Susan Hand Shetterly | Excerpt adapted from Seaweed Chronicles: A World at the Water’s Edge | Algonquin Books | August 2017 | 16 minutes (4,260 words)

Occasionally you can still find them out on islands, crumbling near the water’s edge, the old eighteenth- and nineteenth-century kilns built out of stones gathered from the shore. People on the Irish and Scottish coasts and in Brittany cut and burned seaweeds in the pits of those kilns to make potash and pearl ash, valuable potassium salts. The wet seaweeds — AscophyllumFucus, and the kelps — had to be lugged up from the shore, carefully turned and dried, and then burned at a temperature that would render them into products that were sold to make glass and soap, to bleach linens, to encourage bread to rise, and to use as fertilizer to sweeten fields. In the boom time, around 1809, Ireland was exporting about 5,410 tons of potash a year. It was backbreaking work that whole neighborhoods engaged in, and at its height, the many kiln fires created smoke so thick it endangered the lives of nearby pasturing cows. It wasn’t long before the seaweeds in some places were overcut, the shores laid bare.

Then, as suddenly as it had appeared, the market vanished when potassium salt deposits were discovered underground in Germany and in Chile, and mines were opened.

The burning of seaweed resurfaced with the discovery that the ash residue could be used to extract iodine. But that, too, disappeared when deposits of iodine were found belowground. Left alone, seaweeds regrew, with farmers coming to the shore to harvest them for their gardens, and gatherers cutting favorite species to eat and to feed to their domestic animals. Over time, the old kilns were disassembled by wind and rain and snow.

A lazy bed is not for the lazy.

My great-grandfather was born in County Mayo, a land of blanket bogs and clay on the western shore of Ireland, facing the North Atlantic. He was just a boy when he sailed to America with his parents in the 1860s. Somehow, they had survived the famine.

Even today, you can see the ghost of the famine that provoked their flight and that of so many others in the ridges on the Mayo hills: old shapes of potato gardens, suddenly abandoned, as if time had stopped. And in a sense, it had. Either the villagers who cultivated the plots were too weak to dig into them anymore, or the digging would have unearthed only blight — or both — and they left them where they were.

Before the famine, the Irish farmers of Mayo and the Aran Islands and other sparse places near the coast, where the ground was poor and the rain was hard, had learned to fashion gardens that produced abundant, life-giving potatoes, enough to feed a growing family and the family cow. They called them lazy beds, and some farming coastal people in Ireland today have initiated the practice again. But a lazy bed is not for the lazy.

If you want to try one, here’s how to start: A farmer marks out the shape of a rectangular bed with twine across an open, mown field or a grassy yard, three feet wide, about ten feet long, with a further width of eighteen inches of uncultivated ground along each length. Then she collects seaweeds — kelps, knotted wracks, bladder wracks — that have been storm-tossed into windrows (not living seaweeds, but those that have become unmoored and are piled at the upper shore) and hoses them off to be sure they are salt-free, or she lets the rain gently cleanse them.

She spreads the seaweed generously over the grass within the rectangle at a depth of an inch or two and sets potato seed (chunks of quartered potato, cut and air dried, each of which contains at least one pale, fingerlike eye) into the seaweed that lies against the turf.

Then she takes up a sharp spade (in Ireland they call this a loy) and slices into one of the eighteen-inch borders of turf outside the twine, cutting away from the bed, carving a long strip of grass and root and soil, loosening it so that it is hinged only at the edge of the bed where the twine is. She lifts up the twine and folds that narrow strip over the bed, covering potatoes snugly beneath it. Over and over she cuts strips, turning them onto the bed as if she were turning the pages of a book, or folding sheets, working down one length of the rectangle, then up the other. Thus all the potatoes are covered, top and bottom, as they rest in a nest of seaweed. Only the upended grass roots and dirt show at the top of the bed now.

The twine is taken down, the eighteen-inch trenches are dug out, and the loose soil is mounded onto the bed as the potato plants sprout and grow. Underground, the grass and the seaweeds decompose, nourishing the potatoes, and the trenches on either side get deeper, supplying extra soil when needed and draining off excess rain, which is a problem in Ireland. The beds can be refreshed yearly with seaweed dug into them after the fall harvest.

On the Aran Islands, there is only an occasional thin skin of turf over bare rock to make a lazy bed. The old-time farmers would collect sand from the beach coves, mix it with decomposing seaweeds and what little there was of turf, and make their own soil, into which they set the potato seed, then shoveled more of the dirt and sand and seaweed mixture over the seed, building up the beds with channels for rain runoff on either side.

In his 1907 book The Aran Islands, J. M. Synge wrote this: “The other day the men of this house made a new field. There was a slight bank of earth under the wall of the yard, and another in the corner of the cabbage garden. The old man and his eldest son dug out the clay, with the care of men working in a gold-mine . . . for transport to a flat rock in a sheltered corner of their holding, where it was mixed with sand and seaweed and spread out in a layer upon the stone.” It may be a seaside farmer’s prejudice, but it’s claimed that nothing tastes quite so good as a potato grown in seaweed gathered from a nearby shore.


When I was a child, my family spent summers on Cape Cod, where my mother had worked in the theater before she married, and one of our pleasures was for my sister and me to walk the long sand beach hunting for clumps of Irish moss that had floated away from their holdfasts and arrived storm-tossed above the low-tide line. We were searching for the cream-colored, sun-bleached blades. After we had gathered enough, we brought them to our mother in the kitchen of the rented house and rinsed them over and over in cold water, both to dislodge sand and to rid them of some of that whiff of iodine and beach rot.

Then we soaked the clean, slick blades in warm water, tossed the water out, and set them in a pot with milk and lemon zest and a touch of vanilla. We put the pot on the stove, at a low heat, and watched as our mother stirred. The mixture began to thicken. Soon it was coating the spoon. My sister and I found this change magical.

Our mother cracked some eggs, beat the yolks with sugar in a bowl, and poured the thick seaweed mix through a strainer and into the yolks and sugar. She whipped the egg whites, folded them in, and served us custard.

Blancmange, she called it. It was a beautiful off-white linen color with just the slightest taste of the sea.

The huge facility contains a network of tanks filled with seawater and is in perpetual lockdown as if it were the Pentagon.

The Latin name for Irish moss is Chondrus crispus, and in Ireland the common name is carrageenan, an Irish word that means “place of the small rocks,” where, in the low and subtidal zones, it’s picked fresh. A species of red seaweed, it’s a beautiful purple color when growing. It looks a bit like the petals of a dark chrysanthemum.

The substance in Irish moss that thickened the blancmange is also called carrageenan. Science has appropriated the word to mean the emulsifier found in a number of species of red seaweeds. It is a phycocolloid (a seaweed gel), chemically inert, but with an adaptability that makes it ideal for combining ingredients into many products.

Three kinds of phycocolloids figure in the daily lives of people who live in the industrialized countries. They are used for thousands, perhaps millions, of processes. Some uses overlap between them, but in general, carrageenan (from the red seaweeds) is added to certain foods, such as some yogurts, soymilk, coconut milk, almond milk, some tofu, and cottage cheese, and toiletries such as shampoos, hair rinses, toothpastes, body creams — the list goes on.

Agar is another phycocolloid, also derived from red seaweeds and also used in foods. But it is, most famously, an invaluable suspension material for laboratory tissue cultures, a growth medium in petri dishes, and the gel used to separate strands of DNA.

Alginate, the third phycocolloid, is derived from brown seaweeds. It is an important ingredient in wound dressings (some wounds need to be kept moist and covered with a material that is nonabrasive), textile printing paste, coatings for high-end paper, and the fluids used in fracking.

Snowdrifts outside my house frame two photographs I’ve taped to the study window. They are of a woman up to her waist in water, walking in her seaweed garden in Bali, encased in a warmth I can only imagine. She wears a woven grass hat against the sun. The sky above her is broad and blue, and her seaweed garden grows on either side of her beyond loose stick fences, and it looks from here, from this season of snow and ice, as if life could go on forever just like this: one small bay and a family growing and harvesting seaweeds within it.

Today it occurs to me that she is growing Eucheuma, a tropical seaweed eaten in Indonesia and the Philippines and on many islands in the Indian Ocean and western Pacific. Eucheuma is also grown and harvested by local people to sell to international companies because high-grade carrageenan can be extracted from it.

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FMC, a company with a multinational reach, has at one time or another made everything from seaweed products to pesticides to amphibious landing vehicles. It is the only company in this country that produces food-grade carrageenan, and its seaweed-processing plant sits at the Rockland, Maine, waterfront, where it imports Eucheuma from the Pacific.

International trade creates some odd turns and twists: In our waters, Chondrus crispus, or Irish moss, grows abundantly, and it was once harvested and processed at this Rockland facility. But today, ships come in loaded with cargo containers packed with Eucheuma. Irish moss is rich in carrageenan, though not as rich as Eucheuma. The superior quality of the Pacific seaweed is why container ships tied up at the Rockland docks cast long shadows across the beds of Irish moss growing beneath them.

In November 2016, the National Organics Standards Board of the United States voted to remove carrageenan from use in organic food products. This sets in place a directive that, if it holds, will require all foods with organic certification to be free of any trace of carrageenan. The job will take time, but already some of the largest organic food manufacturers are adapting their ingredients.

The board chose to remove carrageenan from the organics list as a response to studies that have linked it to gastrointestinal inflammation, colon cancer in laboratory animals, and diabetes — an ominous list.

Dr. Andrew Weil, father of integrative medicine, suggests that as a result of these studies, carrageenan should be eliminated from one’s diet as a precaution, although he notes that both the United Nations and the World Health Organization have concluded from a number of countervailing studies that carrageenan can, in fact, be safely used in foods, including infant formula. But to make things more confusing, the European Union has decided to ban carrageenan from infant formula, although some studies suggest that carrageenan actually improves gut health. In Ireland, during the Great Potato Famine of the nineteenth century, Irish moss was an abundant food for starving people who lived by the shore. Very simply, it saved lives.

International companies that process carrageenan, such as FMC in Rockland, have stepped into the fight to keep their products relevant and profitable. It may be years before the public knows whether carrageenan is a helpful food additive or a big mistake. Data suggest that the carrageenan itself may not be the culprit; rather, the way the carrageenan is processed, or the contaminated waters in which it’s grown in some unregulated places in the world, may make it dangerous.

Charlesville, a seaside town on the southwest toe of Nova Scotia, Canada, faces into the Bay of Fundy. It is here on a large coastal site that Acadian Seaplants Limited has established one of its most spectacular and most secretive enterprises. The company is growing Chondrus crispus on land. The huge facility contains a network of tanks filled with seawater and is in perpetual lockdown as if it were the Pentagon. What it makes are not secret plans for war, however; rather, it replicates the life cycle and creates beautiful forms of the Irish moss originally gathered from coves and bays throughout the seaweed’s range. This assemblage of tanks, refreshed with water from the nearby ocean, and laboratories with the highest technology, speak to the ambition and range of this innovative Canadian company.

Tended within the facility by scientists who work to give it a rainbow of color morphs and what’s known as “mouth feel,” Chondrus crispus is meticulously prepared for the Asian market. It becomes a dazzling salad mix, or a blade slipped by a bartender into a dry martini, where it floats like a translucent flower. This is upscale designer seaweed, and so far, it has not been affected by the controversy in the United States and Europe.


Kathleen Drew-Baker never visited Japan, and yet her studies revolutionized the harvest and consumption of seaweed in that country.

She was born in England at the dawn of the twentieth century, attended the University of Manchester, and studied seaweeds along the northern coast of Wales, back when coal was king there.

In the days before the collapse of the coal industry, the Welsh mines employed whole towns. The miners walked to work carrying lunch pails and came home covered in coal dust. What moves me — always — in the old photographs are the smiles, the miners’ faces dark with the mine dust, their teeth white and their smiles real as they face the camera.

The northern coast of Wales is a wild area still, of cliffs and ledges, narrow roads, and shore paths from one village to another. The wind and surf are constant. Out over the water in their summer abundance fly gannets and cormorants, Arctic terns and Manx shearwaters, and from the cliff-side heathlands blooming in wildflowers rise the voices of stonechats, the thrush-like bird whose call is loud and sharp, like two stones tapped briskly together.

They were, in fact, two parts of the same organism.

Kathleen Drew-Baker came to this shore by train through mining towns, down from the gritty city of Manchester, and collected seaweed specimens to take back to her lab. A smart, dedicated woman, Kathleen became an accomplished field botanist and research scientist. She received the highest honors for her studies at the University of Manchester and was hired to teach. But she lived in a time when academic women, especially women in science, weren’t taken seriously if they chose to marry. When she married, she was let go from her job, and in the years before her reinstatement as an honorary research fellow, she worked out of a laboratory built for her by her husband. She also became the cofounder and first president of the British Phycological Society, a group of scientists interested in the study of algae.

Kathleen’s specific interest was in cryptogamic botany, the study of spore-producing organisms, which includes many species of seaweeds, and her specialty was the genus Porphyra, what we call laver and the Japanese call nori, the delicate, translucent red seaweeds found along a number of cold-water shores around the world, including those in Wales, the western North Atlantic, and Japan. (Only recently, Porphyra has undergone a reconfiguring and renaming by seaweed specialists, who have broken it into eight new genera, distinguishable only through DNA samples. I call it by the nomenclature that Kathleen used.)

In the Gulf of Maine, there’s a species of seaweed that’s easier to find than Porphyra at low tide. It’s called Mastocarpus stellatus, and we often see it in winter. It grows thickly up rocks in heavy surf in short, knobby orange-red rugs, and when the tide pulls back, it’s exposed. The common name for it is false Irish moss. Nearby these Mastocarpus beds, which are favored by overwintering purple sandpipers, appear strange splats of a hard, slippery, tar-like material. Most people — including, at one time, me — assume these stains come from boats, some sort of fouling petroleum residue. And we would be wrong.

Incredibly, the seaweed and the tar-like smears are different phases of the same organism. I mention false Irish moss in writing about Kathleen’s lifetime work because it’s easy to find along the shore, and easy to spot the two forms if you look for them.

What Kathleen revealed was much more difficult to discover. After years of work, she was able to write a scientific paper announcing that the species she studied, and a number of others in the genus Porphyra, also have phases that are radically distinct from one another and were therefore assumed to be unrelated.

Kathleen walked the Welsh coast, gathering and studying, and over time she connected Porphyra to the stubby, ribbonlike growths that were found on bits of seashells within the tides. This shell-inhabiting phase had been considered a separate genus named Conchocelis (after concha, the Latin word for seashell). In 1949, Kathleen published a paper in the journal Nature linking the two, describing the experiments she had conducted that led her to the conclusion that the thallus, or blade, was the haploid phase of Porphyra, and the other, the shell-inhabiting phase, was the diploid phase. They were, in fact, two parts of the same organism.

Her discoveries eventually had an enormous impact on seaweed farming in Japan, where at least two species of Porphyra, or nori, are harvested for wrapping sushi, covering rice balls, and seasoning soup. This beautiful and nutritious seaweed had been highly prized by the Japanese for over a thousand years, and long ago, peasants were allowed to pay their taxes to the emperor in nori — it was as valuable as cash.

Seaweed farmers in Japan traditionally ate fish and oysters from the bays as well as seaweeds, but harvesting Porphyra was a strange business for them because the seaweed utterly vanished in summer. They couldn’t find it anywhere. By early fall, nori farmers would set out hundreds of bamboo poles in local bays, and sometimes they would string nets from the poles, and — miraculously, as if the poles and the nets had summoned a reclusive nori god — minute germlings came, catching on the nets and poles, and then, as the weather cooled, a thallus or blade would begin to grow on them, very small at first, waving in the water, exposed and then covered by tides, delicate, veil-like soft purple plumes. The farmers would cut the blades a couple of times throughout the winter, carefully leaving unharmed the holdfasts, which are shaped like tiny buttons. As in our own gardens on land, where certain plants, such as chives and parsley, grow back if the roots and stalks are left, another crop of nori would emerge from the holdfast after the first was cut. But the seaweed was mysterious and the harvests were unreliable. Some years there were only a few blades to cut. Porphyra seemed to come and go without any way to predict it or to encourage it to stay. Farmers called it gambler’s grass.

Though members of the British Phycological Society immediately recognized the significance of Kathleen’s discovery as a brand-new piece of seaweed science, it wasn’t until much later that phycologists in Japan read her work and understood that she had solved the mystery that had bedeviled them for more than a thousand years: they needed a supply of shells to bolster the nori harvest.

Kathleen died young, in 1957, not knowing that her research along the wild Welsh coast would eventually transform lives in Japan, far away. Her paper had come out in the chaos after the war. Most of the fishermen and seaweed harvesters of Japan had left their work to become soldiers, and the oyster harvesting had fallen away during that time. That resulted in less shell debris in the bays, which meant fewer nori plants. But that wasn’t all: a series of typhoons had flooded the bays, washing fertilizers and pesticides into them from the rice fields. It was a period of hunger and disarray.

By the time the Japanese put Drew-Baker’s work to use, they had little nori left. Since then, the industry has grown so fast that it now mirrors the soybean fields and cornfields of Nebraska: miles of nori nets and poles stretch along the coastlines of Japan and also along bays in China. In many of these places, there are still prominent village cooperatives where neighbors work together, using sophisticated mechanization as well as hand labor for all aspects of the growing and harvesting of nori and the making of nori sheets, the most valuable seaweed product in the world for human food.

There is no marker that indicates Kathleen Drew-Baker walked the northern Welsh coast, but its raw beauty prevails, and you can walk it yourself and see pretty much what she did over eighty years ago. On a promontory along the coast of southern Japan, however, there sits a small shrine dedicated to Kathleen, where she is honored for her work every year.

Her son, Dr. John Rendle, visited Japan to see this shrine.

“My mother never knew what a difference her work would make,” he said. “She studied the seaweed for purely scientific purposes, but without her work the entire industry could have disappeared. I don’t know what my mother would make of it all now. She’d be surprised that what she did back then has now turned into a multibillion-dollar industry. But I don’t think she’d like sushi — she wasn’t very adventurous when it came to food.”

When she did her field research in Wales, at the height of the mining days, a miner’s breakfast consisted of a serving of cockles — the small, round clams dug from the sands at the shore — a rasher of bacon, and laver bread or a serving of laver cakes. Perhaps she never tried it. She might not have trusted it any more than she would have trusted sushi, but it has to be one of the heartiest breakfasts, once beloved by miners, and a part of cultural history throughout the country. Today not many people eat laver bread or laver cakes anymore, although there are traditional cooks who swear by them.

For those who have an adventuresome palate and access to a cold-water shore, here is how the Welsh make the bread and the cakes. But first, it’s important to note that in a coal miner’s house, the kitchen stove, fueled by coal, would burn all day long, heating the home and providing a place to cook. I mention this because laver requires a lot of cooking.

Laver, or Porphyra, grows where there are beds of empty shells of bivalves such as cockles, oysters, soft-shell clams, and mussels. Here on the Maine coast, the coves where laver predominates are mostly found along cobbled Downeast shores, where the tides pull away and the mussel beds and mussel detritus and the lavers are exposed together. Out of water, the seaweed looks like a pale purple scrunch of Saran wrap lying in the sun.

Laver should be gathered without disturbing the holdfast, then washed in multiple changes of water to dislodge sand and to rinse away some of the salt. Cooks set it in a pot at the back of the stove and simmer it for six hours with adequate water. It turns from a delicate purple to a bold dark green, and the blades disintegrate to a pudding-like consistency. Miners didn’t add a bit of lemon juice and olive oil before serving, but modern cooks recommend it.

It is spooned onto hot buttered toast and eaten.

Laver cakes are made by combining the pudding mixture, which can be purchased in glass jars in specialty stores, with oat flour and oatmeal to make a stiff dough that is pressed into patties, then fried in bacon fat. The cakes are served with bacon and a side of steamed or fried cockles.

* * *

Susan Hand Shetterly is the author of the essay collections Settled in the Wild and The New Year’s Owl, as well as several children’s books including Shelterwood, named an Outstanding Science Trade Book for Children by the Children’s Book Council. Shetterly has received a nonfiction writing grant from the National Endowment for the Arts and two grants from the Maine Arts Commission.  

Excerpted from Seaweed Chronicles by Susan Hand Shetterly. © 2018 by Susan Hand Shetterly. Reprinted by permission of Algonquin Books of Chapel Hill. All rights reserved.

Editor: Dana Snitzky