seaweed

The Quest For Sustainable Seaweed

Swaying below the waves of a remote North Atlantic fjord are layers of rope held up by buoys and fixed to the ocean floor with anchors; the ropes themselves have been seeded densely with seaweed crops. A less dazzling landmark than the natural beauty around it, perhaps.

But offshore deep-water structures like these in the tiny Faroe Islands tell a broader story of how once-remote coastal fishing communities are fast adapting and innovating to cater for the rising global craving for seaweed — a demand fueled by an enthusiastic and growing chorus of scientists, farmers, engineers and environmentalists who love this slippery stuff. They, and others see seaweed as an exciting source of energy, proteins, biodegradable plastics, fertilizers, clothes, or pharmaceuticals.

This craze is about far more than the globalisation of seaweed-rich Asian cuisine like sushi. Look closely, and you’ll spot a widening wave of seaweed-infused products is already washing through the global market.

Fancy a pair of seaweed sneakers? Here you go. Face cream? Slather it on. Edible and biodegradable water bottles? You’d know about those already if you’re the hale and hearty sort who ran this year’s London Marathon and had to gobble down a few of these liquid blobs en route. How about just a Kelp smoothie? Coming right up, and there will be much more where this all came from.

One report by business intelligence firm Markets and Markets predicts the commercial seaweed market is set to almost double from its 2017 value of just over $13 billion. A recent Future of Food Report commissioned by British supermarket chain Sainsbury’s is similarly optimistic; it reckons seaweed “has the potential to alleviate environmental pressures, absorbing massive quantities of carbon and providing habitats for water-filtering species.”


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Experimental livestock farmers are just as excited as Sainsbury’s, but for slightly different reasons. Some are already feeding it to their chickens, pigs, and cows. These farmers are not mavericks; they are taking their cue from research showing that seaweed-infused diets lead to lower methane emissions and fewer udder infections, reducing the need for antibiotics and leading to healthier milk in greater quantities.

With the world’s population approaching 10 billion, humans will likely turn ever more attention to farming in the ocean — which counts for 70% of the earth’s surface but only a fraction of our food. Ancient seaweed habits offer hope of a return to old ways; archaeological evidence abounds of how seaweed has always been a problem solver for humanity.

Seaweed expert Dr. Ole Mauritsen reckons early humanity’s foraging for seaweed was even as crucial in the evolution of our cerebral cortex as fishing: “The micronutrients in seaweed: These are the things the brain feeds on,” he says by phone, noting how some seaweed has a healthy mix of Omega-3 and 6 fatty acids, as well as significant levels of potassium, magnesium, and iodine. Recent research by Dr. Mauritsen and others has suggested that a seaweed-rich diet can counter depression, mitigate Alzheimer’s disease, and possibly improve sexual function.

Seaweed’s secret

Seaweed’s secret lies in its ocean provenance. Growing faster than terrestrial plants, seaweed absorbs and stores surrounding nutrients within a jelly-like cell structure of polysaccharides. Vary temperature or sunlight, and seaweed will adapt its composition for optimal photosynthesis and survival.

Then again, Dr. Mauritsen, who is a gastro-physicist and professor of culinary innovation at the University of Copenhagen, reflected that talk of better health or saving the planet is often not enough: “You can use all the sustainability buzzwords you want, but if it’s not tasty, people aren’t going to eat it.”

Fortunately, like their counterparts in Asia, European and American consumers, he said, “are starting to discover that seaweed is actually tasty.”

Aside from the rising global popularity of Asian cuisine, some restaurants in Europe and America are already championing a seaweed diet. In Amsterdam, the Dutch Weed Burger joint introduces thrill-seeking tourists to fast-food seaweed. “They think they’ll get high,” explained Larissa van Nimwegen, a chef at the Joint, standing in front of a bright sign that reads, “Eat Weed. Live Long.”

Unlike the marijuana-touting cafes scattered across the Dutch capital, the weed delicacies on the menu here won’t leave anyone glazed-eyed or giggling. Tucked between two green buns, the “Dutch Weed Burger” is a vegan soy patty mixed with Royal Kombu, a seaweed species belonging to the kelp family. The green buns themselves are sprinkled with flecks of microalgae known as Chlorella Sorokiniana. The dish is made more special by its sourcing difficulties: the Joint’s seaweed supply chain singularly relies on two hardy, idealistic women who wield machetes and bring in produce from the windy, thankless North Sea.

The production challenge

Faced with widening demand, engineers in places like the Faroe Islands are grappling with how to build and sustain offshore seaweed farms, buoyed by how this sloppy stuff is literally coming into fashion onshore.

“I love its softness,” said Faroese fashion designer Sissal Kj. Kristiansen, gliding her hands over a hooded blue dress of cotton and seaweed she designed to accompany her handbag of salmon leather. Her folklore-inspired design, called “Seal Lady,” featured in a wave-rocked, wind-swept catwalk last summer aboard two ships, watched by several of Europe’s fisheries ministers in thermal coats.

“In here is captured carbon,” Ms. Kristiansen explained of her dress, praising seaweed’s global role as a prolific photosynthesizer. Seaweed, a macroalgae, along with its tinier counterpart, microalgae, absorb more carbon dioxide and release more oxygen than the world’s rainforests.

“I’ll never understand how they make that,” she laughed, adding that she is now on the search for seaweed-infused wool.

Wool will not be hard to find on an archipelago with far more sheep than humans, but the scientists themselves are also still puzzled over how to create these sorts of seaweed products, and others, in a way that is financially and ecologically viable. The words “possible” and “potential” are everywhere in the world of “algae-neering.”

By and large, the feats of science and engineering required for large-scale seaweed cultivation remain elusive in Europe and North America. Nearly all seaweed on the market today comes from low-wage, labor-intensive, monoculture farming in the shallow waters off East Asia. The reliance on only a few species makes the trade highly vulnerable to pests and disease. Also problematic in China, in particular, is the regulatory laxity and the liberal use of environmentally-harmful pesticides. In Japan, the radioactive fallout from the Fukushima nuclear disaster has also had regional repercussions on production in the Pacific.

One other scaleable option is on-shore production facilities, like at the Texas-based algae startup Iwi,  which offers greater condition controls preferable for pharmaceuticals. There also remains the option of harvesting wild seaweed, an option already explored for centuries as a low-grade fertilizer for land crops in all sorts of maritime communities and subject to considerable expansions in places like Brittany, Nova Scotia, and Norway in recent decades. But there are few guarantees of product consistency in the wild — a drawback for standardised food growing, not just pharma. Besides, the trawling is tricky and wasteful, and the practice scrapes the oceans of their life-source.

The trouble with Powerpoint engineering

At a scientific conference on “sea-griculture” in The Hague back in 2017, the offshore seaweed farming dream seemed further adrift on the horizon, full of earnest theoretical debates on the viability of new automation to bring the seaweed onshore, or whether it could be “ranched” with underwater drones effectively acting as cowboys, or whether genetic modifications could or should be made to increase yields. Between servings of seaweed tea, a German scientist outlined the engineering difficulties for any cultivation structure beyond niche foraging. Combating wear and tear from storms and strong currents demanded ingenious solutions, he cautioned, describing various complex forms of Integrated MultiTrophic Aquaculture.

Midway through the presentation, a bellowing Faroese voice interrupted from the back of the auditorium. A wild-haired Olavur Gregersen, leaning on a pair of crutches after breaking his leg offshore, was having none of the naysaying.

“We’ve been in contact ever since,” he said of his heated exchange with the German engineer, who he later invited to see his stretch of deep-water seaweed rigs at Ocean Rainforest, Mr. Gregersen’s seaweed startup.

Veering past rivulets, waterfalls, and grass-roofed cottages last spring, Mr. Gregersen clicked his windscreen wipers into action. “I can follow his skepticism,” he added, but noted that his new German acquaintance had fallen into the trap of “Powerpoint engineering: You simply over-engineer the things you want to do.”

His company, he said, kept things simple and stuck to the traditional line-fishing knowledge that remains palpable in every aspect of Faroese society. “Here the ocean is in our veins,” he intoned, glancing out at yet another fjord.

The Faroe Islands offer ideal ocean conditions for wild seaweed: clean, cool, nutritious, nitrate-rich waters, and limited variations in temperature. This does not mean it is easy for offshore cultivators, who must endure frequent storms and raging currents.

“We were using whatever forces we had within us to hold our lines,” Mr. Gregersen recalled of early attempts at rigging a seaweed farm in the open ocean, which involves a delicate process of infusing long ropes with seeds, before lowering them into the water, secured between buoys and anchors.

Also tough to navigate is the regulatory environment. Large-scale seaweed farming is such a novelty here that Ocean Rainforest had been operating for years under a salmon fishing license.

Parking next to a derelict fishery in the tiny Faroese village of Kaldbak, whose fjord-farmed salmon had been prone to lice infestations, Mr. Gregersen offered a tour of what he claims to be Europe’s first large-scale open-ocean seaweed refinery. Its few renovated rooms resembled a Copenhagen tech startup, while other back rooms served as laboratories and storage space for second-hand equipment from the local fishing industry, which is responsible for approximately a quarter of the country’s GDP and 99% of exports from this Nordic archipelago.

“I got this machine from an old fish processing plant,” Mr. Gregersen remarked, pointing to a conveyor belt. Instead of salmon or cod, seaweed now rolls along to be washed, squelched, siphoned, and then dried or frozen for export. His ability to infuse new purpose into old appliances was shaped by stints as a fisherman clothes salesman, oil consultant, founder of telecommunications and VR simulations companies, and, finally, renegade seaweed cultivator.

This Faroese jack of all trades emphasized, “We have to come up with solutions that use as little manpower as possible. It is a natural thing for us,” referring to his native archipelago’s tiny population of 50,000.

Seaweed Agnes

Long before seaweed was remotely fashionable here, Agnes Mols Mortensen stood apart as a lone macro-algal biologist. Locals call her “Seaweed Agnes.” Others know her as the “Seaweed Queen.”

Her seaweed spark, first lit by a schoolteacher helping her name 260-odd species of native seaweeds, has had to evolve with the world’s growing fascination with her subject matter.

“I find myself missing the old macroalgal world,” she sighs. “And now the whole entire world is starting to get interested. I didn’t plan for that to happen.”

Although Dr. Mortensen is in some ways excited by the growing public interest, she feels unmistakable anxiety borne of a scientific idealism.

“I think we need to figure out what happens to the ecosystem when we deploy an entire macroalgal farm on the surface,” she warned. “We are forgetting about the plants living beneath.”

In light of this, the scientist has tried to establish her own company based on strong environmental principles. She and her brother have set up a rig to sell locally foraged, cultivated seaweed. But economically, it is the rigs of Mr. Gregersen causing more of a stir. He is already taking his concepts to other seas, currently conducting feasibility studies in the nutrient-rich waters off California, at the Catalina Sea Ranch.

Meanwhile, Dr. Mortensen admits to finding the business side harder than focusing purely on research. More seaweed aficionado than entrepreneur, she has sought to raise awareness through local seaweed tours.

“No one knows a single species, and this is the Faroe Islands,” she said, comparing how people typically know at least several species of land plants. “They’ve been stepping on them their entire lives.”

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