The greenest crop? Seaweed in 2024
Finding a commercial way to grow and harvest seaweed has its challenges, around the world people are finding the way through them.
Interest in farming seaweed has been growing internationally, partly because as a crop, macroalgae has a particularly benign impact on the environment, and partly because science is finding new ways to use the wide range of seaweed species around the world.
In January, a research project to find solutions to the biodiversity crisis in global seaweed stocks was launched by the Oban-based Scottish Association for Marine Science (SAMS) and partners in the UK, Asia and the United Nations University.
The GlobalSeaweed SUPERSTAR project, funded by the UK’s Global Centre on Biodiversity for Climate (GCBC), will involve some of the world’s most prominent seaweed scientists and industry leaders. It aims to produce a global strategy, or “Seaweed Breakthrough”, to be launched at COP31 in 2026 to urgently protect wild stocks.
GlobalSeaweed SUPERSTAR will also involve a core research team of Prof Juliet Brodie of the UK’s Natural History Museum and Prof Lim Phaik Eem of Malaysia’s University of Malaya, as well contributions from the United Nations University Comparative Regional Integration Studies (UNU-CRIS).
Project leader Prof Elizabeth Cottier-Cook of SAMS, a partner of UHI, said: “Despite their significant ecological and economic importance, wild seaweeds receive minimal or no protection through policies or legislation globally… by establishing our ‘Seaweed Breakthrough’ based on robust scientific research, we hope to set out policies that can be adopted at the highest intergovernmental level to help safeguard wild stocks and, ultimately, safeguard the global seaweed farming industry.”
Integrated approach
In June we featured examples of integrated multi-trophic aquaculture (IMTA) in the United States. On the east coast, the University of New Hampshire is using submerged cages to farm sugar kelp, blue mussels and steelhead trout together. The species at the lower trophic level can use the nutrients from fish faeces and uneaten feed, not only taking the nutrients out of the environment where they might otherwise lead to harmful algal blooms, but also providing an additional harvest alongside the fish.
On the west coast, the owners of the Hog Island Oyster Company are growing seaweed, mainly nori, which is popular as a sushi ingredient, alongside their farmed oysters. The seaweed goes to the company’s chain of seafood restaurants in the San Francisco area.
Also in June, Scottish Sea Farms announced that it had teamed up with seaweed-growing venture Atlantic Garden, in a scheme that combines salmon and kelp farming on Loch Spelve, in the Sound of Mull.
The aim of the year-long pilot is to enrich and replenish the marine environment, feeding into the company’s work to minimise any impact from its farming activities.
The farm, which had been fallowed, was chosen as a suitable testing ground in the collaboration between Scottish Sea Farms and businessman and writer Guy Grieve, who ran the Ethical Shellfish Company from Mull and now, through his company Atlantic Garden, plans to produce commercial quantities of sugar kelp, to be used in garden compost.
The seaweed lines, installed in October 2023, produced encouraging growth over the winter, and this month four 90m pens will be stocked with salmon.
Scottish Sea Farms’ Head of Sustainability and Development, Anne Anderson, said: “Seaweed is so beneficial in so many ways for the marine environment. As a plant, it absorbs carbon dioxide, while releasing oxygen. It’s a bit like planting trees to offset your carbon footprint.
“And some of the organic nutrients, nitrogen and phosphorous, from salmon farming are absorbed to help nourish the kelp. It will be interesting to see if we get more seaweed growth once we put the salmon in.”
The Seagriculture EU 2024 conference, the premier event for Europe’s seaweed industry, was successfully held in Tórshavn, Faroe Islands, from 18 – 20 June 2024.
Under the unifying theme “Bridging Continents,” Seagriculture EU 2024 brought together 224 delegates from 25 countries around the globe. Representatives from more than 123 companies and institutions actively engaged in discussions, networking, and knowledge sharing, underscoring the global interest in seaweed farming and its diverse applications.
As well as presentations from international experts, Seagriculture EU 2024 also included a site visit hosted by Ocean Rainforest, one of the largest seaweed cultivators in Europe.
The event’s North American counterpart, Seagriculture USA was held in Ketchikan, Alaska, from 11-12 September 2024. Under the theme “Exploring New Frontiers,” Seagriculture USA 2024 united nearly 200 stakeholders from 10 countries to share knowledge and ideas, steering the future of the seaweed industry towards sustainable and economically viable paths.
In July, the company behind an ambitious seaweed farm in the North Sea said it will be the world’s first offshore facility of its kind on a commercial scale.
North Sea Farmers planned to open a seaweed farm, co-located with the Hollandse Kust Zuid (HKZ) wind farm, about 18 kilometres off the coast of Scheveningen in the North Sea.
HKZ, owned by Vattenfall, BASF, and Allianz, consists of 139 turbines. It generates electricity equivalent to the typical consumption of 1.5 million Dutch households.
North Sea Farm 1, created by North Sea Farmers with funding from Amazon’s Right Now Climate Fund, is a floating farm located between wind turbines where seaweed cultivation can be tested and improved. Scientific research will also be conducted on site into the potential of seaweed farms to capture carbon.
By locating the farm in previously empty space between turbines, the company says, the project will be able to expand seaweed cultivation in the otherwise heavily used waters of the North Sea.
In August we reported that Scottish-based company Seaweed Enterprises was raising finance to build the UK’s largest multi-species seaweed processing hub – and has rolled out a new brand identity for its products.
The company’s new brand is “House of Seaweed” and its plan is to unlock the European bottleneck curtailing growth by stabilising seaweed at scale and producing quality bulk ingredients. Its plans include development to be the UK’s first multi-seaweed processor accredited under the BRCGS food safety standard scheme and able to handle any seaweed species by enhancing production capabilities and supporting its own journey to net zero targets.
In August last year, Seaweed Enterprises acquired the assets of Fife-based Mara Seaweed, which had been placed in the hands of administrators.
Seaweed Enterprises was established by experienced CEO Pete Higgins, along with the senior team from Mara Seaweed – Arnie Sathiy and Clare Dean – who have several years’ practical and commercial experience in the seaweed industry.
Award winners
The Scottish Seaweed Company was a winner in two categories in the Scotland Food & Drink Excellence Awards, which were held on 9 October.
Two products in the company’s Shore range of snacks were declared best in class: its Peking Duck Seaweed Chips were named Healthier Choice Product of the Year, while Shore Sweet Sriracha Seaweed Chips won in the Snacks and Accompaniments category.
In November we reported on the ongoing row over plans to create the UK’s biggest seaweed farm off the coast of Cornwall.
Despite enlisting celebrity firepower, campaigners have not (yet) managed to stop the project.
Biome Algae alongside Camel Fish Limited filed a double application with the Marine Management Organisation (MMO) for two 50-hectare seaweed farms in Port Quin Bay, between Polzeath and Port Isaac, in July 2023, with a 50-year licence running until 2073.
The Cornwall-based applicants say the cultivated seaweed, native to the UK, will provide food, low-carbon animal feed, fertiliser, and biomaterials to replace single-use plastic and take-away cartons.
Moreover, they add, farming seaweed does not require freshwater, land, feed, fertilisers, does not produce waste, and can sequester carbon at a rate six times that of trees, as well as restore habitat and increase marine life.
Each would deploy 144 160-metre longlines in the bay during September over two to three years, with seeded lines installed in October and early November each year, when sea temperatures are favourable. Harvesting would take place annually in April or May, when growth is maximised but biofouling is avoided. Over 1,720 buoys with marker lights on at night would be installed.
The initial licence application was felt to have not done enough to bring it to public attention. When it was re-submitted with wider publicity, it attracted a storm of objections and it looked as if the project was dead. The MMO said the application had cleared its initial hurdle, and, as regulator, will be consulting further with the public – so watch this space.
In November, the Scottish Seaweed Industry Association celebrated its first 10 years at the annual SSIA Conference, in Oban.
Delegates heard an address from Mairi Gougeon, Cabinet Secretary for Rural Affairs, Land Reform and the Islands, who said: “I can assure you that the Scottish Government has every confidence in Scotland’s seaweed growing and harvesting community, which is a community of innovators in an industry which is playing a very important part in our greener, more sustainable future.”
It was an expression of faith that this industry, which still has many hurdles to overcome, still offers great potential.
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