environmentally and microbiologically driven syndrome in tropical seaweed aquaculture |date=2022 |url=https://onlinelibrary.wiley.com/doi/epdf/10.1111/raq.12606 |language=en |doi=10.1111/raq.12606 |last1=Ward |first1=Georgia M. |last2=Kambey |first2=Cicilia S. B. |last3=Faisan |first3=Joseph P. |last4=Tan |first4=Pui-Ling |last5=Daumich |first5=Caroline C. |last6=Matoju |first6=Ivy |last7=Stentiford |first7=Grant D. |last8=Bass |first8=David |last9=Lim |first9=Phaik-Eem |last10=Brodie |first10=Juliet |last11=Poong |first11=Sze-Wan |journal=Reviews in Aquaculture |volume=14 |issue=1 |pages=414–439 |bibcode=2022RvAq...14..414W }}

File:Seaweed Farms in South Korea (detail) (17322757055).jpg]]

Seaweed is an extractive crop that has little need for fertilisers or water, meaning that seaweed farms typically have a smaller environmental footprint than other agriculture or fed aquaculture.{{Cite journal|last1=Hasselström|first1=Linus|last2=Visch|first2=Wouter|last3=Gröndahl|first3=Fredrik|last4=Nylund|first4=Göran M.|last5=Pavia|first5=Henrik|date=2018|title=The impact of seaweed cultivation on ecosystem services - a case study from the west coast of Sweden|journal=Marine Pollution Bulletin|volume=133|pages=53–64|doi=10.1016/j.marpolbul.2018.05.005|pmid=30041346 |bibcode=2018MarPB.133...53H |s2cid=51715114 |issn=0025-326X|doi-access=free}}{{Cite journal|last1=Visch|first1=Wouter|last2=Kononets|first2=Mikhail|last3=Hall|first3=Per O. J.|last4=Nylund|first4=Göran M.|last5=Pavia|first5=Henrik|date=2020|title=Environmental impact of kelp (Saccharina latissima) aquaculture|journal=Marine Pollution Bulletin|volume=155|pages=110962|doi=10.1016/j.marpolbul.2020.110962|pmid=32469791 |bibcode=2020MarPB.15510962V |s2cid=219105485 |issn=0025-326X|doi-access=free}}{{Cite journal|last1=Zhang|first1=Jihong|last2=Hansen|first2=Pia Kupka|last3=Fang|first3=Jianguang|last4=Wang|first4=Wei|last5=Jiang|first5=Zengjie|date=2009|title=Assessment of the local environmental impact of intensive marine shellfish and seaweed farming—Application of the MOM system in the Sungo Bay, China

|journal=Aquaculture|volume=287|issue=3–4 |pages=304–310|doi=10.1016/j.aquaculture.2008.10.008|bibcode=2009Aquac.287..304Z |issn=0044-8486}} Many of the impacts of seaweed farms, both positive and negative, remain understudied and uncertain.

Nonetheless, many environmental problems can result from seaweed farming.{{Cite journal|last1=Campbell|first1=Iona|last2=Macleod|first2=Adrian|last3=Sahlmann|first3=Christian|last4=Neves|first4=Luiza|last5=Funderud|first5=Jon|last6=Øverland|first6=Margareth|last7=Hughes|first7=Adam D.|last8=Stanley|first8=Michele|date=2019|title=The Environmental Risks Associated With the Development of Seaweed Farming in Europe - Prioritizing Key Knowledge Gaps

|journal=Frontiers in Marine Science|volume=6|page=107 |doi=10.3389/fmars.2019.00107|issn=2296-7745|doi-access=free |bibcode=2019FrMaS...6..107C |hdl=11250/2631445|hdl-access=free}} For instance, seaweed farmers sometimes cut down mangroves to use as stakes. Removing mangroves negatively affects farming by reducing water quality and mangrove biodiversity. Farmers may remove eelgrass from their farming areas, damaging water quality.{{sfn|Zertruche-Gonzalez|1997|p=53}} Seaweed farms are routinely placed on top of seagrass meadows, particularly across Southeast Asia and the Western Indian Ocean, and numerous negative impacts occur. {{Cite journal |last=Jones |first=Benjamin |date=2025-02-18 |title=Risks of habitat loss from seaweed cultivation within seagrass|url=https://www.pnas.org/doi/10.1073/pnas.2426971122 |doi=10.1073/pnas.2426971122 |journal=PNAS|doi-access=free |pmc=11874594 }}

Seaweed farming can pose a biosecurity risk, as farming activities have the potential to introduce or facilitate invasive species.{{Cite journal|last1=Corrigan|first1=Sophie|last2=Brown|first2=Andrew R.|last3=Ashton|first3=Ian G. C.|last4=Smale|first4=Dan|last5=Tyler|first5=Charles R.|date=2022|title=Quantifying habitat provisioning at macroalgal cultivation sites

|journal=Reviews in Aquaculture|volume=14 |issue=3 |pages=1671–1694 |doi=10.1111/raq.12669|bibcode=2022RvAq...14.1671C |hdl=10871/128931 |s2cid=247242097 |issn=1753-5131|url=https://plymsea.ac.uk/id/eprint/9643/1/Reviews%20in%20Aquaculture%20-%202022%20-%20Corrigan%20-%20Quantifying%20habitat%20provisioning%20at%20macroalgal%20cultivation%20sites.pdf }}{{Cite journal|last1=Forbes|first1=Hunter|last2=Shelamoff|first2=Victor|last3=Visch|first3=Wouter|last4=Layton|first4=Cayne|date=2022|title=Farms and forests: evaluating the biodiversity benefits of kelp aquaculture

|journal=Journal of Applied Phycology|volume=34 |issue=6 |pages=3059–3067 |doi=10.1007/s10811-022-02822-y|s2cid=252024699 |issn=1573-5176|doi-access=free|bibcode=2022JAPco..34.3059F }} For this reason, regions such as the UK, Maine and British Columbia only allow native varieties.{{Cite web|last=Held|first=Lisa|date=2021-07-20|title=Kelp at the Crossroads: Should Seaweed Farming Be Better Regulated?|url=https://civileats.com/2021/07/20/kelp-at-the-crossroads-should-seaweed-farming-be-better-regulated/|access-date=2021-08-11|website=Civil Eats|language=en}}

Farms may also have positive environmental effects. They may support welcome ecosystem services such as nutrient cycling, carbon uptake, and habitat provision.{{Cite web |date=2024-02-28 |title=Seaweed Aquaculture |url=https://www.fisheries.noaa.gov/national/aquaculture/seaweed-aquaculture |access-date=2025-01-26 |website=NOAA Fisheries |language=en}}

Evidence suggests that seaweed farming can have positive impacts which include supplementing human diets, feeding livestock, creating biofuels, slowing climate change and providing crucial habitat for a marine life, but must scale sustainably in order to have these effects.{{Cite web |last=Lapointe |first=Ellyn |date=2023-05-18 |title=Global seaweed farming could be a boon, but only if it scales sustainably |url=https://scienceline.org/2023/05/global-seaweed-farming-could-be-a-boon-but-only-if-it-scales-sustainably/ |access-date=2024-01-11 |website=Scienceline |language=en-US}} One way for seaweed farming to scale at terrestrial farming levels is with the use of ROVs, which can install low-cost helical anchors that can extend seaweed farming into unprotected waters.{{Cite web |title=Ocean Upwelling |url=https://www.oceanupwelling.com/ |access-date=2024-01-11 |website=Ocean Upwelling |language=en-US}}

Seaweed can be used to capture, absorb, and incorporate excess nutrients into living tissue, aka nutrient bioextraction/bioharvesting, is the practice of farming and harvesting shellfish and seaweed to remove nitrogen and other nutrients from natural water bodies.{{cite web|last=NOAA|title=Nutrient Bioextraction Overview|url=https://longislandsoundstudy.net/issues-actions/water-quality/nutrient-bioextraction-overview/?doing_wp_cron=1369944259.2313320636749267578125|publisher=Long Island Sound Study}}

Similarly, seaweed farms may offer habitat that enhances biodiversity. Seaweed farms have been proposed to protect coral reefs{{sfn|Zertruche-Gonzalez|1997|p=54}} by increasing diversity, providing habitat for local marine species. Farming may increase the production of herbivorous fish and shellfish. Pollinac reported an increase in Siginid population after the start of farming of Eucheuma seaweed in villages in North Sulawesi.{{sfn|Pollnac|1997b|p= 79}}

File:PEI harvesting seaweed.JPG (Canada)]]

In Japan the annual production of nori amounts to US$2 billion and is one of the world's most valuable aquaculture crops. The demand for seaweed production provides plentiful work opportunities.

A study conducted by the Philippines reported that plots of approximately one hectare could produce net income from Eucheuma farming was 5 to 6 times the average wage of an agriculture worker. The study also reported an increase in seaweed exports from 675 metric tons (MT) in 1967 to 13,191 MT in 1980, and 28,000 MT by 1988.{{sfn|Trono|1990|p=4}}

About 0.7 million tonnes of carbon are removed from the sea each year by commercially harvested seaweeds.{{Cite news |last1=Israel |first1=Alvaro |last2=Einav |first2=Rachel |last3=Seckbach |first3=Joseph |date=18 June 2010 |title=Seaweeds and their role in globally changing environments |publisher=Springer |language=en |url=https://books.google.com/books?id=rxe7jPwW65EC&q=nearly+0.7+million+tonnes+of+carbon+are+removed+from+the+sea+each+year+within+commercially+harvested+seaweeds&pg=PA365 |access-date=1 December 2018 |isbn=9789048185696}} In Indonesia, seaweed farms account for 40 percent of the national fisheries output and employ about one million people.

The Safe Seaweed Coalition is a research and industry group that promotes seaweed cultivation.

Seaweed farming has had widespread socio-economic impacts in Tanzania, has become a very important source of resources for women, and is the third biggest contributor of foreign currency to the country.{{Cite web |title=Evolution of Seaweed Farming in Tanzania: Achievements and Challenges Associated with Climate Change {{!}} The Ocean Policy Research Institute-OceanNewsletter |url=https://www.spf.org/en/opri/newsletter/379_1.html |access-date=2020-05-06 |website=THE SASAKAWA PEACE FOUNDATION}} 90% of the farmers are women, and much of it is used by the skincare and cosmetics industry.{{Cite news |title=Seaweed farming in Zanzibar |language=en |work=BBC News |url=https://www.bbc.com/news/av/business-50491754/seaweed-farming-in-zanzibar |access-date=2020-05-06}}

In 1982 Adelaida K. Semesi began a programme of research into seaweed cultivation in Zanzibar and its application resulted in greater investment in the industry.{{Cite book |last1=Oliveira |first1=E. C. |url=https://aquadocs.org/handle/1834/795 |title=Marine Plants of Tanzania. A field guide to the seaweeds and seagrasses of Tanzania. |last2=Österlund |first2=K. |last3=Mtolera |first3=M. S. P. |date=2003 |publisher=Sida/Department for Research Cooperation, SAREC |pages=Dedication |language=en}}

File:WomenWorking_Seaweed_Zanzibar_1.jpg|Zanzibar's seaweed growers face a changing climate. Here, a farmer tends to her farm in Paje, on the southeast coast of the island.

File:WomenWorking_SeaweedZanzibar_2.jpg|Mwanaisha Makame and Mashavu Rum, who have been farming seaweed on Zanzibar island for 20 years, wade through the low tide to their farm.

File:WomenWorking_SeaweedZanzibar_3.jpg|The seaweed grows underwater for 45 days. When it reaches one kilogram it is picked and dried, then packed in bags to be exported to countries like China, Korea, and Vietnam. There, it is used in medicines and shampoos.

File:WomenWorking_SeaweedZanzibar_4.jpg|The farmers have a lot of problems due to climate change. Two decades ago, 450 seaweed farmers roamed Paje. Now, only about 150 farmers remain.

File:WomenWorking_SeaweedZanzibar_5.jpg|Mwanaisha holds up a healthy clump of seaweed. Then she holds up seaweed the farmers will not be able to use. A hard white substance grows on it—ice-ice disease, caused by higher ocean temperatures and intense sunlight.

File:WomenWorking_SeaweedZanzibar_6.jpg|The seaweed farmers learned how to make soap from their seaweed at the Zanzibar Seaweed Center, a business that started as an NGO in 2009. At their homes, they mix water, ground seaweed powder, coconut oil, caustic soda, and essential oils in a large plastic tub.

File:WomenWorking_SeaweedZanzibar_7.jpg|Later in the week, the seaweed farmers will sell their finished soaps in Zanzibar town or to regular local customers. As seaweed levels decline, they have found a way to increase the value of their work.

File:WomenWorking_SeaweedZanzibar_8.jpg|The finished product—a bar of seaweed soap

Farmed seaweed is used in industrial products, as food, as an ingredient in animal feed, and as source material for biofuels.{{Cite web|date=2020-11-14|title=A deep dive into Zero Hunger: the seaweed revolution|url=https://news.un.org/en/story/2020/11/1077212|access-date=2021-11-24|website=UN News|language=en}}

Seaweeds are used to produce chemicals that can be used for various industrial, pharmaceutical, or food products. Two major derivative products are carrageenan and agar. Bioactive ingredients can be used for industries such as pharmaceuticals,{{Citation|last1=Siahaan|first1=Evi Amelia|title=Seaweeds: Valuable Ingredients for the Pharmaceutical Industries|date=2018|work=Grand Challenges in Marine Biotechnology|pages=49–95|editor-last=Rampelotto|editor-first=Pabulo H.|series=Grand Challenges in Biology and Biotechnology|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-69075-9_2|isbn=978-3-319-69075-9|last2=Pangestuti|first2=Ratih|last3=Kim|first3=Se-Kwon|editor2-last=Trincone|editor2-first=Antonio}} industrial food,{{Cite web|title=Seaweed.ie :: Seaweed e-numbers|url=https://www.seaweed.ie/additives/e-number.php|website=www.seaweed.ie|access-date=2020-05-07}} and cosmetics.{{Citation|last1=Couteau|first1=C.|title=Chapter 14 - Seaweed Application in Cosmetics|date=2016-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780128027721000142|work=Seaweed in Health and Disease Prevention|pages=423–441|editor-last=Fleurence|editor-first=Joël|publisher=Academic Press|language=en|isbn=978-0-12-802772-1|access-date=2020-05-07|last2=Coiffard|first2=L.|editor2-last=Levine|editor2-first=Ira}}

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Seaweed cultivation in the open ocean can act as a form of carbon sequestration to mitigate climate change.{{Cite web |last=Temple |first=James |date=2021-09-19 |title=Companies hoping to grow carbon-sucking kelp may be rushing ahead of the science |url=https://www.technologyreview.com/2021/09/19/1035889/kelp-carbon-removal-seaweed-sinking-climate-change/ |access-date=2021-11-25 |website=MIT Technology Review |language=en}} Studies have reported that nearshore seaweed forests constitute a source of blue carbon, as seaweed detritus is carried into the middle and deep ocean thereby sequestering carbon.{{Cite journal |last1=Queirós |first1=Ana Moura |last2=Stephens |first2=Nicholas |last3=Widdicombe |first3=Stephen |last4=Tait |first4=Karen |last5=McCoy |first5=Sophie J. |last6=Ingels |first6=Jeroen |last7=Rühl |first7=Saskia |last8=Airs |first8=Ruth |last9=Beesley |first9=Amanda |last10=Carnovale |first10=Giorgia |last11=Cazenave |first11=Pierre |date=2019 |title=Connected macroalgal-sediment systems: blue carbon and food webs in the deep coastal ocean |journal=Ecological Monographs |language=en |volume=89 |issue=3 |pages=e01366 |doi=10.1002/ecm.1366 |issn=1557-7015 |doi-access=free|bibcode=2019EcoM...89E1366Q }}{{Cite journal |last1=Wernberg |first1=Thomas |last2=Filbee-Dexter |first2=Karen |date=December 2018 |title=Grazers extend blue carbon transfer by slowing sinking speeds of kelp detritus |journal=Scientific Reports |language=en |volume=8 |issue=1 |pages=17180 |bibcode=2018NatSR...817180W |doi=10.1038/s41598-018-34721-z |issn=2045-2322 |pmc=6249265 |pmid=30464260}}{{Cite journal |last1=Krause-Jensen |first1=Dorte |last2=Lavery |first2=Paul |last3=Serrano |first3=Oscar |last4=Marbà |first4=Núria |last5=Masque |first5=Pere |last6=Duarte |first6=Carlos M. |date=2018-06-30 |title=Sequestration of macroalgal carbon: the elephant in the Blue Carbon room |journal=Biology Letters |volume=14 |issue=6 |pages=20180236 |doi=10.1098/rsbl.2018.0236 |pmc=6030603 |pmid=29925564}} Macrocystis pyrifera (also known as giant kelp) sequesters carbon faster than any other species. It can reach {{Convert|60|m|abbr=on}} in length and grow as rapidly as {{Convert|50|cm|abbr=on}} a day.{{Cite book |last=Schiel, David R. |title=The biology and ecology of giant kelp forests |date=May 2015 |others=Foster, Michael S. |isbn=978-0-520-96109-8 |location=Oakland, California |oclc=906925033}} According to one study, covering 9% of the world's oceans with kelp forests could produce "sufficient biomethane to replace all of today's needs in fossil fuel energy, while removing 53 billion tons of CO₂ per year from the atmosphere, restoring pre-industrial levels".{{Cite journal |last1=N‘Yeurt |first1=Antoine de Ramon |last2=Chynoweth |first2=David P. |last3=Capron |first3=Mark E. |last4=Stewart |first4=Jim R. |last5=Hasan |first5=Mohammed A. |date=2012-11-01 |title=Negative carbon via Ocean Afforestation |url=http://www.sciencedirect.com/science/article/pii/S0957582012001206 |journal=Process Safety and Environmental Protection |series=Special Issue: Negative emissions technology |language=en |volume=90 |issue=6 |pages=467–474 |doi=10.1016/j.psep.2012.10.008 |bibcode=2012PSEP...90..467N |s2cid=98479418 |issn=0957-5820}}{{Cite web |last=Buck |first=Holly Jean |date=April 23, 2019 |title=The desperate race to cool the ocean before it's too late |url=https://www.technologyreview.com/s/613327/the-desperate-race-to-cool-the-ocean-before-its-too-late/ |access-date=2019-04-28 |website=MIT Technology Review |language=en-US}}

Seaweed farming may be an initial step towards adapting to and mitigating climate change. These include shoreline protection through the dissipation of wave energy, which is especially important to mangrove shorelines. Carbon dioxide intake would raise pH locally, benefitting calcifiers (e.g. crustaceans) or in reducing coral bleaching. Finally, seaweed farming could provide oxygen input to coastal waters, thus countering ocean deoxygenation driven by rising ocean temperature.{{Cite web |last=Carr |first=Gabriela |date=2021-03-15 |title=Regenerative Ocean Farming: How Can Polycultures Help Our Coasts? |url=https://smea.uw.edu/currents/regenerative-ocean-farming-how-can-polycultures-help-our-coasts/ |access-date=2021-10-29 |website=School of Marine and Environmental Affairs |language=en-US}}

Tim Flannery claimed that growing seaweeds in the open ocean, facilitated by artificial upwelling and substrate, can enable carbon sequestration if seaweeds are sunk to depths greater than one kilometer.{{Cite book |last=Flannery |first=Tim |title=Sunlight and Seaweed: An Argument for How to Feed, Power and Clean Up the World |publisher=The Text Publishing Company |year=2017 |isbn=9781925498684 |location=Melbourne, Victoria}}{{Cite web |last=Flannery |first=Tim |date=July 2019 |title=Can Seaweed Help Curb Global Warming |url=https://www.ted.com/talks/tim_flannery_can_seaweed_help_curb_global_warming?language=en |website=TED}}{{Cite web |date=August 2017 |title=Can Seaweed Save the World |url=https://www.abc.net.au/catalyst/can-seaweed-save-the-world/11017106#:~:text=Professor%20Tim%20Flannery%20investigates%20how,and%20even%20combating%20climate%20change. |website=ABC Australia}}

Seaweed contributes approximately 16–18.7% of the total marine-vegetation sink. In 2010 there were 19.2 × $10^6$ tons of aquatic plants worldwide, 6.8 × $10^6$ tons for brown seaweeds; 9.0 × $10^6$ tons for red seaweeds; 0.2 × $10^6$ tons of green seaweeds; and 3.2 × $10^6$ tons of miscellaneous aquatic plants. Seaweed is largely transported from coastal areas to the open and deep ocean, acting as a permanent storage of carbon biomass within marine sediments.{{Cite journal |last1=Ortega |first1=Alejandra |last2=Geraldi |first2=N.R. |last3=Alam |first3=I. |last4=Kamau |first4=A.A. |last5=Acinas |first5=S. |last6=Logares |first6=R. |last7=Gasol |first7=J. |last8=Massana |first8=R. |last9=Krause-Jensen |first9=D. |last10=Duarte |first10=C. |year=2019 |title=Important contribution of macroalgae to oceanic carbon sequestration |url=https://www.nature.com/articles/s41561%20019%200421%208 |journal=Nature Geoscience |language=en |volume=12 |issue=9 |pages=748–754 |bibcode=2019NatGe..12..748O |doi=10.1038/s41561-019-0421-8 |hdl-access=free |hdl=10754/656768 |s2cid=199448971}}

Ocean afforestation is a proposal for farming seaweed for carbon removal.{{Cite web |last=Woody |first=Todd |date=2019-08-29 |title=Forests of seaweed can help climate change—without risk of fire |url=https://www.nationalgeographic.com/environment/article/forests-of-seaweed-can-help-climate-change-without-fire |archive-url=https://web.archive.org/web/20210222104353/https://www.nationalgeographic.com/environment/article/forests-of-seaweed-can-help-climate-change-without-fire |url-status=dead |archive-date=February 22, 2021 |access-date=2021-11-15 |website=National Geographic |language=en}} After harvesting seaweed is decomposed into biogas (60% methane and 40% carbon dioxide) in an anaerobic digester. The methane can be used as a biofuel, while the carbon dioxide can be stored to keep it from the atmosphere.

Similarly, the NGO Climate Foundation and permaculture experts claimed that offshore seaweed ecosystems can be cultivated according to permaculture principles, constituting marine permaculture.{{Cite book |last=Hawken |first=Paul |title=Drawdown: the Most Comprehensive Plan Ever Proposed to Reverse Global Warming |publisher=Penguin Random House |year=2017 |isbn=9780143130444 |location=New York, New York |pages=178–180}}{{cite AV media |title=2040 |date=May 23, 2019 |medium=Motion picture |publisher=Good Things Productions |location=Australia |people=Gameau, Damon (Director)}}{{Cite web |last=Von Herzen |first=Brian |date=June 2019 |title=Reverse Climate Change with Marine Permaculture Strategies for Ocean Regeneration |url=https://www.youtube.com/watch?v=9Ch65gqD1g4 |url-status=live |archive-url=https://ghostarchive.org/varchive/youtube/20211215/9Ch65gqD1g4 |archive-date=2021-12-15 |website=Youtube}}{{cbignore}}{{Cite web |last=Powers |first=Matt |title=Marine Permaculture with Brian Von Herzen Episode 113 A Regenerative Future |url=https://www.youtube.com/watch?v=ZJLHJJNBsVI |url-status=live |archive-url=https://ghostarchive.org/varchive/youtube/20211215/ZJLHJJNBsVI |archive-date=2021-12-15 |website=Youtube|date=10 July 2019 }}{{cbignore}}{{Cite web |date=December 2019 |title=Marine Permaculture with Dr Brian von Herzen & Morag Gamble |url=https://www.youtube.com/watch?v=y8RojQZbsB8 |url-status=live |archive-url=https://ghostarchive.org/varchive/youtube/20211215/y8RojQZbsB8 |archive-date=2021-12-15 |website=Youtube}}{{cbignore}} The concept envisions using artificial upwelling and floating, submerged platforms as substrate to replicate natural seaweed ecosystems that provide habitat and the basis of a trophic pyramid for marine life.{{Cite web |title=Climate Foundation: Marine Permaculture |url=https://www.climatefoundation.org/what-is-marine-permaculture.html |access-date=2020-07-05 |website=Climate Foundation |language=en}} Seaweeds and fish can be sustainably harvested. As of 2020, successful trials had taken place in Hawaii, the Philippines, Puerto Rico and Tasmania.{{Cite web |title=Climate Foundation: Marine Permaculture |url=https://www.climatefoundation.org/marine-permaculture.html |access-date=2020-07-05 |website=Climate Foundation |language=en}}{{Cite web |title=Assessing the Potential for Restoration and Permaculture of Tasmania's Giant Kelp Forests - Institute for Marine and Antarctic Studies |url=https://www.imas.utas.edu.au/research/ecology-and-biodiversity/projects/projects/assessing-the-potential-for-restoration-and-permaculture-of-tasmanias-giant-kelp-forests |access-date=2020-07-05 |website=Institute for Marine and Antarctic Studies - University of Tasmania, Australia |language=en-AU}} The idea featured as a solution covered by the documentary 2040 and in the book Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming.

File:FMIB 53548 On cueillie l'Asaksanori dans la plantation (Sudate) de Daisikaware dans la hail de la riviere Tamagawa.jpeg estuary used for growing Porphyra algae in Japan, c. 1921]]

Human use of seaweed is known from the Neolithic period. Cultivation of gim (laver) in Korea is reported in books from the 15th century.{{Cite book |last=Yi |first=Haeng |url=https://www.krpia.co.kr/knowledge/itkc/detail?artClass=MK&artId=kc_mk_g012 |title=Sinjeung Dongguk Yeoji Seungnam |year=1530 |location=Joseon Korea |language=lzh |script-title=ko:신증동국여지승람(新增東國輿地勝覽) |trans-title=Revised and Augmented Survey of the Geography of Korea |orig-year=1481}}{{Cite book |last1=Ha |first1=Yeon |title=Gyeongsang-do Jiriji |last2=Geum |first2=Yu |last3=Gim |first3=Bin |year=1425 |location=Joseon Korea |language=ko |script-title=ko:경상도지리지(慶尙道地理志) |trans-title=Geography of Gyeongsang Province}} Seaweed farming began in Japan as early as 1670 in Tokyo Bay.{{sfn|Borgese|1980|p=112}} In autumn of each year, farmers would throw bamboo branches into shallow, muddy water, where the spores of the seaweed would collect. A few weeks later these branches would be moved to a river estuary. Nutrients from the river helped the seaweed to grow.{{sfn|Borgese|1980|p=112}}File:Eucheuma farming, Philippines (5211726822).jpg farming in the Philippines]]

In the 1940s, the Japanese improved this method by placing nets of synthetic material tied to bamboo poles. This effectively doubled production.{{sfn|Borgese|1980|p=112}} A cheaper variant of this method is called the hibi method—ropes stretched between bamboo poles. In the early 1970s, demand for seaweed and seaweed products outstripped supply, and cultivation was viewed as the best means to increase production.{{sfn|Naylor|1976|p=73}}

In the tropics, commercial cultivation of Caulerpa lentillifera (sea grapes) was pioneered in the 1950s in Cebu, Philippines, after accidental introduction of C. lentillifera to fish ponds on the island of Mactan.{{cite book |last1=Trono |first1=Gavino C. Jr. |url=https://www.fao.org/3/ac417e/AC417E00.htm |title=Manual on Seaweed Culture |date=December 1988 |publisher=ASEAN/UNDP/FAO Regional Small-Scale Coastal Fisheries Development Project}}{{cite web |last1=Dela Cruz |first1=Rita T. |title=Lato: Nutritious Grapes from the Sea |url=https://www.bar.gov.ph/index.php/digest-home/digest-archives/769-2015-4th-quarter/5953-lato-nutritious-grapes-from-the-sea |access-date=26 October 2020 |website=BAR Digest |publisher=Bureau of Agricultural Research, Republic of the Philippines}} This was further developed by local research, particularly through the efforts of Gavino Trono, since recognized as a National Scientist of the Philippines. Local research and experimental cultures led to the development of the first commercial farming methods for other warm-water algae (since cold-water red and brown edible algae favored in East Asia do not grow in the tropics), including the first successful commercial cultivation of carrageenan-producing algae. These include Eucheuma spp., Kappaphycus alvarezii, Gracilaria spp., and Halymenia durvillei.{{cite web |title=Academician Gavino C. Trono, Jr. is National Scientist |url=http://www.nast.ph/index.php?option=com_content&view=article&id=500%3Aacademician-gavino-trono&catid=1%3Anews |url-status=dead |archive-url=https://web.archive.org/web/20140826122139/http://www.nast.ph/index.php?option=com_content&view=article&id=500%3Aacademician-gavino-trono&catid=1%3Anews |archive-date=2014-08-26 |access-date=8 February 2021 |website=National Academy of Science and Technology |publisher=Department of Science and Technology, Republic of the Philippines}}{{cite news |last1=Pazzibugan |first1=Dona Z. |date=7 September 2014 |title=Marine scientist pursues 47-yr study, uses of seaweeds |newspaper=Philippine Daily Inquirer |url=https://newsinfo.inquirer.net/635863/marine-scientist-pursues-47-yr-study-uses-of-seaweeds |access-date=8 February 2021}}{{cite web |title=Eucheuma spp |url=https://www.fao.org/fishery/culturedspecies/Eucheuma_spp/en |access-date=8 February 2021 |website=Cultured Aquatic Species Information Programme |publisher=Food and Agriculture Organization of the United Nations}}{{cite journal |last1=Hurtado |first1=Anicia Q. |last2=Neish |first2=Iain C. |last3=Critchley |first3=Alan T. |date=October 2015 |title=Developments in production technology of Kappaphycus in the Philippines: more than four decades of farming |journal=Journal of Applied Phycology |volume=27 |issue=5 |pages=1945–1961 |doi=10.1007/s10811-014-0510-4 |bibcode=2015JAPco..27.1945H |s2cid=23287433}} In 1997, it was estimated that 40,000 people in the Philippines made their living through seaweed farming.{{sfn|Zertruche-Gonzalez|1997|p=54}} The Philippines was the world's largest producer of carrageenan for several decades until it was overtaken by Indonesia in 2008.{{cite news |last1=Habito |first1=Cielito F. |date=1 November 2011 |title=Sustaining seaweeds |newspaper=Philippine Daily Inquirer |url=https://opinion.inquirer.net/16365/sustaining-seaweeds |access-date=8 February 2021}}{{cite journal |last1=Bixler |first1=Harris J. |date=July 1996 |title=Recent developments in manufacturing and marketing carrageenan |journal=Hydrobiologia |volume=326-327 |issue=1 |pages=35–57 |doi=10.1007/BF00047785 |bibcode=1996HyBio.326...35B |s2cid=27265034}}{{cite news |last1=Pareño |first1=Roel |date=14 September 2011 |title=DA: Phl to regain leadership in seaweed production |work=PhilStar Global |url=https://www.philstar.com/nation/2011/09/14/726503/da-phl-regain-leadership-seaweed-production |access-date=8 February 2021}}{{cite book |url=http://seaknowledgebank.net/sites/default/files/Business%20Concept%20Community-based%20Seaweed%20Farming%20Philippines%20-%20FINAL_0.pdf |title=Impact Investment for a Business Venture for Community-Based Seaweed Farming in Northern Palawan, Philippines |date=2017 |publisher=Blue Economy Impact Investment East Asia & Partnerships in Environmental Management for the Seas of East Asia |access-date=8 February 2021}}

Seaweed farming spread beyond Japan and the Philippines to southeast Asia, Canada, Great Britain, Spain, and the United States.{{sfn|Borgese|1980|p=111}}

In the 2000s, seaweed farming has been getting increasing attention due to its potential for mitigating both climate change and other environmental issues, such as agricultural runoff.{{Cite web |last=Johnson |first=Ayana Elizabeth |last2=Maher-Johnson |first2=Louise Elizabeth |title=Soil and Seaweed: Farming Our Way to a Climate Solution |url=https://blogs.scientificamerican.com/observations/soil-and-seaweed-farming-our-way-to-a-climate-solution/ |access-date=2020-05-07 |website=Scientific American Blog Network |language=en}}{{Cite web |date=2017-07-26 |title=Vertical ocean farms that can feed us and help our seas |url=https://ideas.ted.com/vertical-ocean-farms-that-can-feed-us-and-help-our-seas/ |access-date=2020-05-07 |website=ideas.ted.com |language=en}} Seaweed farming can be mixed with other aquaculture, such as shellfish, to improve water bodies, such as in the practices developed by American non-profit GreenWave. The IPCC Special Report on the Ocean and Cryosphere in a Changing Climate recommends "further research attention" as a mitigation tactic.

In 2024 a commercial-scale seaweed farm began construction within the Hollandse Kust Zuid (HKZ) 139 turbine wind farm. The project uses 13-metre long "Eco-anchors" that cover the surface with a marine life habitat using materials such as oyster shells, wood, and cork.{{Cite web |last=Hill |first=Joshua S. |date=2024-08-26 |title=Massive offshore wind project to play host to floating seaweed farm |url=https://reneweconomy.com.au/massive-offshore-wind-project-to-play-host-to-floating-seaweed-farm/ |access-date=2024-08-27 |website=RenewEconomy |language=en-AU}}

{{wikiquote}}

• Seaweed fertilizer
• Algaculture
• Aquaculture of giant kelp
• Natural resources of island countries
• Seaweed cultivator

{{Reflist|30em}}

{{Free-content attribution

| title = In brief, The State of World Fisheries and Aquaculture, 2018

| author = FAO

| publisher = FAO

| page numbers =

| source =

| documentURL = https://www.fao.org/3/ca0191en/ca0191en.pdf

| license statement URL = https://commons.wikimedia.org/wiki/File:In_brief,_The_State_of_World_Fisheries_and_Aquaculture,_2018.pdf

| license = CC BY-SA 3.0 IGO

}}

{{refbegin|30em}}

• {{cite book |title=Cottonii and Spinosum Cultivation Handbook |last=Ask |first=E.I |year=1990 |publisher=FMC BioPolymer Corporation.Philippines }}
• {{cite book |title=Seafarm: the story of aquaculture |last=Borgese |first=Elisabeth Mann |year=1980 |publisher=Harry N. Abrams, Incorporated, New York |isbn=0-8109-1604-5 |url-access=registration |url=https://archive.org/details/seafarmstoryofaq00borg }}
• {{cite book |title=Seaweed farming :An Alternative Livelihood for Small-Scale Fishers? |last=Crawford |first=B.R |year=2002 |publisher= Proyek Pesisir Publication. University of Rhode Island, Coastal Resources Center, Narragansett, Rhode Island, USA. }}
• {{cite book |title=Production, trade and utilization of seaweeds and seaweed products |last=Naylor |first=J |year=1976 |series=FAO Fisheries Technical Paper No. 159. |publisher=Food and Agriculture Organization of the United Nations |location=Rome}}
• {{cite book |title=Rapid Assessment of Coastal Management Issues on the Coast of Minahasa. |last=Pollnac |first=R.B |year=1997a |publisher=Proyek Pesisir Technical Report No: TE-97/01-E. Coastal Resources Center, University of Rhode Island, Narragansett, Rhode Island, USA. |display-authors=etal }}
• {{cite book |title=Baseline Assessment of Socioeconomic Aspects of Resources Use in the Coastal Zone of Bentenan and Tumbak. |last=Pollnac |first=R.B |year=1997b |publisher=Proyek Pesisir Technical Report No: TE-97/01-E. Coastal Resources Center, University of Rhode Island, Narragansett, Rhode Island, USA. |display-authors=etal }}
• {{cite book |title=Seaweed resources in the developing countries of Asia: production and socioeconomic implications. |last=Trono |first=G.C |year=1990 |publisher=Aquaculture Department,Southeast Asia Fisheries Development Center. Tigbauan, Iloilo, Philippines }}
• {{cite book |title=Coral Reefs: Challenges and Opportunities for Sustainable Management |last=Zertruche-Gonzalez |first=Jose A. |year=1997 |publisher=The World Bank |isbn=0-8213-4235-5 }}

{{refend}}

{{Wikiquote}}

• {{cite web|title=Seaweed farming: an economic and sustainable opportunity for Europe|date=June 9, 2020|publisher=euronews|website=YouTube|url=https://www.youtube.com/watch?v=kmmjbGRlReA}}

{{fishing industry topics|expanded=aquaculture}}

Category:Algaculture

Category:Blue carbon

Category:Seaweeds

Category:Sustainable food system