British seaweed is being harvested today and has been for centuries. In the UK, the primary driver is research into algal biofuel technology, but it has a multitude of uses, including bioplastics, cosmetics, medicine ingredients and as a healthy, nutrient-rich and sustainable human ‘superfood’. It has the unique qualities of not requiring land, not competing with people or animals for freshwater resources and growing extremely quickly, while at the same time reducing coastal erosion, improving marine biodiversity and representing excellent carbon sequestration and denitrification potential.
Globally, the seaweed farming industry has nearly tripled in size in 20 years and almost 30m tonnes of seaweed are produced - 95% of which is in Asia.1 In Japan, seaweed appears in 21% of meals.2
Despite our unusually long coastline, we have not yet explored the UK’s potential for seaweed farming and just a handful of sustainable micro-businesses operate in the sector.3, 4
A 2016 Centre for Environment, Fisheries and Aquaculture Science (CEFAS) report indicated that the 2,000 - 3,000 dry tonnes harvested each year in the UK (mostly for food) are ripe for significant growth.5
The Scottish Association for Marine Science (SAMS) describes it as a “greatly underestimated resource”.6
So what needs to be done?
1. Establishing a clear regulatory framework
Licensing is the main stumbling block - there is no regulatory framework. Currently, seaweed farming in the UK operates under a complex web of marine, environmental, and agricultural regulations, often administered by multiple bodies such as the Marine Management Organisation (MMO), the devolved administrations and local authorities. Parliament would need to legislate for a streamlined and transparent licensing process, perhaps through a unifying “Seaweed Farming Act” or amendments to the Marine and Coastal Access Act 2009. Such legislation should simplify site applications, standardise environmental assessments, and introduce a “one-stop-shop” model for permits. Clear guidance on allowable species, environmental monitoring, and farming methods would reduce uncertainty and accelerate project approvals.
2. Financial incentives and investment support
Commercial viability depends on access to capital and predictable revenue streams, meaning in practice, targeted financial measures such as grants, tax credits, or low-interest loans to encourage start-ups and early-stage investors. Inclusion of seaweed farming within existing agricultural or aquaculture subsidy frameworks, for example under the Environmental Land Management (ELM) schemes in England, would incentivise coastal communities to diversify. The Scottish Government already subsidises aquaculture (fish farming) through the Marine Fund Scotland - one round in 2025-26 is making £14 million available for marine economy development.7
Additionally, incubation funding could be directed toward pilot projects that demonstrate scalability and market demand, particularly for high-value products such as bioplastics, pharmaceuticals, and fertilisers.
3. Infrastructure and supply chain development
Seaweed farming requires coastal infrastructure - harbours, processing facilities, cold storage, and transport networks - this means coordination with local authorities and devolved governments to invest in “blue economy hubs” along coastal regions. Support for innovation clusters, research partnerships, and regional development funds would help integrate seaweed farming into existing maritime economies.
Legislation could prioritise public-private partnerships to develop processing capacity, ensuring that harvested seaweed can be transformed efficiently into marketable products. Technique also needs research. Our highly energetic seas are perfect for rapid seaweed growth, but make harvesting more complicated.
4. Research, standards, and skills development
A robust scientific and technical foundation is essential for growth. Funding allocated through UK Research and Innovation (UKRI) and universities for research into genetics, disease management, carbon sequestration, and environmental impacts. Establishing national standards for seaweed quality and safety would also be vital to open export markets and build consumer trust. We should also include seaweed cultivation in our Industrial Strategy and develop a National Centre for Excellence for the sector, driving up relevant apprenticeships and R&D.
5. Market creation and environmental integration
Legislation could recognise seaweed farming as a contributor to the UK’s net-zero goals by quantifying its carbon sequestration and nutrient absorption benefits. Integrating seaweed farming into the carbon credit or biodiversity net gain frameworks would create new revenue streams. A push through procurement policies could increase the use of seaweed-based materials in food, packaging, and agriculture, helping to create stable domestic demand.
Seaweed farming is compatible with marine conservation (although there needs to be research into the potential for the spread of invasive species). It is plausible to encourage Scottish fish farms to convert to seaweed farms, with little re-skilling and vast environmental advantages.
The commercial viability for seaweed farming in the UK would depend on clear rules, financial support, infrastructure investment, scientific backing, and market integration.
More work needs to be done, but it could become a sustainable food source with export potential in the future.
- 1
Seaweed: a future UK farming sector? CEFAS 24th October 2016
- 2
Certified reference material for analytical quality assurance of minor and trace elements in food and related matrixes based on a typical Japanese diet: interlaboratory study J Joshinaga et al, Journal of AOAC International July 2001
- 3
About Us The Cornish Seaweed Company
- 4
First seaweed farm in England is planned for the South Hams South Hams Gazette 13th February 2019
- 5
Seaweed in the UK and abroad - status, products, limitations, gaps and Cefas role CEFAS 22nd April 2016
- 6
Experimental seaweed farms Scottish Association for Marine Science
- 7
Marine Fund Scotland 2025-26 launcheshttps://www.gov.scot/news/marine-fund-scotland-2025-26-launches 10th June 2025
