Can kelp farming help save our marine environment? - Salish Current
October 7, 2022
Can kelp farming help save our marine environment?
Richard Arlin Walker

On the waterfront at Guemes Channel, Teresa DelaRosa (at right) and fellow proponents including Jaime Diamond (at left) and William McWatters envision the many potential benefits of farming kelp on Guemes Island. They say the new industry would create local jobs and enhance marine health and agricultural soils. (Richard Walker photo © 2022)

October 7, 2022
Can kelp farming help save our marine environment?
Richard Arlin Walker


Teresa DelaRosa has long known the wonders of kelp.

The nutrient-rich seaweed with leaf-life blades bobs on the water’s surface off the shores of Guemes Island, where she lives. She eats kelp pickled, in salads and with rice. Customers shopping at the Anacortes grocery store from which she recently retired buy it in various forms, from paper-thin nori snacks to sushi from the deli.

Others may use kelp and not know it unless they read the ingredients label: kelp is found in products ranging from toothpaste and shampoos to dairy products and baked goods.

Now, concerned about human contributions to climate change, DelaRosa sees kelp’s benefits beyond gustatory goodness. She is a founder of SEA2SEED, an organization that is studying the feasibility of establishing a kelp farm off the shores of Guemes Island. Kelp would be made available as a fertilizer for Skagit Valley’s 89,000 acres of farmland. Kelp would replace chemical fertilizers that are a source of tainted runoff that makes its way into salmon streams.

The vision

A kelp farm on the small rural island, population of about 700, would provide on-island job opportunities for residents, most of whom commute daily via ferry to Anacortes, she says.

Proponents of a kelp farm on Guemes Island say farmed kelp would bolster marine health by capturing carbon and, as a fertilizer, improve the health of agricultural soils. (Image: Google/Maxar/USGS)

Kelp would be grown on long lines near the water’s surface, where it would absorb carbon dioxide that makes it from the atmosphere into the sea. Scientists say an increasing amount of carbon dioxide from vehicle and industrial emissions is altering the sea’s pH level. Carbon dioxide and seawater mix to create carbonic acid, which makes ocean water corrosive, particularly to shellfish and corals. Fast-growing kelp would sop up that pollution.

“Kelp absorbs carbon and if it’s used as a fertilizer for farms, a lot of that carbon stays in the soil,” said Jon Petrich, a SEA2SEED cofounder and member of the Anacortes Port Commission. “It can be a sustainable product for agriculture, but right now there is no local source for it.”

DelaRosa and Petrich are optimistic they can have a kelp farm in operation within 12 months. But they have to navigate a series of hurdles to get there.

A new industry

SEA2SEED is one of about 10 organizations interested in establishing kelp farms in coastal Washington. Kelp farming would be a new industry in Washington and the state is trying to streamline a permitting process and resolve some unknowns.

A proposed kelp farm would operate above state-owned aquatic lands; that would require a lease from state Department of Natural Resources, according to DNR’s Joe Smillie.

Thirteen Washington counties ring the Salish Sea; a kelp farm would have to meet the requirements of each county’s shoreline master plans, which regulate shoreline uses. Tribal governments would likely want to review applications to ensure a kelp farm wouldn’t interfere with tribal fishing in their usual and accustomed areas.

The U.S. Army Corps of Engineers would likely need to review applications to ensure a kelp farm wouldn’t interfere with navigation.

Kelp is considered a crop, so farming kelp would require a permit from the state Department of  Agriculture.

“We are identifying all the permits that would be relevant, and some of the regulatory agencies just don’t have that [identified] yet,” Smillie said. “It’s a fairly new industry here and it’s not something we can pull off the shelf and say, ‘Here, fill out this form’. We want to put together a streamlined process that is user-friendly and easy to navigate.”  

Another concern for the state: ensuring gear is properly maintained to prevent derelict gear from fouling the waters.

“We want to make sure any farms we lease or line up are thoughtful and sustainable and minimize any environmental impact,” Smillie said.

Optimism, potential — and reason for caution 

While kelp farming is a potentially new industry in Washington state, it is an established economic force in Alaska, Oregon, California and Maine, and elsewhere in the world. The 10 leading seaweed harvesters in the world — based in Nova Scotia, the U.S., Ireland, China, Scotland and India — harvest seaweed for use as biofuels and fertilizers and in foods, medicines and personal care products. 

Ten organizations are actively interested in farming kelp — such as this yellow kelp on a Seattle beach — around the Salish Sea, citing benefits for the local economy as well as benefits for sea health and agriculture. (Image: brewbooks / Creative Commons)

According to The Safe Seaweed Coalition, current seaweed food production is valued at $9 billion annually. “In the 10 years to 2015, the annual value of the seaweed market doubled in size,” the coalition reported. “Our oceans have the potential to produce 15 times more seaweed by 2050. This growth could provide employment for 150 million people around the world.”

Dense areas of kelp are known as kelp forests; they provide habitat for rockfish and numerous additional species including forage fish, invertebrates and salmon. Kelp also “absorbs vitamins, minerals, proteins and enzymes from seawater as it grows, which it converts into a form that the human body can digest,” per health and fitness writer Katie Lambert. “It is rich in antioxidants, like vitamins A and E, and essential minerals like iron and calcium.”

Popular types of kelp consumed as food are bull kelp and sugar kelp. (SEA2SEED’s proponents plan to grow and harvest kelp for fertilizer, not for food.)

However, a study funded by Western Washington University and the SeaDoc Society found that kelp can absorb chemicals that may be harmful to humans and recommends a determination of seaweed consumption rates.

The study measured contaminant concentrations in edible seaweeds from 43 locations in the Salish Sea, among them Port Angeles, Camano Head, Eastsound, Fidalgo Bay, Squaxin Island and Vashon Island.

Cancer-risk levels for polychlorinated biphenyls (PCBs) were exceeded in samples from 30 sites, and risk levels for benzopyrene — emitted in wood smoke — were exceeded in samples from two sites. Lead exceeded international limits at three sites, and cadmium concentrations exceeded international limits at all sites.

The report says seaweed consumption rates should be determined and guidelines developed for the harvest of kelp and locating of kelp farms.

“What we don’t want to get lost is how good seaweed is for you,” said Jennifer Hahn, principal investigator and a research associate at WWU’s Fairhaven College. “But at the same time, we need to be able to show anyone looking to harvest seaweed where they can do it most safely, and how much of it they should eat.”

Benefits from farm to sea

One kelp farm applicant, Blue Dot Seafarms on northern Hood Canal, participated in a pilot project with DNR, growing and harvesting kelp for use as a fertilizer at a Whidbey Island farm

SEA2SEED sees the potential of kelp farming to improve the health of the environment from farm to stream to sea.

“As a carbon sink, it’s huge,” said Katrina MacIver, a SEA2SEED board member, marine biologist and research assistant with Pacific Mammal Research in Anacortes. “Ocean warming and ocean acidification are happening predominantly because of climate change and the carbon dioxide that gets dissolved into the water, so if there are resources like kelp farms that can actually help to mitigate those impacts, it’s going to be huge, especially in our area.”

Recent analyses show a decline of more than 90% in bull kelp in south and central Puget Sound in the last 150 years, along with similarly disturbing trends among other kelp and eelgrass species, according to DNR.

Other areas of the Salish Sea are reporting declines in bull kelp populations. According to a 2018 report published by Vancouver Island University, bull kelp populations have been in steady decline within the central Strait of Georgia for about 30 years. In some areas, coastal Vancouver Island residents have reported bull kelp nonexistent in regions where it was previously abundant. 

“Reasons for significant declines of [bull kelp] forests in the Salish Sea may include coastal development, rising ocean temperatures, local changes in oceanographic conditions (e.g. salinity, turbidity and sedimentation), intensified herbivore grazing or a combination of these factors,” the university reported.

Sen. Liz Lovelett (D-Anacortes) calls kelp and eelgrass “a crucial resource” in the fight against climate change. She authored SB 5619, signed into law March 30, which intends to conserve or restore 10,000 acres of kelp forests in Washington’s waters by 2040.

“It’s no secret that Washington is home to the most beautiful natural environment in the country, but our ecosystems are facing an existential crisis at every level,” she said. 

In addition to Lovelett’s legislation, several federal and state agencies, tribal governments and marine conservation nonprofits published the Puget Sound Kelp Conservation and Recovery Plan in May 2020 to coordinate response to bull kelp declines throughout the Puget Sound region. 

On Guemes Island, SEA2SEED’s Petrich and DelaRosa see kelp farming as another tool to help improve the health of land and sea and create jobs. 

“We love the idea of bringing a stable, year-round industry to Skagit County, but the commercial side is not what we’re passionate about,” Petrich said. 

“It’s not about getting rich,” DelaRosa added. “It’s about helping people and helping the planet.”

— Reported by Richard Arlin Walker

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