Image of ocean farming from the website

Ocean farming: more food, less land, reduced GHG emissions

Dec 4, 2019 | Environment

By Gavin MacRae

The climate crisis will force a shift in where and how we get our calories. Farms in the future will need to produce more food on less land, all while cutting their greenhouse gas emissions.

For Bren Smith, director of the non-profit group Greenwave, this transition means expanding our definition of farming to include the ocean. Smith is the driving force behind the zero-input aquaculture system known as vertical or 3D ocean farming.

The 3D part may sound techy, but Smith says the concept is simple. A grid of ropes extend from anchors on the seafloor to buoys on the ocean surface. A horizontal rope scaffold is fixed off the vertical lines.

Supported by the horizontal ropes, seaweeds grow interspersed with cages for shellfish such as scallops and mussels. Oyster and clams grow in cages below on the seafloor. The resulting symbiosis produces high yields of diverse species on a small ocean footprint.

The farms are thriving ecosystems, Smith says, which create habitat for other marine life, offer coastal protection from storm surges, locally buffer against ocean acidification, and filter nitrogen from fertilizer runoff.

“Fresh water, fertilizer, feed, land, all those things, those inputs, the cost is going to go up in the climate era…. Zero-input food’s going to be the most affordable food on the planet. It’s going to move us to the centre of the plate.”

The cost of entry for 3D ocean farming is low relative to land-based agriculture (US$20-50,000 can bankroll a typical farm). Smith envisions 3D ocean farming as a vibrant new industry displacing extractive industrial fishing and creating jobs on small-scale ocean farms around the world.



In an earlier life, Smith’s livelihood as a commercial fisher ended with the collapse of the cod fishery in Newfoundland in the 1990s. After a stint at a Northern Canadian fish farm, Smith transitioned to oyster farming off the coast of New York.

Some years later, hurricanes Irene and Sandy left his oyster crop in ruin. At the same time, rising ocean acidification was killing oyster seeds, while warming waters drove lobsters further north. Determined to find a model of aquaculture more resilient to climate change, Smith teamed up with Charles Yarish, a seaweed expert from the University of Connecticut, to develop the 3D ocean farming system.

The result was so successful, Smith co-founded Greenwave to spread the word.

Greenwave’s training program has been inundated, Smith says. “Right now the demand’s too high. We have requests to start farms in 20 countries around the world. It’s just insane, we have a waiting list of 10,000 farmers.”

Despite Greenwave’s success, ocean farming hasn’t yet telegraphed to Vancouver Island – at least under the 3D banner.

But what Vancouver Island does have is a burgeoning interest in kelp farming.



“We’re in a region that has the richest kelp biodiversity in the world.” says Allison Byrne, a kelp researcher at North Island College’s Centre for Applied Research, Technology and Innovation in Campbell River. “We have lots of coastline and lots of capacity in small coastal communities in terms of marine and boating experience that could be applied to the industry. And beyond that there’s a lot of interest, specifically in kelp farming.”

At a seaweed commercialization workshop in Courtenay in June, Byrne says the room was “absolutely packed” with entrepreneurs as well as established fish and shellfish operations looking to diversify.

“There are a lot of companies and individuals that want to push this ahead and are working to do so,” says Byrne. “I think it will look a lot different five years from now, there’ll be a lot more startup farms.”

Another promising ocean farming concept called Integrated Multi-trophic Aquaculture (IMTA) was pioneered on Vancouver Island by Byrne’s former academic supervisor, eminent aquaculture researcher Stephen Cross.

In this arrangement, the waste from a fed species such as a fish or shrimp becomes inputs for other species such as shellfish or seaweeds. Though not yet pursued commercially on Vancouver Island, IMTA and 3D ocean farming share the goal of remediating ocean ecosystems and creating high yields on small footprints.

For ocean farming, and kelp farming in particular, to grow on Vancouver Island, seed and processing facilities are needed, says Byrne.

“We need to reach that critical mass of having enough biomass from multiple different growers to create a demand for processing facilities.”

“I would love to see young entrepreneurs and First Nation-owned businesses take on the industry,” says Byrne, “and I would love to see small and medium sized farms working together, at least at this point, to create a demand for processing.”



And while forward-thinking chefs have created a boutique culinary demand for seaweeds, there is plenty more market potential for kelp at the grocery store.

Kelp salad greens, chips, sauerkraut, pickles, smoothie cubes, tea, beer, gin, and more could be on the menu.

The largest food market, Smith says, is as a healthy additive to replace the soy ubiquitous in many foods.

Other opportunities for seaweed are for use as animal feed, fertilizers, and for high value compounds extracted for use in pharmaceuticals and cosmetics.

Byrne says the industry needs to continue educating the public on the environmental benefits and economic opportunities of seaweed agriculture. “I think it’s an unfamiliar sector, but once people learn about it, they love it,” she says.

“They’ve done such a good job marketing the concept in New England and on the east coast. But I think we can catch up in the grand scheme of things.”

Gavin MacRae is the assistant editor of The Watershed Sentinel, a publishing partner of Decafnation. Readers can reach him at








Bren Smith, GreenWave executive director and owner of Thimble Island Ocean Farm, pioneered the development of restorative 3D Ocean Farming. A lifelong commercial fisherman, he was named one of Rolling Stone magazine’s “25 People Shaping the Future” and featured in TIME magazine’s “Best Inventions of 2017”. He is the winner of the Buckminster Fuller Prize and been profiled by CNN, The New Yorker, Wall Street Journal, National Geographic and elsewhere. He is an Ashoka and Echoing Green Climate Fellow and author of Eat Like a Fish: My Adventures as a Fisherman Turned Restorative Ocean Farmer. 

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