In 1835, on a trip to the Galapagos Islands, Charles Darwin noticed giant kelp forests ringing each of the islands. “I can only compare these great aquatic forests with the terrestrial ones in the inter-tropical regions,” he wrote.
Darwin believed that these kelp forests fostered some of the most impactful ecosystems on earth. He was, in a way, entirely correct. Kelp forests sequester 20 times more carbon than land-based forests. And farmers, conservationists, and ecologists alike are taking notice.
The National Oceanic and Atmospheric Administration (NOAA) classifies kelp as a “foundational species” because kelp forests produce the conditions for hundreds of other species to live and thrive. Kelp attaches to submerged rocks in cold water areas where most aquatic plants can’t root down. The plants can grow up to 200 feet tall, shading the area so more invasive algae can’t grow. Kelp forests can flourish in areas with strong currents, and provide a habitat for fish and other marine animals that otherwise could not live in rough waters. Curbing the ocean currents also helps the shoreline; calmer currents mean less rapid erosion.
Almost a third of the world’s coastal environments rely on kelp — whether to absorb and reduce local pollution or sustain fish populations and ecosystems — according to a new study published in Nature. The entire world relies on kelp forests’s ability to sequester carbon from the atmosphere. But these kelp forests are vanishing. Sea temperature rise, overgrazing by fish and sea urchins, overfishing, and water pollution all threaten this vital organism.
The Kelp Forest Alliance, a non-profit organization that restores and protects kelp forests, estimates that their restored kelp forests have captured 486,080 tons of CO2 — the equivalent of 108,168 gasoline-powered passenger vehicles driven for one year or the same amount of carbon that 579,659 acres of US forests sequester in one year.
Kelp Farms
Beginning in the early 2000s, kelp farms began to pop up in the US. Maine, one of the earliest adopters, now boasts over 321 leased areas of ocean for growing kelp — with the state opening more each year — and produces hundreds of thousands of pounds of kelp yearly.
Farming kelp is a low-investment and low-risk process: Kelp can grow up to two feet per day, and require no pesticides, fertilizer, or freshwater to grow. Seedlings are attached to a line and submerged about 6-10 feet below the surface of the ocean and are all set to grow.
Farmed kelp is sold and processed mostly for pharmaceutical products, fertilizer, health products, beauty products, bioplastics, fuel, and food additives. Few farms sell kelp for regular consumption, though the health benefits of kelp are numerous. Kelp is a superfood that contains iodine, iron, calcium, folate, magnesium, vitamin K, healthy fats, and protein. But, because kelp can absorb so many water pollutants, farms for human consumption need to be in less industrialized areas.
Not all kelp farms need to be for commercial purposes. The Shinnecock Kelp Farmers in Southampton, NY are farming kelp to clean up the Shinnecock Bay. This Indigenous-owned and women-led nonprofit began using ancient practices in 2020 to counter the effects of climate change and restore and protect the waters of the Shinnecock Tribe. Kelp and other seaweeds act as sponges, absorbing heavy metals, nitrogen, phosphorous, and other pollutants in the water around them, making kelp an effective tool against pollution. Eventually, they hope to sustainably harvest and sell excess kelp as an eco-friendly fertilizer.
However, farming kelp is not the same as growing kelp forests. Deep sea kelp forests are attached to the bottom of the ocean and sustain marine life. Kelp farms, on the other hand, stand as supporting characters to kelp forests: they facilitate the growth of coastal marine ecosystems, keeping the water clean and providing some of the benefits of kelp forests
That’s where farmers (or, more accurately, aquaculturists) such as Amanda Swinimer of Dakini Tidal Wilds come into play. Swinimer wild harvests the seaweed off the coast of Vancouver Island in British Columbia; meaning, she cuts the tops off of kelp that are firmly rooted on the ocean floor and sells the harvested portions. It’s a best-of-both-worlds situation: kelp can continue to provide habitat for other organisms to thrive and clean the water, and the kelp can be harvested as a nutritional powerhouse.
Regulating Unknown Waters
As more and more aquaculturists look to harvest kelp and other seaweeds, they are finding themselves stuck in a land of unknowns. There are no federal regulations for growing seaweeds as there are for other plants.
Aquaculturists and activists alike are calling for more policies to govern and protect their vital waterways and marine ecosystems. The hope is to grow the industry without compromising ecological best practices.
In China, where aquaculture is a booming business, extensive breeding of two seaweed species has left them more vulnerable to climate change — much like the over-cultivation of some land crops. Further, because it is still a largely unstudied industry, pests and diseases are reducing China’s annual seaweed yield. Sometimes up to 25-30% of a year’s crop is lost.
But lawmakers and activists are on the job. The Coastal Seaweed Farm Act of 2023, introduced to Congress in March 2023, outlines a comprehensive plan to study the effects of aquaculture and sustainable Indigenous harvesting methods. If passed, the bill also requires write ups of research-backed legislative plans for aquaculture regulation. One year after plans are submitted, as per the bill, Congress must establish the Indigenous Seaweed Farming Fund to further the sustainable growth of aquaculture.
Governor Kathy Hochul signed legislation in 2021 to allow commercial kelp farming in two areas of Suffolk County, NY. In the press release for the legislation, Gov. Hochul said, “The cultivation of kelp and other seaweed will help restore the health of ecosystems in these bays, promote the emerging aquaculture market, and support the local economy.” We really hope so, Kathy.
Like Darwin said, after his 1835 trip to the Galapagos Islands: “If in any other country a forest was destroyed, I do not believe so many species of animals would perish as would here, from the destruction of kelp.”
