In the fight against climate change, seaweed could be a surprising — but vital — weapon

Like many coastal communities around the world, people living by the sea in the United Kingdom have harvested and consumed seaweed for centuries.

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’s uses do not end at the dinner table, either: Today, it’s found in everything from cosmetics and animal feed to 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.  

Toward the end of April, a project dubbed the U.K.’s “first dedicated seaweed industry facility” celebrated its official opening, with those involved hoping it will help kickstart the commercialization of a sector that’s well established in other parts of the world.

The Seaweed Academy, as it’s known, is located near the Scottish town of Oban. Funding of £407,000 (around $495,300) for the project has been provided by the U.K. government.

It will be run by the Scottish Association for Marine Science in partnership with its trading subsidiary SAMS Enterprise and educational institution UHI Argyll.

According to a statement from SAMS, one of the academy’s goals centers around stimulating “the growth of UK seaweed aquaculture.” On top of this, the project will look to explore “high-value markets” and use research to boost the worldwide competitiveness of U.K. products.

Rhianna Rees is a seaweed researcher and Seaweed Academy coordinator at SAMS Enterprise. In a recent interview with CNBC, she provided an insight into the type of jobs that went on at a seaweed farm.

“It’s a lot less industrial than it might come across,” she said. “When you think of farming you think of big machinery, you think of mechanical harvesting, and that’s not at all what seaweed farming is about.”

“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.

The apparent simplicity of the process is one thing, but setting up a farm in the first place can be a different story altogether.

“Getting licenses from … the different organizations within England and Scotland — it can be incredibly expensive and time consuming,” Rees said. “So there are major challenges to entering the industry in the first place.”

There were also other factors to consider. “You get storm events, you get maybe years where it doesn’t grow particularly well, fluctuations in nutrients,” she said.

There was innovation on the horizon, Rees went on to note, but it would “take a few years to get to the area where we see the kind of optimization that we need for real scalability.”

Cross country

The U.K.’s interest in cultivating and harvesting seaweed is not restricted to the work being planned in and around Oban.

In the picturesque county of Cornwall on the southwest tip of England, the Cornish Seaweed Company has been harvesting since 2012, providing a glimpse of how the wider industry could develop in the years ahead.

Tim van Berkel, who co-founded the company and is its managing director, told CNBC the firm wild-harvested seaweed from the shores for food purposes.

In 2017, the business supplemented this shore-based harvesting when it started to farm seaweed from spores at the site of an existing mussel farm in waters off Porthallow, a Cornish fishing village. 

“They grow on lines suspended in the water, like buoys really,” van Berkel said, adding that it was “similar to mussel farming.” The business was farming two types of seaweed at the site, van Berkel said: sugar kelp and alaria.

Despite establishing the site at Porthallow, for now the company’s core focus relates to its shore-based harvesting. “That’s really still the main business,” van Berkel said. “There’s five, six, other seaweeds that we harvest … from the wild, from the shores, which is going on year round.”

Other companies looking to make their mark include SeaGrown, which is based in the coastal town of Scarborough, Yorkshire, and is working on setting up a seaweed farm in the North Sea.

Further north, Seaweed Farming Scotland’s operations are located in Oban and focused on the cultivation of species native to the waters there.

The global picture

In 2020, a report from the Food and Agriculture Organization of the U.N. described seaweed farming as being “dominated by countries in East and Southeast Asia.”

The industry is big business, with the FAO separately noting that the seaweed sector generated $14.7 billion in “first-sale value” in 2019.

With the U.K.’s commercial seaweed sector still in its early stages, it has a way to go before it competes on the global stage.

Seaweed farming in Asia can often be large-scale, with sites spread across quite considerable areas, as shown in the above photo of a farm in the province of Zhejiang, China.

The U.S. is also home to a seaweed farming sector, with the National Oceanic and Atmospheric Administration stating there are now “dozens of farms” in waters off New England, Alaska and the Pacific Northwest.

Alongside the commercial products resulting from seaweed farming, there are other benefits too, an obvious one being that it does not require fresh water.

For its part, the NOAA says that “seaweeds are incredibly efficient at sucking up carbon dioxide and using it to grow.” In addition, it notes that “seaweeds also gobble up nitrogen and phosphorus.”

While there are concerns related to permitting in some parts of the U.S., the industry there has expanded in recent years, with the NOAA calling it the “fastest-growing aquaculture sector.”

It adds that 2019 saw Alaska-based farmers produce over 112,000 pounds of sugar, ribbon, and bull kelp. “That’s a 200 percent increase over the state’s first commercial harvest in 2017,” it says.

Worldwide, the industry seems to have been on a rapid course of expansion over the past two decades or so. 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.

It’s not all been plain sailing, however. “Global production of farmed aquatic algae, dominated by seaweeds, experienced relatively low growth in the most recent years, and even fell by 0.7 percent in 2018,” the FAO’s report noted.

And while there would appear to be a multitude of products and benefits linked to seaweed farming, there are also issues those working in the industry will need to address and carefully manage going forward. 

The World Wildlife Fund, for example, notes that, in some instances, species of seaweed have become “invasive when grown outside their natural range.”

The WWF also cites the “entanglement of protected species with seaweed farm rope structures” as a “potential concern” but adds that such an occurrence is unlikely and “no credible documented marine entanglements” have taken in place in 40 years.

Back in Scotland, the Seaweed Academy’s Rees is optimistic for what the future holds. “I think we’re really poised to see the growth,” she said. “I just hope that the hype isn’t hype 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.”