Kelp Is the New Kale Favorite 



Jan 1 2019

STONY CREEK, Conn. — Last year we saw images of farmland underwater everywhere. And, according to the USDA statistics, median farm income earned by farm households was forecast to be in the red, i.e., underwater. Bren Smith’s operation started out underwater and will remain there for the foreseeable future, because he farms the sea.

Photos provided by Green Wave This schematic diagram shows the arrangement of lines, floats and anchors for a 3-D restorative ocean farm. The arrangement, designed by Bren Smith, is repeated in several rows 50 feet apart.

Smith grew up by the sea in Newfoundland and worked on fishing vessels before finishing high school. After witnessing the depletion of oceanic fish stocks, he shifted to what is called “restorative ocean farming” with a focus on oysters, mussels, clams and seaweeds.

After decades of working the sea and experimenting with restorative ocean farming. Smith founded Green Wave, a nonprofit organization, to combat overfishing, eutrophication of coastal waters, degradation of marine ecosystems, and climate change, as well as to provide jobs for local fishermen.

According to the National Ocean Service, eutrophication is the process in which excess nutrients like nitrogen and phosphorus — from sources like fertilizer runoff, septic system effluent, and atmospheric fallout from fossil-fuel burning — flow via waterways into estuaries and coastal waters, where the increased nutrient load causes harmful algal blooms, dead zones and fish kills.

For developing his system of “three-dimensional ocean farming,” Smith won the 2015 Fuller Challenge in honor of designer Buckminster Fuller. Last year, he published “Eat Like a Fish: My Adventures as a Fisherman Turned Restorative Ocean Farmer.”

Unlike land-based operations, Smith’s crops are nourished by water currents that bring land-derived nutrients to his site daily. Moreover, his stock are immobile, fixed in place, and graze on plankton, floating plants and animals that are whisked past the farm on marine currents. The water at his farm is changed twice daily by tidal action. He doesn’t use fertilizer, antibiotics or pesticides.

In short, he says his farm cleans the environment by removing nutrients — including carbon dioxide —thereby addressing climate change and eutrophication.

To make a living, “all you need is $20,000, twenty acres and a boat,” Smith said.

Photos provided by Green Wave A view from above the 3-D restorative ocean farm in the Thimble Islands, Connecticut. Buoys mark the locations of lines used to support the growing kelp and shellfish.

“Buying” the Farm

While most land-based farmers own real estate, ocean farmers do not. But, they can rent the opportunity to use property from municipalities, states or the federal government. Leasing open water sites differs from leasing land; while you may lease a volume of water and the substrate, your ephemeral neighbors will be sailing, motoring, water skiing and even fishing over your operation.

Finding a site to farm takes time. Like with all real estate, location is important and considerations such as water depth, substrate composition, currents, tides, salinity, nearby rivers, etc. have to be considered.

He offers assistance in learning to “3D” farm through Green Wave for those interested.

Once locations have been identified, permitting can be a major challenge. All levels of government must be considered when developing leases and the rules differ from place to place. State divisions of fisheries, shellfish commissions, and the Army Corps of Engineers all have an interest in an underwater farm.

Leases typically run around $50 per acre, Smith said.

Photos provided by Green Wave Pickled kelp stipes, left, and butter fashioned from kelp, center, are just a few of the many concoctions created by chefs from kelp.

The 3D Ocean Farm

As with most beginning operations, Smith said “start(ing) small is good advice.”

He suggests a 10-acre site (660 feet by 660 feet), using the 2-1/2-acre square inside that to set lines.

“A plot this size will take 2 to 5 days to set up,” Smith said.

The first year, he recommends setting one line with floats, anchors and drop lines (as illustrated in the schematic figure on this page). “This will give the farmer a chance to see the influence of the elements — wind, current, light, etc. — on the layout.”

“Once I really know this plot of water, I can scale up to 100 acres,” Smith said.

Photos provided by Green Wave Bren Smith seeds sugar kelp. To do this, juvenile kelp plants are attached to a string wound around the white PVC pipe. Then, they are transferred to a rope in the 3-D farm framework.

Seeding a Crop

“Sugar kelp is collected in the fall and when the water temperature in the nursery is raised, the kelp spawns,” Smith said.

Then the kelp is cultured with string around PVC pipe; the larval forms of kelp attach to the string. After they have grown to an eighth of an inch in length, they are transferred to a line at the site by pulling the line through the PVC and uncoiling the string around the line (as illustrated in the photo on this page).

Shellfish, oysters, mussels, clams and scallops can be purchased as juveniles from hatcheries and transferred to cages or porous plastic bags and taken to the site.


Before the water reaches 40 degrees Fahrenheit in early winter, the kelp just soaks up nutrients. Then, it grows with the accumulated nutrients, at temperatures below 40 degrees. When the water temperature reaches 45 degrees in the spring, the kelp just takes off, Smith said.

According to Smith, 1 acre can produce a quarter of a million shellfish and 10 tons of edible kelp.

“The first of three harvests begins in April with baby-leaf kelp, which sells for $22 per pound,” he said. “(At) the end of May, a second harvest is taken by clipping below the stipe (stem) of the kelp, so that it can regrow for another harvest.”

These kelp blades are larger and can be blanched and cut into noodles, and served like pasta. It can be frozen and sells for $8 per pound.

“Because kelp hates oxygen, handling it during processing is tricky,” Smith said.

In June, the third harvest of kelp sells for about 50 cents per pound and is used as organic fertilizer and animal feed.

Having collaborated with chefs, Smith will quickly point out there are any number of kelp-based dishes and drinks that have been concocted.

Kelp and shellfish have a “terroir,” or flavor and character, based on the location and conditions in which they are grown. Smith sees this as a marketing feature.

“Being in the lower reaches of the sugar kelp range, our product is more delicate than that grown further north,” he said.

Kelp also provides shelter and nutrients for a great variety of other organisms that Smith called “the serendipity harvest, such as ribbon kelp.”

“Mother Nature abhors monocultures,” he said.

Smith knows the 3D Ocean Farming system can be scaled up in size, but said he would prefer to see young farmers with little access to land take on the challenge, so they can produce wholesome food, clean the environment and mediate climate change.

In addition to harvesting edible products, farmers can earn income harvesting data, using sensors in their ocean farm and be paid by Green Wave for this information. The information provides data on how the system works, any ecosystem services provided, and its impact on climate change.

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How does this project help?


I think this project has been very effective because it has enacted long-term change in the climate change and fishing community. It has gained lots of media attention, as well as brought shift to the culture in terms of climate change and the way people think about their seafood consumption and alternative options to seafood and fishing.