Could seaweed be Washington's next cash crop?

With Washington's natural kelp beds declining, some scientists think seaweed aquaculture could fill an ecological niche and serve an emergent market. But the barriers to entry remain high.

Kelp on a beach

A bed of bull kelp off the shore of Owen’s Beach in Tacoma on Sept. 12, 2019. Washington’s kelp, especially in the Puget Sound, is seeing an alarming rate of loss. “Since 2013 the major stressor on kelp has been water temperature. We are seeing extremely high marine temperatures related to climate,” says marine ecologist Helen Berry of the Washington state Department of Natural Resources. (Dorothy Edwards/Crosscut)

Stroll along select Puget Sound shorelines at the right time, and you’ll see kelp and seaweed flirting with the waves. We mostly experience them as deep green seaweed blankets spread over rocks at low tide, or as underwater kelp forests of bobbing bulbs and stipes just offshore, each bursting with rays of mottled brown blades that are oily to the touch. But to our region’s marine ecosystem, these clumpy bits of vegetation mean everything.

Not quite plants, seaweeds and kelp (a subset of seaweed) are technically macroalgae — but they photosynthesize and cycle nutrients all the same. Our waters boast a huge diversity of these macroalgae, with at least 600 seaweed species (including 22 kelps) that provide food and shelter to fish and invertebrates. From floating green and red algaes to famous brown bull kelps fastened to the sea floor, they all create essential energy at the bottom of Puget Sound’s food chain.

Over the past few years, the state’s kelp forests have started disappearing, as ocean temperatures and levels of pollution and dissolved carbon have risen. But even as wild copses recede, a group of forward-thinking algae advocates is developing strategies to jumpstart a commercial kelp and seaweed industry in the region. In the process, they stand to help prospective farmers break into a $6 billion global industry and maybe even buffer some ecological damage from wild kelp loss. 

While global aquatic plant production has more than doubled since 1995, the practice of farming native species of seaweeds for profit doesn’t really exist in Washington yet. There are two hybrid commercial-research farms: an open-ocean one on Hood Head, coordinated by Puget Sound Restoration Fund Executive Director Betsy Peabody and oyster farmer and the fund's science adviser Joth Davis; and the other is at the National Oceanic and Atmospheric Administration's Manchester facility, where macroalgae researcher John Colt and ex-NOAA employee Diane Boratyn are investigating better ways to grow seaweed in land-based tanks.

“We know how to farm a lot of the species, but the market hasn't been there, or the conditions haven't been right [for decades],” says Teri King, a marine water quality specialist with Washington Sea Grant

But state- and national-level concerns about acidifying oceans that imperil both the shellfish industry and wild animals — in addition to burgeoning U.S.-wide curiosity about eating and using seaweed products — have brought a sharp increase in interest. 

“There was kind of a watershed moment when Betsy [Peabody] was interviewed by Lesley Stahl on CBS's 60 Minutes” about the Hood Head farm, says Meg Chadsey, an ocean acidification specialist with Washington Sea Grant. The piece championed seaweed aquaculture as a way to sustainably and lucratively both feed and cleanse the planet. “All of us were getting bombarded with calls and emails,” she says. 

Resources for seaweed farming are so sparse that this fall, Chadsey, Peabody, Davis, King and PSRF Deputy Director Jodie Toft secured just under $100,000 from the NOAA National Sea Grant to develop a start-up roadmap for prospective farmers in Washington. An additional $1.1 million went to WSG and more than 20 other groups to create a national seaweed farming resource hub. 

The statewide training program is “grassroots,” Chadsey says. “No one in Washington state said, ‘Please do this.’ … We all felt badly for not being able to respond [to questions about starting up a farm].” 

For the first workshop, streamed live Nov. 20 from Pacific Lutheran University in Tacoma, Chadsey says 275 people signed up, and more than 100 tuned in. A few dozen attended in person. 

“Now I think people are going to get serious,” says Dr. Thomas Mumford, who started experimenting with commercial seaweed aquaculture in Washington state in the ’70s and was a staff scientist at the Washington Department of Natural Resources for nearly 35 years. “Today was the first [time] in Washington I've sat down and had people say, here's how you grow it, here's what the markets are, here's the permitting issues, here's the food handlers — all these different pieces that you really need to think about. Most people don't put that picture together.”

But some seaweed aquaculture veterans think the road ahead could be long. A host of hurdles — from extensive permitting and licensing processes, to the difficulty in finding farm sites, to identifying markets for seaweed products — has historically slowed interest. 

Simply applying to start a farm without a guarantee can cost more than $30,000 — a steep ask for the new, small-scale farmers attracted to the prospects. In the open ocean, popular seaweeds like sugar kelp are seasonal products with short springtime harvest periods (others can be harvested in the summer), and the work happens in cold waters. Land-based operations can operate year-round, but securing a site is still an issue. And farmers still need to find customers. 

“If it were that easy, everyone would do it,” says Boratyn, who uses the crop from NOAA’s Manchester research facility for her seaweed-based skin-care line Sol-Sea. 

A growing seaweed market 

Successful seaweed farms have operated for years in Asia and Europe. China, Indonesia and Norway grow industrial-scale swaths of dulse, kombu, nori and more. In groups of farming rafts that together cover more than 10,000 acres (much larger than any U.S.-based operation), plants are wound along parallel lines of rope to float like loose scarves. Others waft underwater and get sucked up by vacuums

Washington tribal nations have harvested wild seaweed since time immemorial; many tribes place large cultural and religious importance with them, and manage wild crops as part of clam farms. Recently, biologists with tribal nations like Jamestown S’Klallam have expressed interest in seaweed cultivation to Washington Sea Grant, says King; and the Suquamish Tribe is part of the national Sea Grant seaweed farming hub initiative.

But outside of tribal nations and a presence in Asian grocery stores, seaweed as a staple or cash crop has seen traction in the United States only over the past decade. Species like sugar kelp (which can be used as a gelling agent in foods and cosmetics) have gained ground in California, Maine and especially Alaska, which already boasts at least 16 commercial seaweed farms. A lot of this growth has been helped by East Coast nonprofit GreenWave, which has trained more than 50 farmers across the country in “3D ocean farming”: farming shellfish and seaweed in the same vertical space underwater. 

The American appetite is catching up, too: Seaweeds are high in fiber, vitamins and vegetarian protein, and some think they may help regulate gut health

“I think that the suite of products that can be generated from seaweeds, that is one of the most exciting things,” Davis says. “The sky's the limit.” 

Seaweed is served wet for crunchy salads and ground into medicine. and its byproducts thicken ice creams and other creamy goods. They’re used in fertilizers and animal feedstocks, and there are even proposals to use seaweed as a source of alternative jet fuels.

In any form, they can be a lucrative crop. 

“We're looking at anywhere from $20 to $30 a pound wet-weight for some of the macroalgae” grown at the NOAA facility, says macroalgae researcher Colt. “Macroalgae is about 90% water, and [even] selling water at $8 a pound has a real economic advantage.”

Can the farms help fight climate change?

Many governments, research organizations and environmentally conscious consumers are most excited about seaweed aquaculture’s possible ecosystem benefits — especially when paired with shellfish farms. 

As carbon emissions warm the planet, most carbon winds up in the air — but approximately a quarter is swept up into ocean currents, where they concentrate to decrease the ocean’s pH in a process known as ocean acidification. Acidifying seas make it hard for juvenile shellfish to form shells, wrecking aquaculture industries and natural ecosystems. Add in the increasing temperature, pollution and excess nutrients that flow off land to create dangerous low-oxygen conditions, and they become inhospitable oceans. 

While many seaweeds like kelps grow best in cold water, they also do well in acidifying, nutrient-rich heavy — and their presence can actually help neutralize carbon and runoff. The World Aquaculture Alliance notes seaweeds vacuum excess nutrients out of their environment, and claims they are five times more productive than land plants at siphoning carbon through photosynthesis. This past October, the U.S. Senate hosted a hearing on federal support for expanded aquaculture in which researchers touted its low-impact nature and water quality benefits. 

In Washington, a key recommendation from the 2012 Blue Ribbon Panel on Ocean Acidification was for the state to invest in seaweed aquaculture research to explore whether the industry could measurably improve water conditions locally and create a “halo effect” for struggling species nearby. 

Those ecosystem functions are in high demand as wild kelp beds disappear from places like the South Sound. 

The Puget Sound Restoration Fund's Peabody and oyster farmer and scientist Davis are engaged in a five-year study at Davis’ Hood Head farm to measure farmed sugar kelp's impact on water quality. An official report is due later this year. 

"The project team is still finalizing results, but the model developed for the project shows that under the right current conditions and at the right location and density, seaweed farming could affect seawater locally, particularly when co-cultured with shellfish," Peabody says. "Detecting the kelp effect at Hood Head was challenging due to high current flow, though kelp grown at the site clearly assimilated carbon and nitrogen during grow-out."

Entrepreneur Jared Collingwood is in the midst of permitting and licensing start a commercial seaweed farm in Puget Sound. He started the process in July, but doesn’t expect permits until at least spring of 2020. 

“I have always wanted to be involved in environmental action, specifically conservation,” he says via email. “Kelp farming would allow me to help the planet and help people in relation to food scarcity and affordable sustainable food sources.” He hopes to market to health-conscious consumers who want to lower their environmental impact through their purchases. 

Rough seas ahead for seaweed farmers

Despite the surging market and growing interest, most experts think it will take years for seaweed aquaculture in Washington to pay off.

“There’s the impression that it’s working in Maine,” Chadsey says, “until you talk to the Maine Sea Grant staff who are like, 'Boy, is this hard.' ”

Throughout the workshop, Chadsey and others explained that farms — even those with research grants and government support — don’t start or operate without that difficulty, and the path to success isn’t straightforward. The same hurdles that have always been there remain. 

“I don't want to burst bubbles at all,” Chadsey adds. “I think seaweed aquaculture really has the potential to be great for our region, and I think it will happen just like it's happening elsewhere, but I think not everybody is going to be able to enter this area, and probably most of them won’t want to once they understand what’s involved.” 

It took Peabody and Davis about a year to get the permits they needed for their research farm, and they spent about $50,000 in permit costs. Davis already had a shellfish permit, Department of Natural Resources lease and shoreline permit in the same location. "We were not starting from ground zero," Peabody says. 

Chadsey says Laura Hoberecht, former NOAA West Coast aquaculture coordinator, told her seaweed permitting would follow a similar process as shellfish, which requires coordinating with at least nine local, state, tribal, and federal agencies.

Boratyn has been growing seaweed for her skin-care company for nearly two decades, and she still runs into hurdles. Despite using land-based tanks, which allow researchers to optimize growing conditions, her plants are vulnerable to temperature variation from climate change and any number of damaging organisms such as epiphytes that latch onto plants. 

“I love what I do, [but] climate change has brought about some challenges,” she says. “We've been working the last couple of years at mitigating and minimizing those things. … Puget Sound as a whole is rich, [but] there have been drastic changes. 

“The point is, no matter how much science you put in it, you’re still a farmer and people need to understand that,” she says. “You kind of have to be one with your plants.”

Update: Language was changed at 9:45 a.m. on Dec. 4, 2019, to better reflect how ocean acidification occurs.  

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