Kelp Is Not the New Kale; It’s a Crop With Bigger Challenges, and Possibilities

Since the coronavirus pandemic began, people all over the country have been getting food delivered to them in new ways — from farms dropping produce shares on stoops to fine dining restaurants making contactless deliveries of groceries and prepared foods.

But in Portland, Maine at the end of April, residents opened their front doors to find boxes of fresh, local kelp. “Everyone gets excited about ramps, but kelp is really the first crop here,” said Josh Rogers, a local seaweed evangelist who owns the shop Heritage Seaweed and has his own line of seaweed teas, Cup of Sea.

Rogers is also behind Portland’s Seaweed Week, an annual kelp harvest festival that was set to include nearly 100 participating restaurants this year, including the popular, now national chain, Luke’s Lobster. COVID-19 stymied the celebration, but the kelp-to-quarantine boxes were a surprising success.

For several years, environmentalists and aquaculture advocates have been pushing Americans to eat more seaweed, touting it as a flavor and nutrition-packed food that as a crop, has an incredibly low environmental footprint and could even help mitigate climate change. The efforts led to substantial media coverage declaring “kelp as the new kale,” but actual adoption into the American diet has moved at a snail’s pace.

Still, while growing the market and building processing infrastructure has proved challenging, in the US, more farmers are growing kelp than ever before. National statistics are hard to come by, but Maine is the epicenter, with 30-40 farms operating about 200 sites. From there, a coastal kelp belt extends down through New England as far south as New York. Seaweed farms are just starting up on the West Coast, and the largest in the country was recently established in Alaska.

And kelp’s possibilities to impact the food system extend beyond the dinner plate. It is already being used as a fertilizer and to make biodegradable food service items like compostable straws — and it has potential as a sustainable ingredient in animal and fish feed.

Nearly everyone in food production agrees that given the scarcity and degradation of arable land, the ocean will play an important role in producing food for a growing population. But most businesses focus on seafood people already buy a lot of, like salmon. Smith, who also wrote “Eat Like a Fish”, says the key is to think in the opposite direction. “For farmers, there’s a bit of a reality check about what the oceans can and will provide. You ask the ocean what to grow, and the ocean’s like, ‘Why don’t you grow things that don’t swim away and you don’t have to feed?”

That line of questioning leads directly to seaweed (and shellfish). Kelp, in particular, is native to and thrives in New England’s cool waters. A farmer places moorings and hangs thick ropes not far below the surface of the water. Seedlings on a thin string are attached to the ropes and blades grow downward, reaching towards the bottom. The crop grows quickly, maturing from seed to harvest size in about six months, and requires almost zero maintenance in between. Farmers simply motor out and check on their lines regularly.

“You can get a return on your investment the same year that you put it in the water, which is pretty unique” compared to shellfish like oysters and clams, said Jaclyn Robidoux, who focuses on development of seaweed farming as a member of the University of New England’s Marine Extension team. Plus, many kelp farmers starting out in Maine already have a boat or know someone they can borrow gear from, she said. “Maine is a really small place, so maybe you know someone who’s able to pour the concrete and set up your mooring,” she said. No matter what, in terms of agricultural endeavors, the start-up cost for a small farmer is relatively low.

“That’s why I end up on kelp. Not because I like kelp,” Smith said. “I end up on kelp because the economics of it really work at the farm level.” And, of course, because of its climate promises.

Kelp’s Nearly Non-Existent Foodprint

As Smith hinted at, all of the big environmental issues associated with farming fish in the ocean are a moot point when it comes to kelp. It can’t swim away and disrupt wild fish populations, it doesn’t produce waste, and it doesn’t require any feed or fertilizer. Compared to land-based crops, it also doesn’t require water. Zero inputs means the only real emissions involved are in boating out to tend to the crop.

In addition, kelp crops can actually provide ecological benefits in the face of a climate crisis. The ocean absorbs excess carbon dioxide from the atmosphere, causing acidification, which threatens the survival of coral, shellfish, and the entire marine food web. Kelp can absorb carbon, helping to combat acidification. Research is ongoing to quantify that benefit, and Robidoux said more is needed to determine at what scale kelp farming could have a real impact on mitigating climate change.

Smith is also an advocate of growing kelp alongside oysters, mussels, and clams in a diversified system he calls “regenerative ocean farming,” similar to how regenerative agriculture on land goes beyond the “do less harm” ethos to provide environmental benefits. Shellfish like oysters are also zero-input crops and provide ecosystem services like creating habitat for other creatures and filtering excess nitrogen and phosphorus.

When GreenWave helps set up farms, it determines what the farmer should grow based on the landscape. “Every patch of water is different as you move around. The key to the system is that it’s the same physical structure,” Smith said. “You build the same scaffolding; it’s very modular in that way. It’s just about picking the right species and appropriate model for each region and person.”

The Market for Kelp

Greenwave has trained 120 farmers in regenerative ocean farming so far and plans to train another 250 this year. It hosts webinars and builds online toolkits for would-be farmers. It hosts regional trainings in New York, California, and Alaska. The goal is to train 10,000 regenerative ocean farmers in 10 years.

So, where will all that kelp go?

Despite the slow growth in American consumption, Smith said kelp has made serious in-roads into the restaurant world (which is a challenge right now, with restaurants shut down) and points to examples like Sweetgreen’s recent high-profile kelp salad.

Rogers said business at his shop has been growing year over year and that interest in Seaweed Week has exploded. Portland residents who ordered the fresh kelp deliveries used it in recipes like pesto, compound butter, and lasagna at home. And Robidoux said many Maine businesses had done a great job at incorporating kelp into products eaters are already familiar with, like Atlantic Sea Farms’ kelp kimchi. “Those kinds of products are like the gateway to trying seaweed,” she said.

However, instead of thinking about kelp as the “new kale,” Smith suggests, a more helpful metaphor is envisioning the “soy of the sea,” produced in an environmentally beneficial, not extractive way. Like soy, kelp is a crop that can be processed into a wide variety of foods — and beyond. He is already selling kelp for use in bioplastics, to be made into biodegradable straws. Because kelp is rich in nutrients like nitrogen and phosphorus, GreenWave is also excited about selling it as a fertilizer for farmers, to supplement their land-based sustainable practices. “There’s huge potential to bridge nutrient cycles…and break down the wall between land and sea,” he said. Finally, kelp farmers may be able to harvest ecological data, be paid for carbon and nitrogen offsets, and sell their crops for biofuel as that market develops. Some companies are also already using a different variety of seaweed, ascophyllum nodosum, which is often referred to as kelp, to make supplements for animal feed. At the moment, it’s primarily wild-harvested rather than farmed. Many people see potential, however, for farmed kelp to play a bigger role in the development of more sustainable feed for farmed livestock and fish in the future.

The biggest challenge to moving all of this forward is a lack of processing infrastructure to get kelp from farm to customer, whether that customer is a farmer in need of fertilizer to add to a compost pile or a home cook eager to make broth with dried kelp.

And with the ocean rapidly warming and acidifying, time is of the essence.”Shifting tastes are slow, and they might be too slow for climate change,” Smith said. “Just because we can get it to work, doesn’t mean we’ll get it to work.”