History
A Short History of Seaweed Around the World: Kelp Farming, Murky Monsters, Science, and Sustainable Aquaculture For the Future
Seaweed has a holdfast on coastal cultures. Here’s a bit of seaweed history to celebrate the end of summer.
Tangled, briny masses of kelp litter the shoreline, curling around your ankles as the waves crash onto the strand.
The baby uses a piece to adorn their sand castle, and you recline underneath under an oversized umbrella. What’s for lunch? You check nearby restaurants. We could go for some sushi right now. Or ice cream. Anything to take the edge off this simmering California sun.
But whether you’re spending your summer by the beach or in a landlocked (and hopefully air-conditioned) apartment, you likely consumed seaweed today. Algin, for example, is a key ingredient in toothpaste.
Seaweed is having a moment. It’s a food of the future. But kelp and seagrass were important long before seaweed salad hit the shelves at your local Whole Foods.
What even *is* seaweed?
Let’s start by clearing up one misconception: “seaweed” is the common name for many different marine plants and algae growing in rivers, lakes, and marine ecosystems. Large green, brown, and red algae make up three groups of kelp. They are not plants, but rather part of a different kingdom called protists.
Seagrasses
Seagrasses make up dense underwater meadows, which provide protected habitat and food for ocean animals. They are related to land grasses, palms, and flowering plants. Seagrass beds are some of the most productive ecosystems in the world.*
Kelp
Kelp also holds tight to the bottom of the sea floor or rocky reefs using a holdfast. Many species of large kelp also use gas-filled floats called pneumatocysts to help the algae’s blades reach sunlight cascading through the water.
All seaweeds use energy from the sun and nutrients in the water to grow. Some of the largest seaweeds, including Macrocystis pyrifera or giant kelp, can grow up to 2 feet (0.6 meters) per day. This fast-growing kelp can grow up to 175 feet (53 meters) and form thriving kelp forest environments.
A short history of seaweed farming
Historically, attitudes about seaweed varied depending on where you grew up in the premodern world.
According to Pérez-Lloréns et al., “In the Eastern world, they were very much valued, even revered, and included in the daily menus, as well as a means to pay taxes to the court of the Japanese emperor… In contrast, in most of the Western world, seaweeds did not enjoy the same elevated status. Their consumption was often synonymous with penury and frugality.” ¹
Seaweeds could be used to supplement diets with iodine and calcium. They could be used to fertilize fields or patch roofs. They could be used as fodder, fishing lines, buttons, and even mattress filling. But they could also be a sign of hard times, and harder yet to come.¹
In 701 AC, Japanese law stated that prized seaweeds Wakame and Nori could be used to pay taxes because these were favorite foods of the imperial court. Whatever was left over from royal feasts would eventually be sold on the open market. Seaweed made up for a lack of nutrients from fruits and vegetables that could be grown on the island of Japan. Kelp was grown on poles or long lines suspended in the ocean. Today, seaweed farming in Japan is a multibillion-dollar industry, and seaweed farmers in Japan are developing new varieties to withstand climate change.¹
On East China’s Jiaodong Peninsula, seaweed bungalows have stood for over 200 years, dating back to the Qin and Yuan Dynasties.
In South Korea, the island of Jeju is famous for the Haenyeo (or ‘women of the sea’) who collected seaweeds and mollusks from depths up to 10 meters by skin diving, much like the Japanese Ama. These women were forced into this role when Korean taxes forced their husbands to emigrate from Korea. These women were left to fend for themselves. Seaweed diving in Korea is considered a UNESCO Intangible Cultural Heritage of Humanity, and there are very few Haenyeo still surviving today.¹
Seaweed also became very important for starving Irish peasants during the Great Famine (1845–1852). Farmers would haul seaweeds from the coast to fertilize potatoes or supplement their diet with edible seaweed. In the novel Trinity written about this period, a main character Seamus described the strain his family endured to haul seaweeds onto shore: “If low tide came during the night, everyone worked by lantern light. When the shoreside harvest was completed and the sea calm, we’d go out… as part of sixteen-currach teams into the deeper water and cut loose an entire bed and drag it ashore like a waterlogged whale.” ¹
In Peru and Chile, seaweeds had been eaten since pre-Hispanic times. Conquistadores first prevented local communities from eating these seaweeds, but later adapted these harvests into their own diets.¹
In Hawaii, seaweed was part of a well-rounded diet. Additionally, Hawaiian women were prevented from eating fish and supplemented their diets with seaweed.¹
Meanwhile, the Gitga’at of Hartley Bay and surrounding territory on the north coast of British Columbia were the last group to harvest seaweed each season, and they made the most of it. “They wouldn’t spot-pick seaweed. The whole group would go out and clean out one place… And the next time they’d go for seaweed they would start at the place where they stopped the day before, or the tide before,” says Helen Clifton, one of the Gitga’at elders. But seaweed harvests are becoming less and less frequent in Gitga’at communities as the younger generation continues to buy store-bought foods.²
In Tanzania seaweed is the country’s third largest export, employing over 25,000 farmers, 80 percent of whom are women. Seaweed farming is also helping women improve their lives in Zanzibar. There, farmers are learning how to better design aquaculture sites, cater to markets, and process their crops. But these areas are also affected by a blight called ice-ice disease that is slowly ruining seaweed harvests as global temperatures increase. This disease makes sustainable aquaculture even more important for farmers, but it also drives up the price of producing seaweed in these African communities.
Kelp has incredible historical significance in coastal communities around the globe. What sort of stories, then, do these tangled seaweeds offer?
Seaweed folklore: gods and monsters of the deep
If seaweed collection and farming has been so important worldwide, then it follows that many myths underline the importance of this versatile algae.
Here are a few legends sampled from around the world…
Africa
Not many tales about seaweed come from Africa, but the water spirit Mami Wata brings good luck and healing to those who believe in her. If you get on her bad side, she can drown people who do not obey her wishes.
Asia
In Japanese folklore, a shōjō is a nature spirit with streaming red hair and a seaweed girdle. They spend their days drinking liquor by the sea and can determine whether or not you are good or bad at heart. The Minogame is another spirit that appears as a giant turtle covered in streaming seaweed. He represents longevity, but can just as easily poison wrongdoers. The Hōnengame is a similar female turtle spirit who can tell the future.¹
In Korea, old traditions say that a mother should be given seaweed soup after giving birth.¹
And in China, k’uh-lung dragons come from dazzling jewel eggs born of seaweed.¹
Australia and Oceana
In Australia, the Aboriginal people share accounts about Yawkyawks, creatures that resemble young mermaids with strings of seaweed or green algae for hair. They walk the earth at night or scout nearby coastal communities in the form of a dragonfly. Yawkyawks are fertility spirits, and just going near a Yawkyawk’s water hole can make a woman pregnant. They are a source of fresh drinking water for crops but cause storms when crossed.¹
In Maori culture, seaweed protected the god Maui after his mother abandoned him. In Hawaii, a ceremony called the aha hulahula occurs when members braid or bind a chord of coconut fibers with deep-sea seaweed. Only after this binding ceremony are the gods ‘bound’ to do the bidding of those who made the chord.¹
Europe
Greek myth abounds with seaweeds. One legend tells of the fisherman Glaucus, whose life changed the moment he ate the magical seaweed he’d used to bring previous catches back to life. On one hand, he became a god endowed with the gift of prophecy. On the other hand, he became part fish and has since spent the rest of his days underwater.¹
In the Celtic world, mermaids called merrows peered through seaweed hair. If their magical caps were stolen by fishermen, merrows might be persuaded to marry the thief in the hopes of discovering the cap’s hiding spot. There are also seaweed-dwelling fairy cows and a murderous shape-shifter man-horse in Celtic and Scottish folklore. But the most fearsome seaweed creature was the nuckelavee, a skinless one-eyed centaur that snorted poisonous vapor and started epidemics and droughts for no good reason. The only way to repel the creature? Fill the air with fumes of burning seaweed, of course.¹
In Nordic culture, an ominous Draugr or ghost with curling seaweed locks and sticky tentacles represented Vikings drowned at sea, sworn to protect the riches down below.¹
This post was inspired in part by the History and Folklore Podcast’s deep dive into European seaweed mythology, and a thorough analysis of seaweeds in mythology, folklore, poetry, and life. Learn more about European Seaweed lore here:
- https://historyandfolklorepodcast.libsyn.com/seaweed
- https://link.springer.com/article/10.1007/s10811-020-02133-0
North America
The Zuni of New Mexico believed that the being Awonawilgna created the universe and formed other gods from seaweed.¹
In the Pacific Northwest, Haida myth says that bull kelp marks the entrance to the house of a supernatural undersea chief. Kwakwaka used hollow, sonorous seaweed stipes half-buried under homes to project voices into the fireplace during ceremonies. This theater trick gave the impression that a disembodied voice had descended upon the room.¹
South America
In Huilliche culture in Chile, La Pincoya is a young woman who dances while covered in kelp. If she dances toward the ocean, that’s a good sign — the catch is going to be amazing that day. If she dances away from the ocean… today might not be the best day to head out to sea. Watch out! La Pincoya will try to seduce men and drag them into the sea, never to be seen again.¹
Seaweeds, just like the temperamental ocean in which they grow, are both a protector and a herald of storms. It’s not surprising that we fear both the gaping ocean before us and its flowing garlands of wild kelp. Naturally, the internet safeguards modern seaweed myths: man-eating seaweed, devils’ grottos, and unexplored recesses of our unexplored ocean.
Kelp and seagrasses might mark the entrance to mythological lairs, or they might hide something darker beneath impenetrable kelp forest habitats. As with all legends, what you believe changes depending on where you look.
How is seaweed used today?
Popularization of Seaweed
You’ve likely consumed seaweed today if you use fluoride toothpaste. Many everyday products use seaweed extracts like carrageenan, alginate, and agar for binding and building texture. Seaweed works behind the scenes, but it’s also been having a moment.
Part of seaweed’s rise to fame is a response to Americans becoming increasingly health conscious. Seaweed fills a lot of dietary needs for vegetarians and vegans, who tend not to consume enough iodine in traditional plant-based diets. Seaweed is also high in soluble and insoluble fiber. It’s also high in protein. Seaweed seems to be a perfect superfood.
And seaweed is versatile, too. It can be mixed into seaweed salad, incorporated into sushi, or dried and sold as ‘seaweed snacks.’ Seaweed can be part of your everyday routine, but it can also work its way into celebration and self-care. Seaweed infusions can be stirred into beer and beauty products.
All these new seaweed products seem healthy and environmentally sound. But do we have to worry about over-harvesting seaweed?
Kelp forests and seagrass in danger
Are kelp forests in danger? YES!! What part of our world isn’t in danger?
Sadly, kelp forests are under threat. Overfishing and disease have allowed seaweed-hungry prey like purple sea urchins to decimate kelp forests and create urchin barrens. Rising temperatures also threaten kelp forest survival.
Designating Kelp Forests as Marine Protected Areas is one step that can help save these vital habitats.
What’s new with seaweed?
Given the recent popularization of phycology, it’s not surprising how little we know about some areas of ocean biology. There’s a lot to explore.
For example, scientists only recently learned that seagrasses are pollinated both by the movement of ocean currents and tiny organisms like isopods living on and around these marine plants.
Researchers from the Monterey Bay Aquarium have used 140-year-old kelp pressings to study past ocean composition and ocean upwelling, the process by which nutrient-rich water comes up from the ocean depths.
They found that decreases in upwelling (and decreases in nutrients locked away in the seaweed pressings) happened at the same time as overfishing and the sardine fishery collapse in the 1950s that devastated Monterey’s Cannery Row. Solving this marine mystery can help scientists better understand and prevent fisheries’ collapse.
We’re learning how kelp forests are responding to invasive sargassum seaweed, and how seaweeds are going to respond to global climate change. But research is also helping us understand where and how kelp can help.
The University of Southern California has piloted a kelp elevator that can help optimize seaweed growth for use in biofuels. The solar-powered elevator moves giant kelp up into the sunlit shallows during the day and then retreats into the ocean depths at night so that the fast-growing seaweed can absorb nutrients at night.
While farming kelp alone will not solve our global climate crisis, there’s some hope that seaweed byproducts could help reduce US emissions. One type of red seaweed, when added to cattle fodder, helps to reduce methane emissions by 52–92 percent.
Sustainable seaweed farming could even replace corn additives, according to kelp farmer and environmentalist Bren Smith.
Check out How To Save a Planet’s Episodes on Seaweed Farming to learn how seaweed is gearing up to become a sustainable food of the future:
Seaweed is a sign of decadence, hardship, mysterious marine depths, and the future of climate change. Learning more about seaweed helps us better understand its global importance.
There’s so much more seaweed history than what I’ve listed here. Seaweed science is changing almost as fast as marine kelp grows underneath the waves. Share your seaweed knowledge below!
Works Cited
[1] Pérez-Lloréns, José Lucas, et al. “Seaweeds in Mythology, Folklore, Poetry, and Life.” Journal of Applied Phycology, vol. 32, no. 5, 2020, pp. 3157–82, https://doi.org/10.1007/s10811-020-02133-0.
[2] Pieroni, Andrea, and Lisa Price. Eating and Healing: Traditional Food As Medicine. CRC Press, 2006, https://doi.org/10.1201/9781482293616.
