Kelp: The sustainable superfood coming soon to a plate near you

Kelp’s potential as a commercial crop is finally being recognized — and, as kelp forests vanish worldwide, so is its importance in coastal ecosystems 

  • Published Sep 10, 2021
  • Updated Apr 19, 2022
  • 2,515 words
  • 11 minutes
Sea lion swimming among a kelp forest
A sea lion is silhouetted by sun rays slanting through a kelp forest. Kelp’s potential as a sustainable food is finally being recognized — but scientists are discovering many species are endangered. (Photo: Maxwel Hohn)
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Bill Collins remembers when lobster was a worthless bycatch. “Growing up in Newfoundland, no one wanted to eat it,” he says. Kelp was even worse: fishermen called patches of it “devil’s apron.” Its long, flat strands fouled nets, jammed up propellers and marked rocky, dangerous waters. But just as lobster has become a delicacy, Collins thinks kelp’s day is coming. 

A few years ago, the Vancouver Island Economic Alliance hired the marine geologist and entrepreneur to find the best industries for attracting foreign investment to the area. He considered everything from eco-tourism to clean-tech, but one option was too good to hand over to someone else — kelp farming.

Kelp is a type of seaweed that grows in long strands stretching from depths of more than 50 metres right up to the surface of the ocean. Like their landlubber counterparts, kelp grow in forests of trunks that both shade the sea floor and create multi-canopy habitats that harbour some of the richest biodiversity in temperate waters. Wave energy undulates the trunks and leaves back and forth, as the energy is absorbed by the kelp, protecting coastlines and creating calmer habitat for birds and mammals to shelter in. Many biologists agree kelp forests are one of the most important habitats for marine wildlife in all the Canadian oceans. 

Those same factors make kelp farming attractive. “The opportunity is tremendous,” Collins says. “Canada is in the sweet spot for brown kelp. And farming it here can check a number of boxes.”

The best use for kelp, Collins says, is food. It’s not the same as nori — the dried sushi paper — but it has many other uses. Ground kelp adds an umami flavour boost to salads and all kinds of soups and noodle or rice dishes, or can be rehydrated and sliced. Almost every type of seaweed is edible. Today, more than 99 per cent of seaweed is produced by seven Asian countries, including China and Indonesia, where it’s eaten raw in salads, cooked in soups and dried in seasonings. Consumed in much smaller quantities on this side of the Pacific, the North American market imports 95 per cent of its seaweed from abroad, worth more than $60 million every year, according to a study by the Island Institute, an economic development non-profit based in Maine. 

But demand is growing. As appetites shift to meat alternatives, foods grown in the sea present an untapped opportunity — and kelp is rich in micronutrients, vitamins and antioxidants, some of which are available elsewhere only in meat. A 2016 World Bank report estimates that if seaweed farming, including kelp farming, continues to grow by up to 14 per cent per year, it could add 10 per cent to the world’s present supply of food by 2050 (and this whole harvest could be grown in 0.03 per cent of the oceans’ surface area). 

That’s just the beginning. Kelp is already used on land as a farm fertilizer and soil enhancer and in foods as a thickener and emulsifier. A United Nations paper found a long list of other potential uses. Added to cattle feed, it can reduce methane emissions (a potent greenhouse gas source), plus growing it is less carbon intensive than alternative land-grown foods, like corn and hay. Because kelp absorbs 20 times as much carbon dioxide as the same area of cultivated land, there’s potential for industrial-sized, offshore kelp farms to sequestrate carbon. Like corn, kelp could replace petroleum as a biodegradable source of plastic, or a biofuel like ethanol. Grown in polluted areas, it purifies ocean waters. It’s already used to make vitamins — particularly iodine — and it may be a source of undiscovered pharmaceuticals. 

Altogether, it was enough to convince Collins and some partners to start a kelp farming business: Cascadia Seaweed. But what gets Collins really excited is that, done right, kelp farms could actually benefit the coastal ecosystem. Unlike land crops, once seeded, kelp requires no watering, fertilizing, pest control or other inputs, he says. And the farms actually create natural habitat. “Kelp farming is one of the few industries that the more we do it, the better for the planet,” says Collins.

But just as the world is realizing its importance and potential, researchers are also discovering that many types of kelps and seaweeds are endangered. Kelp are disappearing around the world, including in B.C. and Nova Scotia waters. In Canada there’s a rush to find out why — and learn more about a little-known, but vital, seaweed. 

Cascadia Seaweed’s kelp farming operation in Barkley Sound on the west coast of Vancouver Island. (Photo courtesy Cascadia Seaweed)
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Kelp’s sudden vogue is nothing new to Louis Druehl. A lot of what the world knows about kelp came from this Canadian botanist, who has been studying kelp for almost six decades — and continues to grow, study and sell seaweed from his Bamfield, B.C., home. Druehl is the author of a popular field guide on kelp and has been teaching, and proselytizing, about kelp for 35 years. He was first attracted to what he originally thought was a plant as a PhD student at Simon Fraser University in 1965. “It caught my attention because it was so poorly understood,” he says. “It still is.”

Kelp, he discovered, is not a plant but a protist — the most diverse group of organisms ranging from predominantly single-cell, microscopic diatoms to multicellular seaweeds. More specifically, kelp are brown algae seaweeds that live in cold waters around the world. More than two dozen different species of kelp live in Canadian seas, from Vancouver Harbour to the Gulf of St. Lawrence and throughout the Arctic. They range from small, rock-hugging bushes to B.C.’s underwater forests of giant kelp, which reach up to 25 metres in length and can grow a quarter of a metre a day.  

Whether towering or tiny, wherever they grow kelp are integral to the coastal ecosystem. More than 100,000 invertebrates from 350 species can live on a single strand of kelp. The trunks, or stipes, provide shelter and food for fish, including juvenile salmon and herring. Crabs and snails live right on the blades, the leafy fronds that often reach the surface, where sea otters anchor themselves to rest. Bivalves thrive in the rocks and sand around their holdfasts, the root-like structure that keeps kelp attached to the ocean floor. 

Humans have harvested kelp for thousands of years and farmed it for at least 1,000 years on the Asian side of the Pacific Rim. In fact, the “kelp highway” theory proposes that the first humans to arrive in America more than 13,500 years ago were sustained by kelp. More recently, kelp hasn’t been terribly mainstream in North America, although at least one seaweed cookbook came out of the 70s — only Indigenous, and some settler, wild harvesters were using kelp on a regular basis. But when the B.C. government wanted to develop a kelp farming industry in 1980, it hired Druehl to modify the commercial practices used in Asia to Canadian waters. The method he helped develop — seeding kelp on a rope sunk between two floats — is still how farms grow it today. 

During the height of the oil crisis in 1982, General Electric tasked him with figuring out how to maximize kelp production to turn it into fuel. “Kelpanol,” as Druehl likes to call it, worked, but the conglomerate lost interest when oil prices fell a few years later. 

Those experiences led to some of the first Canadian commercial kelp farms, including Druehl’s own Canadian Kelp, founded in 1983. The company continues to sell edible kelp products, but mostly Druehl and his small team are consultants, helping businesses around the world learn how to cultivate kelp. In Canada, there are now a handful of companies on the east and west coasts. In recent years, interest in cultivating kelp has increased and Druehl’s business has shifted more towards seed production: “the hardest part of growing kelp,” he says. Lately, the seeds are not just for farms. He’s also developing methods of planting wild kelp to help with restoration and replanting efforts.

Kelp absorbs wave energy, creating a calmer habitat for coastal mammals, birds and fish. (Photo: Maxwel Hohn)
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Around the world, kelp is declining. A 2016 study by researchers at Dalhousie University in Halifax found kelp beds along a 100 kilometre stretch of the Nova Scotia coast have shrunk by 85 to 99 per cent in size in the last 50 years. In B.C., where First Nations have always harvested kelp, they “were seeing kelp forests that were there for decades suddenly disappear or shrink,” says Rebecca Martone, a kelp forest ecologist and a co-lead in the Marine Plan Partnership (MaPP), a collaboration between the B.C. government and 17 First Nations. The project, started in 2019, aims to study the distribution of kelp along the coast from northern Vancouver Island to Alaska to better understand its resilience to climate change and figure out what a sustainable harvest could look like. 

“Kelp forests are one of the most important ecosystems on the B.C. coast,” says Martone. “If we understand how kelp is doing, then we have a better understanding of how the rest of the ecosystem is doing, too.”

In some places, huge beds of kelp are gone. In others, it is resilient or even thriving. Now the team is trying to disentangle all the variables to understand why. “Our primary suspect for change is warming ocean temperatures,” says Martone. 

It’s more complicated than blaming climate change, though. There’s the complicated ecological feedback loop between sea stars and sea otters. (The otters nurture kelp forests by eating the grazers, like urchins, that eat kelp. When otters decline, so does kelp). There’s also human development, climate change and the commercial harvest of other marine species. All these factors could affect kelp forests, says Martone. That’s why further research is needed.

Scientists know even less about kelp in Arctic waters, says Philippe Archambault, a marine ecologist and kelp researcher from Université Laval in Quebec City. The last kelp study in the Canadian Arctic took place in the 1970s and 1980s. In the meantime, Arctic sea ice has retreated, air and ocean temperatures have increased, and melting glaciers and thawing permafrost have made the ocean water cloudier. 

“Because the Arctic’s ocean conditions are changing so fast, it’s important for us to know the present to understand the future,” says Archambault. In 2019, he led an expedition to the Arctic as part of the ArcticKelp Canada project, a five-year effort to learn more about the region’s kelp — with scientists from 10 universities and Fisheries and Oceans Canada. They originally hypothesized that, because of ice cover and the short growing season, kelp wasn’t as important to the Arctic Ocean ecosystem as it was to the Atlantic and Pacific. “But every time we dove, we found kelp,” Archambault says. In the North, it tends to grow shorter and in shallower water, but the forests of shrubby greens and brown leaves still carpet the ocean floor, playing an important role in Arctic marine ecology.

ArcticKelp’s research mostly focused on creating a baseline of kelp distribution in the Arctic, but individual studies made some interesting discoveries. They found kelp growing far faster than they expected — and far richer biodiversity in the ocean floor around kelp beds than in areas devoid of the seaweed. An ongoing study is comparing growth rates of a species of kelp in the Arctic to the same species in the Gulf of St. Lawrence. COVID-19-related travel restrictions prevented a follow-up expedition in 2020, but the research has carried on with help from local Inuit, who continue to send observations south. 

An Indigenous connection is a common theme in almost all the kelp projects. It makes sense: kelp has always been a vital part of their diet and life. Now, in the Arctic, it adds a salty flavour to food and is an important source of vitamins and minerals, says Archambault. On the West Coast, First Nations used kelp for food, fishing lines, navigation and more. 

A vegan poke bowl containing Cascadia kelp, created by Chantal Davis of That Planted Life.(Photo courtesy Cascadia Seaweed)
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“One of our priorities is to restore the environment to its original state, so it can sustain our people like it used to,” says Larry Johnson, president of Nuu-chah-nulth Seafood, a firm owned by five Nuu-chah-nulth Nations on Vancouver Island’s west coast. “We also want to contribute to building the economy of our nations, so our young people can move back home and have a good job. Kelp farming can do both.”

It’s why Nuu-chah-nulth Seafood partnered with Cascadia Seafood on its first two farms. The three-year agreement allows the company to base its operations in Nuu-chah-nulth territory in exchange for employing and training Nation members, with an eye to operating its own kelp businesses one day.

Cascadia’s Bill Collins sees the Indigenous partnership as a key component of his company’s success. “They bring incredible knowledge about the area and the sea,” he says. “We bring the investment and [commercial] expertise. It’s a match made in heaven.”

They harvested the company’s first commercial crop at the end of winter 2021, and Cascadia launched its first food product, kelp jerky, this fall. They plan to expand the area Cascadia cultivates from 20 hectares today to 500 hectares by 2025. They’re already working with several other First Nations and coastal communities to make that happen and with chefs and food innovators to develop new kelp-focused products and recipes to build the market to support it. 

At the same time, Collins sees a future where research from MaPP and ArcticKelp projects, among others, will enable Indigenous groups in remote parts of the country to harvest and grow kelp sustainably, spurring economic development and jobs in areas with few other opportunities. Huge offshore farms will sequester carbon, and inshore ones will help clean up contaminated waters, including around more sustainable fish farms. Meanwhile, restoration efforts will re-establish kelp beds, improving biodiversity and resilience along the B.C. coast. 

The most exciting thing about kelp farming is that it’s not a choice between objectives. Johnson, whose Indigenous name is Anii-tsa-chist — which translates as “keeper of the sea” from a dialect of the Nuu-chah-nulth language — says kelp farming can do several things at once. Each farm would clean the water, sequester carbon, create wildlife habitat and provide employment and a sustainable future for his community, all without many of the negative impacts of other industrial activities.

“Teachings from our ancestors continue to remind us how we are connected to all beings, be they animals, plants, and/or supernatural. The Creator placed us where we belong, here, as stewards of our ḥahuułi, countless generations ago. Our sacred teaching, hišuk ma cawaak, tells us that we were created together and are equal with all other beings of the natural world.

Our people believe our role is to maintain the balance in the ecosystem, only using what we need so that the resources will be there for seven generations,” says Anii-tsa-chist. “I think kelp can help us do that — and help me live up to my name.”


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November/December 2021

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