Seaweed Could Become a New Raw Material in Future Material

2026.05.25

Amelie Silfverstolpe reflects: I recently returned from Blue Hub Halland’s gathering in Glommen, outside Falkenberg, and from a workshop in Lund held as part of Axfoundation’s Seaweed Materials Initiative. What became clear during those days is that the future of seaweed as a material will not be determined by a single innovation. It will depend on how successfully we connect cultivation, material development, industrial needs, and market demand.

During the meetings, growers, researchers, material developers, investors, and industrial stakeholders gathered to discuss seaweed as a material for the future. The conversations brought both new insights and optimism. Not because seaweed is a simple solution – but because marine biomass could become an important complement in the transition toward more biobased materials.

From Raw Material to Function

We are facing a major material transition. Fossil-based and resource-intensive materials need to be replaced, but switching raw materials alone is not enough. The materials of the future must work in practice, be scalable, fit into circular systems, and ideally avoid competing with food production, land use, or freshwater resources.

This is why seaweed is so interesting. It can be cultivated in the ocean without competing for agricultural land and without requiring freshwater, fertilizers, or pesticides. During growth, seaweed absorbs nutrients such as nitrogen and phosphorus, which may help reduce eutrophication and improve water quality. It also captures carbon in its biomass while growing. The long-term climate impact, however, also depends on how the biomass is harvested, used, and whether it replaces other materials.

In Sweden and the Nordic region, seaweed – including species such as sugar kelp – remains a relatively small and underutilized biomass, despite favorable biological and geographic conditions for cultivation.

But the truly interesting part begins when we move from biomass to functional materials. Sugar kelp contains components such as alginate, cellulose, laminarin, mannitol, proteins, and minerals. Simplified, alginate can contribute to gel and film formation, cellulose can provide structural properties, and minerals may contribute natural flame-retardant characteristics. This opens possibilities for new types of soft films, textile fibers, coatings, and rigid biocomposites for applications ranging from interiors to fashion and built environments.

Seaweed therefore should not simply be described as another “green substitute.” Its real potential lies in the raw material’s own unique properties and functionalities.

At Axfoundation’s material workshop at Torsåker Farm, early tests have shown promising indications of flame-retardant properties in seaweed-based building materials. This is particularly interesting because fire safety requirements are critical in construction and interior materials. Sustainability alone is rarely enough as an argument. Future materials must also perform.

Seaweed Materials Initiative brings together the entire value chain to develop standards, processes, and prototypes that enable a scalable value chain – from ocean to finished product. Photo: SweKelp AB

Facts about Sugar Kelp

What is it? Sugar kelp (Saccharina latissima) is a brown algae species that thrives in cold, salty Nordic waters. It can be cultivated on ropes in the ocean and is typically harvested in the spring.

Why is it interesting? It can be cultivated without agricultural land, irrigation, or pesticides, while also absorbing nutrients during growth. As a material feedstock, it is particularly interesting because it contains alginate, cellulose, laminarin, mannitol, proteins, and minerals. Different components of the biomass can therefore be used in applications such as films, fibers, coatings, biocomposites, and moldable materials.

What are the challenges? Sugar kelp consists largely of water, and its quality can vary depending on season, cultivation site, and post-harvest handling. For industrial use, it requires consistent raw material quality, efficient stabilization and drying, resource-efficient processing, and sufficient demand to enable the entire value chain to scale.

Europe Turns Its Attention to the Blue Bioeconomy

Interest in seaweed is growing rapidly across Europe. At the same time, Europe still accounts for only a very small share of global seaweed cultivation, which today is dominated by Asia.

According to the Seaweed for Europe Coalition, the European seaweed market could grow to approximately EUR 9 billion by 2030 and create up to 115,000 jobs – provided the sector develops sustainably and at sufficient scale.

For Sweden, this represents an opportunity not only to follow the development but to help shape it. We have coastlines, favorable cultivation conditions, strong materials research, and industries searching for new biobased alternatives. Seaweed will not replace forests or all fossil-based materials, but it could become an important complement. Forestry remains central, but it cannot carry the entire material transition alone.

Sugar kelp absorbs carbon dioxide, nitrogen, and phosphorus, helping reduce eutrophication and improve water quality. Photo: Nordic SeaFarm

From Potential to a Functioning Value Chain

If seaweed is to become an industrial material feedstock, fascination alone will not be enough. Cultivation is still small-scale, raw material quality varies depending on season and growing conditions, and the biomass itself is demanding: high water content, odor, salt, and mineral levels can quickly increase processing costs if stabilization and drying are not handled efficiently.

It is a classic chicken-and-egg problem. Growers need demand in order to scale production. Industry needs volumes and consistent quality in order to develop products. Material developers need stable fractions. Brands need solutions that meet requirements for functionality, design, price, and sustainability. Investors need to see a credible path to commercialization.

This is why the entire value chain must evolve simultaneously. Standards, quality assurance, smarter fractionation, testbeds, prototypes, business models, and sustainability data all need to work together. Through the Seaweed Materials Initiative, growers, researchers, material developers, brands, and industrial stakeholders are collaborating to explore what is required for Swedish-grown sugar kelp to become a competitive raw material for biobased materials.

At Axfoundation, we are working hands-on with the question: where can seaweed create the greatest value as a material? In our material workshop, we are testing seaweed in moldable cellulose composites, stabilization and drying processes, flame-retardant applications, and other areas where industry is seeking efficient processes and biobased alternatives.

Much still remains to be proven: durability, moisture resistance, mechanical performance, process economics, circularity, and actual climate benefits compared to today’s materials. It is not enough for a material to be biobased. It must be the right material in the right place, with the right functionality and the right surrounding system.

When I think back on the days in Falkenberg and Lund, it is precisely this combination that stays with me: growers testing new methods despite storms and ice, researchers deepening our understanding of seaweed chemistry, and material developers translating functionality into practice.

Seaweed’s future will not be determined by a single innovation. It will depend on whether we succeed in building the entire chain – from ocean to finished product.

Because the materials of the future are not only about what we manufacture. They are about the systems, collaborations, and markets we build around those materials. That is where the real transition takes place.

// Amelie Silfverstolpe, Project Manager for Future Material, Axfoundation