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Seaweed could be a vital ingredient in the fight against climate change


As with many other coastal areas around the globe, the British have lived by the ocean for generations.

In Wales, Welsh laverbread — made from cooking a type of seaweed called laver — is a culinary delicacy so revered that it enjoys Protected Designation of Origin status.

Seaweed is used in many other ways than just at dinner. It can be found in cosmetics, animal feed, and even gardening products. and packaging.

With concerns about the environment, food security and climate change mounting, this wet, edible treasure of the sea — of which there are many varieties and colors — could have a major role to play in the sustainable future of our planet, and the U.K. wants in on the act.  

A project known as the U.K.’s first dedicated seaweed industry facility was officially opened at the end April. Those involved hope it will spur the growth of an already established sector in other parts.

It is situated near Oban, Scotland. Funding of £407,000 (around $495,300) for the project has been provided by the U.K. government.

It will be managed by the Scottish Association for Marine Science, in collaboration with SAMS Enterprise (trading subsidiary) and UHI Argyll (educational institution).

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SAMS stated that one of their goals is to encourage “the growth in UK seaweed aquaculture.” The project will also explore high-value markets and conduct research in order to increase the global competitiveness of U.K. goods.

Rhianna is both a Seaweed Academy Coordinator at SAMS Enterprise and a researcher on seaweed. She gave a glimpse into what it was like to work on a seaweed farm in a recent interview for CNBC.

It’s much more industrial than people might believe,” she stated. Seaweed farming does not involve large-scale machinery.

“When you look at it from the outside, all you can see are buoys in the water and then under the water are these long lines of rope with … huge swathes of seaweed,” she went on to explain.

“When you want to harvest it, you go in and you get the rope and you pull it into the boat — and that’s basically it,” she said.

It is easy to see the simplicity in this process, but it can be difficult to actually set up your farm.

“Getting licenses from … the different organizations within England and Scotland — it can be incredibly expensive and time consuming,” Rees said. It is difficult to get into the business.

You should also consider other factors. She said that after storms, it can take years for the plant to grow well.

Rees noted that there was some innovation in the future, however, it would take “a few years” to reach the point where the optimization we require for true scaling.


There is more to U.K. interest than just Oban-area work.

The Cornish Seaweed Company, located in Cornwall, on the southwest coast of England, has been harvesting seaweed since 2012. It offers a glimpse into the future of the industry.

CNBC’s Tim van Berkel is co-founder and managing director of the company.

The business added to this shore-based harvesting in 2017 when it began farming seaweed using spores on the spot of an existing mussel farm off Porthallow. This Cornish fishing village is known as Porthallow. 

van Berkel explained that they grow on suspended lines in the water. It was “similar to mushroom farming.” van Berkel explained that there were two types of seaweed being grown at the location: sugar kelp as well as alaria.

Porthallow is the new site, however the main focus of the company right now remains on its shore-based harvesting. Van Berkel stated, “That’s still our main business.” We harvest five, six more seaweeds from the wild and from shores all year.

SeaGrown is another company looking to establish itself in Scarborough, Yorkshire.

Seaweed Farming Scotland is located further north in Oban. They focus on cultivating species that are native to those waters.

The global picture

View from the sky of workers at Zhejiang, China’s seaweed farm. November 24, 2021.

Jiang Youqing | Visual China Group | Getty Images

According to the U.N. Food and Agriculture Organization, seaweed farming is “dominated by East and Southeast Asia” in 2020.

This industry is very lucrative. The FAO also noted that seaweed was a significant sector. generated $14.7 billion in “first-sale value” in 2019.

The U.K.’s seaweed industry is still very young and it will need to continue growing before competing on the international stage.

As you can see, seaweed farming in Asia is often large-scale and spread over vast areas.

A seaweed farming industry exists in the United States. The National Oceanic and Atmospheric Administration states that there are “dozens” of such farms located off New England and Alaska.

There are many benefits to seaweed farming beyond the obvious commercial product.

According to the NOAA, “seaweeds can absorb carbon dioxide very efficiently and use it to grow.” The NOAA also noted that “seaweeds” consume nitrogen as well as phosphorus.

Although there is concern about permitting in certain areas of the U.S.A, there have been many positive developments in the sector. The NOAA has called it the fastest-growing aquaculture industry.

The report adds that Alaskan farmers produced over 112,000 pounds each of bull kelp, sugar ribbon and ribbon in 2019. According to the report, this represents a 200-percent increase on 2017’s initial commercial harvest.

Over the past 20 years, there has been a steady increase in the global industry’s production. The FAO’s report said global marine macroalgae — another name for seaweed — production had risen from 10.6 million metric tons in 2000 to 32.4 million metric tons in 2018.

However, it has not been all plain sailing. According to the FAO’s 2018 report, “Global farmed aquatic alga production, with seaweeds as the dominant species, saw comparatively low growth over the last few years. It even declined by 0.7 percent in 2018.”

This aerial view shows a location used for seaweed cultivation in the waters of Bali, Indonesia.

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Seaweed farming offers many benefits and products, but there are still issues that must be addressed and managed carefully by those in the sector. 

According to the World Wildlife Fund, some seaweed species have been declared “invasive” by being grown in areas outside of their natural range.

WWF also refers to the “entanglement with protected species using seaweed farm ropes structures” as a potential concern, but says that it is not likely and has “no credible documented maritime entanglements” in over 40 years.

Rees from the Seaweed Academy in Scotland remains optimistic about what the future has in store. Rees stated that she believes we are well-positioned to witness the growth. “I hope it’s not hyped for the wrong reasons.”

“And as long as we’re all … working together to get the message and to get the training and to get development right, along with support from governments and investors, then we’ll see something that’s really beneficial for the world, really sustainable.”