Up to 85 percent of farmed seaweed is currently used for non-staple foods and food ingredients.⁶ It is a good dietary source of micronutrients, fibre, and antioxidants.⁷ Seaweeds are a typical part of Chinese, Japanese and Korean cuisines, all of which continue to grow in popularity globally. Indonesians and Filipinos use seaweed for desserts, and a small minority use it for salads, soup, flavourings and snacks. In Malaysia, it is added to rice dishes such as nasi kerabu.

As an ingredient, seaweed is used in both edible and non-edible items. Dried seaweed is sold as hydrocolloids (as carrageenan), which is used as a functional ingredient in food formulation to improve food consistency, as an emulsifier, and to control texture, flavour and shelf life. It is used in pharmaceuticals, cosmetics, and as a dairy and meat texturiser.⁸ Amongst the most popular species is Gracilaria, which is used as agar to stabilise and thicken food.⁹

Beyond food ingredients, some seaweeds are used as feed for abalone aquaculture and as a feed additive for shrimp and livestock due to its potential to boost immune systems and enhance growth¹⁰. For humans, there are also growing nutraceutical applications.¹¹ Seaweed is also increasingly being used as a base for alternative protein products, including plant-based meat.¹²

In addition, certain seaweeds can contribute to food security as a biostimulant by increasing the ability of plants to absorb nutrients; this aligns with organic farming.¹³ It contributes to plant resilience as well (Figure 1); for example, one seaweed species has been found to improve plant health under saline conditions in the Netherlands, boosting root vegetable yields in the face of sea-level rise.¹⁴ The World Bank highlights that seaweed bio-stimulants represent a USD 1.9 billion opportunity when used as an alternative to fossil fuel-sourced fertilisers and pesticides.15 Another important way in which seaweed contributes to food security indirectly is by providing ecosystem services for fisheries. It provides food and habitat for marine life and is an effective bioremediation tool that enhances water quality by absorbing nitrogen and other undesirable chemicals.

Seaweed farming is also an alternative income source for rural communities, uplifting them – particularly women – from poverty¹⁶ while providing families with a wider variety of foods, including protein products, and thus contributing to better health outcomes.

Seaweed cultivation has been identified in the Intergovernmental Panel on Climate Change (IPCC)’s Special Report on the Ocean and Cryosphere in a Changing Climate as a potential means for biosequestration of carbon dioxide and reducing ocean acidification.¹⁷ However, its potential for decarbonisation is not straightforward.

Through photosynthesis, seaweed absorbs carbon dioxide. A number of companies and research organisations have been experimenting with the cultivation of seaweed to sequester carbon to sink it in the deep ocean floor in exchange for carbon credits.¹⁸ The science of its efficacy and health impacts on marine and aquatic ecosystem is under-studied, however, and researchers and policymakers are cautious about viewing it as a pathway for permanent carbon removal due to the inability to monitor, report and verify.¹⁹ At least one US-based company with USD 70 million in investment, has recently shuttered due to its inability to sustain its operations by sale of carbon credits.²⁰

Carbon captured in seaweed biomass used for consumption (as food, feed or ingredients) or combustion (as fuel or bioplastics) is eventually released, and thus cannot be considered as contributing to decarbonisation. While some carbon is sequestered when fronds break off and sink to the seafloor as sediment, research has found that the amounts are small.²¹ A recent report by the Nature Conservancy and Bain Consulting suggested that, based on current carbon prices (averaging USD 30 per tonne CO2e), carbon markets are unlikely to drive growth in seaweed farming, though this could change if carbon prices were to increase a few-fold.²²

Recent research has demonstrated that the use of Asparagopsis taxiformis and A. armata as feed additives can decrease enteric methane production in cattle by up to 80 percent²³, though long-term studies are needed to confirm this. Cattle farming contributes approximately seven percent of global greenhouse gas emissions, much of this due to enteric methane production. At least one company has started growing Asparagopsis in Vietnam.²⁴

Seaweed can also potentially mitigate carbon emissions by replacing plastics, petrochemicals and other fossil fuel-based products. Red seaweed biomass could, in a distant future, potentially even be used for biofuel production because its productivity (dry weight per unit area per year) is higher than that of wood and agricultural waste.²⁵ Some seaweeds have high lipid and low lignin content suitable for efficient biofuel production, including Gracilaria, comparable to sorghum and sugarcane²⁶; however, past attempts to commercially produce biofuel from seaweed have not been successful. Other studies have shown that Kappaphycus and pure kappa carrageenan have the potential to be made into biofilms that are suitable for single-use packaging²⁷, though these too have yet to be widely adopted.

As seaweed does not require arable soil or chemical inputs, it is seen as an attractive third-generation feedstock to help power a future bioeconomy. However, the lack of availability of sufficient volumes of seaweed at low prices and consistent quality is a limitation. Even though it is now already being added to bioplastics, the current purchase price of raw materials is a significant barrier, as adoption prices for seaweed-based bioplastics are currently 20-40 percent higher than conventional plastics.²⁸ Scale, and the domestic infrastructure for processing at scale, would be critical to develop a seaweed biofuel and bioplastics industry.

Southeast Asia has a longstanding history of seaweed farming and produces more than 32 percent of globally farmed seaweed. ²⁹ Widely cultivated tropical seaweeds have a fast development cycle of approximately 45 days, do not compete with agricultural land, could be grown without fertiliser input, has limited carbon emissions, and can be grown all year round, and is thus ideal as a sustainable produce for Southeast Asia.

Indonesia and the Philippines are the second and fourth-largest seaweed producers in the world, respectively. Malaysia, Vietnam, Cambodia, and Timor Leste also produce seaweed (Table 1). Indonesia alone produces more than 75 percent of global cultivated tropical seaweed.³⁰ Southeast Asia’s seaweed production mainly consists of tropical species of Gracilaria and Eucheumatoids. These are used for direct consumption, feed for aquaculture, or processing into agar and carrageenan. The main export market is China, which is also a major producer, while being a net importer. ³¹

Seaweed is mainly farmed as an alternative income-generating activity for hundreds of thousands in the region. It is commonly farmed by women and is seen as an efficient use of family labour. Due to seaweed farming’s contribution to rural livelihoods and its economic potential, the governments of Indonesia, Philippines, Malaysia and Vietnam have recently been motivated to support seaweed production. Most Southeast Asian seaweed farmers practise a very basic form of cultivation, and any improvements could potentially improve yields significantly.

Indonesia became the second largest seaweed producer in the world, surpassing the Philippines in 2007. It is the world’s major producer of Gracilaria, Kappaphycus alvarezii and Eucheuma denticulatum. The government has introduced a roadmap for seaweed industry development³⁵ by introducing regulations and legislations to empower seaweed farmers and manage and license coastal zones. Indonesia’s Ministry of Marine Affairs and Fisheries (MMAF) has nominated seaweed as one of its top three priority commodities for aquaculture development for 2021-2024 (along with shrimp and lobster); only 2.3 percent of Indonesia’s seascape is used for mariculture, but it has a potential for 12 million hectares. ³⁶ Indonesia is also considering promoting seaweed production for biofuel.³⁷

After years of decline in production due to competition and extreme weather, the Philippines is also priming to expand its seaweed industry. The Department of Agriculture’s Bureau of Fisheries and Aquatic Resources released its National Seaweed (Kappaphycus) Industry Roadmap 2022-2026. According to the Department, seaweed is the primary aquaculture commodity, and more than a million Filipinos depend on the industry. The Philippines Rural Development Project identified seaweed as one of the eight “commodities of national importance” that are priority crops for development and trade.³⁸ The Philippines has 700 000 hectares of farmable area, but only eight percent of it is currently being utilised; the goal is to increase quality and seaweed production by two percent annually.³⁹ Its Seaweed Technology Development Centre is crucial in enhancing seaweed farming through R&D.

Vietnam is targeting to harvest half a million tonnes of seaweed annually by 2030.⁴⁰ Malaysia, on the other hand, is lacking in serious government direction to expand the seaweed industry, even though it was the thirdlargest producer of carrageenan seaweed in the world in 201041, now dropping to the top 20. While R&D has been taking place in Malaysia, it has reportedly not translated into production or resulted in quality improvements for the industry.⁴²

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^{29 Zhang, L., Liao, W., Huang, Y., Wen, Y., Chu, Y., & Zhao, C. 2022. Global seaweed farming and processing in the past 20 years. Food Production, Processing and Nutrition, 4(1), 23.
30 Indonesia Seaweed. 2018. Indonesia Seaweed Infographic. https://www.indonesiaseaweed.com/wpcontent/ uploads/2018/09/Infographic-Seaweed-A4.pdf.pdf
31 Zhang, L., Liao, W., Huang, Y., Wen, Y., Chu, Y., & Zhao, C. 2022. Global seaweed farming and processing in
the past 20 years. Food Production, Processing and Nutrition, 4(1), 23.
32 Zhang, L., Liao, W., Huang, Y., Wen, Y., Chu, Y., & Zhao, C. 2022. Global seaweed farming and processing in
the past 20 years. Food Production, Processing and Nutrition, 4(1), 23.
33 Nguyen Van, T. (2014). Seaweed diversity in Vietnam, with an emphasis on the brown algal genus
Sargassum (Doctoral dissertation, Ghent University).
34 Global Production - Seaweed Insights. (2023, August 8). Seaweed Insights. https://seaweedinsights.com/
global-production/
35 Menteri Hukum dan Hak Asasi Manusia. 2017. Peta Panduan (Road Map) Pengembangan Industry
Rumput Laut Nasional Tahun 2018-2021. https://peraturan.bpk.go.id/Home/Details/108806/perpres-no-33-
tahun-2019
36 Rimmer, M. A., Larson, S., Lapong, I., Purnomo, A. H., Pong-Masak, P. R., Swanepoel, L., & Paul, N. A. 2021.
Seaweed aquaculture in Indonesia contributes to social and economic aspects of livelihoods and community
wellbeing. Sustainability, 13(19), 10946.
37 Indonesia’s Jokowi to push for domestic seaweed processing, including for fuel. 2023. CNA. https://www.
channelnewsasia.com/asia/indonesia-jokowi-domestic-seaweed-processing-fuel-3891606
38 BFAR. 2021. Seaweed Industry Roadmap 2022-2026. Philippines Bureau of Fisheries and Aquaculture,
Department of Agriculture.
39 BFAR. 2021. Seaweed Industry Roadmap 2022-2026. Philippines Bureau of Fisheries and Aquaculture,
Department of Agriculture.
40 Chu Khôi. 2024, January 22. Vietnam targets harvesting 500,000 tons of seaweed by 2030. Vietnam
Economic Times | VnEconomy. https://en.vneconomy.vn/vietnam-targets-harvesting-500-000-tons-ofseaweed-
by-2030.htm
41 Shabudin, M F, Kasim J, Nor A M. 2023. Seaweed farming offers an avenue toward greater food security and
healthier diets in Malaysia. https://iss2023.net/2022/08/22/seaweed-farming-offers-an-avenue-towardgreater-
food-security-and-healthier-diets-in-malaysia/
42 Based on interviews.} 

However, while governments have set out plans to expand their seaweed industries, production volumes and yield have actually been falling in recent years. Indonesia’s seaweed production has been steadily declining since its peak in 2015, and this is mirrored in the Philippines to a lesser extent (Figure 2). The decline is primarily due to deteriorating seed stock quality, which is a result of the multi-decades-long practice of using vegetative propagation for farming. Seaweed production is also suffering from climate change-induced sea-surface temperature warming, immature processing technologies and volatile seaweed prices. ⁴³

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^{43 BFAR. 2021. Seaweed Industry Roadmap 2022-2026. Philippines Bureau of Fisheries and Aquaculture,
Department of Agriculture.}

As the World Bank report highlights, the seaweed industry is ripe for growth. However, it requires enabling policies and actions in Southeast Asia if its people are to reap the benefits.

Indonesia and the Philippines have already formulated roadmaps to expand and develop the industry, including building upon research and development (R&D) to improve cultivars and products, develop nurseries, facilitate access to new seaspaces to expand seaweed farms, empower seaweed farming communities, strengthen value chain infrastructure, develop market linkages, provide training, facilitate technology transfer, and boost industry promotion. Both countries acknowledge that production needs to be modernised and mechanised, especially as farmers are aging. Furthermore, production practices also need to move away from the use of plastic as floatation devices and strings, as these increase product contamination and degrades marine habitats. Other Southeast Asian nations need to put in place similar policies and actions to expand their own seaweed industries.

As a region, however, much can be done to support the growth of the industry so that the benefits are exponential. This aligns with the ASEAN Blue Economy Framework (ABEF) released in 2023, which commits to regional cooperation in the blue economy, prioritising value creation, resilience, inclusivity and sustainability. Seaweed farming aligns with the ABEF’s Blue priority sectors, and when integrated with aquaculture farms, can promote fisheries development and resilience.

Based on the authors’ research, beyond strategies outlined in the ABEF, recommendations for action to further improve the seaweed industry include:

Seaweed has been farmed in Southeast Asia for generations, contributing to the resilience of coastal communities – particularly women – as a vital secondary source of income due to its low barriers to entry and short growth cycle. However, it is not a mere new flavour of the month; it has the potential to bring multi-fold benefits for the region, including multibillion- dollar growth. It is eaten as a food, used as a feed and processed as an ingredient for food, and in pharmaceutical and nutraceutical industries. Seaweed benefits fisheries and marine habitats. It also has potential for decarbonisation, particularly if used to displace fossil fuelderived products such as fertilisers, fuel and plastics.

Southeast Asia could gain economically from these developments, but only if governments in the region take a longer-term view. The focus should be to collaborate and create an enabling environment for seaweeds and their derived products to deliver their sustainability benefits over their fossil-fuel-based counterparts. This would require restructuring the industry to capture downstream processing and manufacturing activities but as operations become more feasible, further investment will be attracted into the industry to improve production quality, which in turn would improve the applications of seaweed-derived products.

Further, while some Southeast Asian nations have plans to grow the industry, the industry could be considerably boosted by regional cooperation in R&D (including for genetic improvement of tropical species) and commercialisation, industry standards and market linkages. This would improve resilience, harmonise standards for product quality, and create enabling environments for downstream industries and market linkages.

Data derived from seaweed farming could also be used for coastal monitoring. These actions align with the ASEAN Blue Economy Framework and to achieve the desired objectives, governments need to support the aforementioned activities. Additionally, given the challenges that climate change poses to coastal communities in the region, enabling the seaweed industry to grow in ways that prioritise local development and resilience to climate change is an opportunity that regional governments cannot afford to miss.