The Learned Pig

Art – Thinking – Nature – Writing

Macroalgae Matters

Storm, my large black-and-white dog of indeterminate breeding, doesn’t let me miss too many weekend afternoons at the beach. So here we are, threading our way through the dune of sea oats, railroad vine, morning glory and sunflower to reach the shoreline. But something’s different this spring day, my nose tells me before I even glimpse the ocean. A rotten-egg funk outmuscles the more pleasant dusty green smells of the dune and saline of the Atlantic. I see where the aroma must come from as soon as we clear the dune, flashing my dog-permit to the park ranger in her all-terrain vehicle. The sand just above the tideline is frosted with an especially thick and wide layer of seaweed that looks like sargassum. The yellowish brown matt stretches south and north along the sand as far as my eyes can see. The water’s calm surface, too, is corrugated with sargassum thickets and stained the color of a murky tea.

Storm sprints down to the weeds and tears figure-eights across the vegetation in its state of fragrant decay, energized by the novelty. I find, however, that it’s not so easy to lumber atop the seaweed once I catch up to him. Glancing down, the fronds of this particular sargassum seem less leafy than the sargassum I know, mostly a tangle of filaments and tiny air bladders. Now I’m used to seeing and smelling seaweed at my local beach. I’m used to feeling okay about it that the park service doesn’t “clean” it from the sand, knowing that the sargassum on shore and in the open ocean provides nourishment and protective cover for various creatures, including our embattled sea turtles. Yet the sheer quantity of this stinky stuff lathered over the sand and lolling in the current is of a different order entirely; it can’t be so easily written off as “natural.” Plus, flies of some sort loop whirligig about my calves and turns out they bite.

It all seems, in a word, wrong.

While I’m probably more receptive to outdoors phenomena than most, the truth of the matter is that I’ve never really given much thought to seaweed. My line of sight in this swatch of south Florida I’ve called home for nearly twenty-five years has ever tilted above the drifting seaweeds toward the ospreys, terns, and frigatebirds above, or below the skin of the sea toward the snapper and snook. Only after sargassum starts to make such a nuisance of itself on my local beach do I truly begin to see it and think about it in earnest. For it shows no sign of abating as the season progresses and the days grow longer and hotter. A rare west wind blessedly pushes the seaweed offshore, but on most days nets of the scratchy stuff permeate every liquid ounce in the ocean shallows rendering it virtually impossible to swim. Many of my neighbors, friends I’m used to seeing at the beach regularly with their dogs, stop coming altogether.

Suddenly, I’ve got sargassum on my mind.

Sargassum, I learn, is a brown macroalgae with over 100 species worldwide. Certain species of sargassum, including the two common to my local waters, natans and fluitans, represent the only seaweeds that don’t at least begin their life attached to the ocean floor. Partly on account of their free-floating ways, we’re in the midst of the largest sargassum bloom in the world, beaches from Mexico to northern Florida buried under this “algal explosion,” as one source puts it, extending some 5,500 miles between West Africa and the Gulf of Mexico and comprised of over 20 million tons of biomass. Scientists suspect multiple human-born causes for the epic bloom, including deforestation and increased use of chemical fertilizer in Brazil, and smoke and dust from massive African fires—many started intentionally to clear land—falling into the ocean and providing additional nutrients to the seaweed. “The ocean’s chemistry must have changed in order for the blooms to get so out of hand,” one marine scientist puts it, having led a study of the phenomenon recently published in Science.

Marine algae account for half the oxygen in the earth’s atmosphere… hundreds of organisms rely upon seaweed for food, cover, and reproductive habitat.

While certain species might benefit from the Great Atlantic Sargassum Belt, as it’s now called, scientists worry about its more prevalent, deleterious effects on the environment. The expansive matts in the shallows block light from reaching already stressed corals, seagrasses and other organisms, they accumulate heavy metals such as cadmium and arsenic, which may be a source of ground contamination, they may cause elevated levels of the bacteria enterococci in beach waters, associated with gastrointestinal diseases and skin rashes, and they hold jellyfish larvae and other organisms that sting swimmers and leave terrific rashes (I speak from experience on this front). The thick blankets of seaweed on shore produce that hydrogen sulfide gas I smelled, a mere irritant for most people but particularly harmful for those suffering from asthma or other respiratory illnesses, and they may interfere with sea turtle nesting activities and hatchling survival rates.

I continue to read up not only on sargassum but on its seaweed associates. I buy and devour in one sitting Susan Hand Shetterly’s excellent Seaweed Chronicles: A World at the Water’s Edge (2018), which, in turn, leads me to an earlier classic by Rachel Carson, The Edge of the Sea (1955). I learn some astonishing facts. That marine algae account for half the oxygen in the earth’s atmosphere. That hundreds of organisms across the food web (from isopods and amphipods to fish and birds) rely upon seaweed for food, cover, and reproductive habitat. That Carson called the intertidal zone of seaweeds in Maine an “underwater forest.” That most of us consume or otherwise encounter seaweeds during the course of our day, even though we probably don’t know it, as various seaweeds constitute a critical ingredient in toothpaste, puddings, makeups, medicines, soaps, pet food, and plant fertilizers. That the worldwide seaweed harvest is a massive and ever-growing industry, particularly as we deplete the other ocean bounties we have long enjoyed. Seaweed may not be as prominent a natural phenomenon to most people as bees, frogs, or polar bears, but the collective health of the manifold macroalgae species betrays even more profoundly, perhaps, how significant our human impacts on the planet continue to be in the Anthropocene.


The Learned Pig


Here’s where my attention turns from sargassum to rockweed (Ascophyllum nodosum), one of the most aggressively and controversially harvested seaweeds in the United States. Rockweed is a brown macroalgae that inhabits and often dominates rocky coastal shorelines from the Canadian Arctic, Greenland, Iceland, and Norway to Portugal and the northeast coast of the United States south to New Jersey. In stark contrast to the sargassum of my shores, rockweed uses a sturdy little foot called a holdfast—which may be up to 400 years old!—to attach itself to rocks and ledges in the intertidal zone. At low tide, rockweed’s layers of fronds provide a blanket for various species, protecting them from desiccation. At high tide, the rockweed branches rise and sway in the currents sometimes higher than two meters, like leaves in forest trees, providing habitat to 34 species of fish and over 100 invertebrates, many of which constitute critical food sources to fish and birds, perhaps most notably the eider duck. “Here,” Carson writes in The Edge of the Sea, “all other life exists within their shelter.”

I try to hold in my mind what I learn about sargassum along my sandy southeast coast and what I learn about rockweed along the more hardscrabble northeast coast. If the trouble with sargassum today is its overabundance, the trouble with rockweed may be its scarcity. With the exception of the lobster industry, fisheries in Maine over the past half-century have either collapsed (e.g., cod) or face increasingly strict regulations on account of their decline (e.g., eels, urchins, scallops). These facts on the ground have only incentivized the rockweed harvest, particularly since 1999, when the Canadian company, Acadian Seaplants Limited, began its industrial-scale operations in the state. Recognizing the peril of the escalating rockweed harvest to the entire biome, Robin Hadlock Seeley, the leading rockweed scientist, organized the Rockweed Coalition with others in 2009. The coalition has essentially been fighting against proponents of the industrial harvest ever since with varying degrees of success. To ensure the regeneration of harvested rockweed, Seeley and her allies convinced the Maine legislature early on to pass a law that prevents harvesters statewide from cutting blades any closer to the holdfasts than sixteen inches. Prior to that, some harvesters had dragged cutting rakes behind their skiffs to rip the seaweed straight off the rocks, holdfasts and all. The coalition also spearheaded the implementation of the state’s strictest regulations in Cobscook Bay on the Canadian border, dividing the area into sectors and prohibiting harvesters from removing more than seventeen percent of the rockweed from any given area each year. They would like to see the adoption of these management practices statewide. Yet this seems unlikely.

Who owns the rockweed? The answer hinges upon whether rockweed ought to be considered a plant or an animal.

Exactly who owns the rockweed has been the primary source of contention and litigation between the industry and environmentalists. The answer to the question hinges upon whether rockweed ought to be considered a plant or an animal. If it’s a plant, according to laws dating back to colonial times, the upland property owners would own the rights to rockweed in the intertidal zone. If rockweed were considered an animal, however, it could be harvested from the sea at high tide by anyone, just like most fish and crustaceans. The arguments for each position are actually more complex than you might imagine, setting aside whether the very name of Acadian Seaplants ought to constitute a concession from the get-go. In any case, Judge Harold Stewart II of Maine’s Superior Court sided in 2017 with the landowners and the Rockweed Coalition, noting that the rockweed harvest was “no more a fishing activity . . . than is harvesting a tree the same as hunting or trapping wildlife.” Acadian Seaplants appealed, but the state Supreme Court in March of 2019 affirmed by unanimous decision the lower court’s ruling, which means that rockweed statewide cannot be cut without the express permission of the landowners. The Rockweed Coalition, in the meantime, has enlisted hundreds of these landowners to its cause, which will likely limit the harvest moving forward. All the same, sympathies among the citizenry, as expressed through other organizations such as the Downeast Lobsterman’s Association and the Maine Seaweed Council, tend to straddle the environmentalist and industry positions.




Spring in Florida, meanwhile, gradually yields to summer and a daily riot of sargassum continues to plague my local beach. Storm doesn’t seem to mind, but I need an escape from the malodorous seaweed and the scorching temperatures. Plus, all this reading about rockweed from my faraway remove in the subtropics makes me want to see this notorious seaweed. Fortuitously, my sudden interest in macroalgae coincides with our family plans to visit Acadia National Park in Maine. As soon as we arrive at Bar Harbor on Mount Desert Island, I take our nine year-old daughter to the granite shore so I can check out the rockweed and she can hunt for sea glass. (We all have our hobbies.) It’s low tide, so this elbow of coastline in town advertises in full view its ledges and boulders, coated with brown seaweed that I probably wouldn’t have taken much note of a year ago, or taken for mere detritus washed onto the outcroppings, but which I now know to be rockweed secured by holdfasts rather purposively to their rocks.

While my daughter Eva hunts successfully for sea glass amid the pebbles, I turn over fronds of the matted brown stuff, upsetting tiny crabs and other creatures which had sought out the shelter of the thickets. I marvel at the specific architecture of this seaweed, the length and shape of the individual blades festooned with rubbery air bladders I squish between my fingers. It’s easy to imagine what these patches of rockweed must look like at high tide, lolling in the current, how Carson could describe the intertidal zone as an “underwater forest” to render the ecosystem more real to landlubbers like me. I look up and notice sharp little seabirds, black and white guillemots, skittering between patches of weeds below the tideline, a cormorant diving for its prize, a lobster boat beyond trailing a fizzy wake, and I sort of “get it” in a way I haven’t before what Carson’s driving at throughout The Edge of the Sea with her languorous sentences that tend to sweep in several creatures in a single breath. In this way, she emphasizes the interconnections between all flora and fauna in the rockweed zone:

When covered at high tide, the rockweeds stand erect, rising and swaying with a life borrowed from the sea. . . . Down below those floating tips small fishes swim, passing between the weeds as birds fly through a forest, sea snails creep along the fronds, and crabs climb from branch to branch of the swaying plants. It is a fantastic jungle, mad in a Lewis Carroll sort of way.

As Eva and I continue along the shore path, pausing time to time to explore new sections of the intertidal zone, tidal pools populated by periwinkles, green crabs, sea stars and other creatures I can’t be sure of (anemones? urchins?), I read the signage calling our attention to the ostentatious, 19th century “cottages” here and there owned by such and such personage, the site of an aborted seawall construction project, the shoal where a luxury liner ran aground a hundred years ago, the enormous boulder distinct in its chemical composition from the other local boulders and deposited here by a glacier during the last Ice Age. But the signage on the whole, what with my newfound appreciation for seaweed, makes me wonder whether we tend to underscore all the wrong things with the signs we post about. There ought to be a sign drawing my lazy eyes toward our more commonplace wonders, such as these perfectly ordinary Maine rocks haired over with tendrils of rockweed.




I want to probe further the thingness of seaweed, itself.

What better way to do this than to start eating some of it. My local sargassum, unfortunately, represents a poor candidate for my plate as the fronds hold relatively large amounts of heavy metals. Yet the market keeps growing in the United States for other seaweeds as a health food. I peruse the websites of Ironbound Island Seaweed, Maine Seaweed, Maine Coast Sea Vegetables, and Heritage Seaweed. These are all small outfits whose few employees harvest little if any of the embattled rockweed and clip from the rocks and ledges only modest and sustainable amounts of the other seaweeds they dry and sell whole to restaurants, food markets, and home chefs in the United States. (Acadian Seaplants, by contrast, processes its industrial-scale rockweed harvest to a fine powder or liquid, then sells most of it overseas to China as animal feed or plant fertilizer.) I’m fairly astonished by how many edible macroalgae species exist in the Atlantic Ocean—Irish moss, kombu, laver, alaria, kelp, and dulse—and that I can purchase from one of these companies at the click of a mouse.

But I won’t need to mail-order my first batch of seaweed. For while we’re still on Mount Desert Island in Maine, I notice the Ironbound Island Seaweed products for sale at Beech Hill Farm, an organic farm owned by the nearby College of the Atlantic, a small college dedicated to the study and practice of human ecology. I pluck from the shelves several large packages of dried kelp, dulse, wakame, and kombu, eliciting a skeptical gaze at the counter from my wife, Wendy, who at this stage of our marriage has gotten used to humoring me for such strange enthusiasms.

I savor the sharp iodine notes against my tongue, which segue to a milder asparagus flavor, then a toasted nut finish.

As soon as we arrive back home in Florida I set about preparing a variety of dishes featuring seaweed. There’s no shortage of recipes online, many of which are featured on the websites of the seaweed purveyors listed above. I manage to prepare a rather delicious tofu, mushroom, and bok choy stir-fry featuring wakame and a not so delicious miso soup featuring kombu. Word to the wise: kombu, tough as leather, ought only to be used as a thickener for soups and removed before serving. Next, I simmer a colorful medley of beans with kelp for hours until the kelp tenderizes the beans and dissolves into the scrumptious stew, to which I add sautéed garlic and onion. But the seaweed I truly fall in love with is the purple and rose-colored dulse. Dulse (Palmaria palmate) is a red macroalgae that grows on cliffs, shaded crevices, and pools in the northern intertidal coastlines of the Pacific and Atlantic Oceans. Its paper-thin, deeply indented fronds, Carson writes, “bear a crude resemblance to the shape of a hand.”

Dulse is also rich in potassium, iron, iodine, and trace minerals, which explains why farmers in Ireland and Iceland have harvested dulse from their rocky coasts for food for the past 1500 years, even chewing dried dulse leaves whole like tobacco. The supple texture of the dried seaweed proves tempting enough that I plop one small frond directly into my mouth, too, straight out of the bag. I savor the sharp iodine notes against my tongue, which segue to a milder asparagus flavor, then a toasted nut finish. I heat a cup of dulse in a cast iron pan over a high flame for just a few moments until the seaweed begins to smoke and then I incorporate the toasted fronds into a milk-based seafood and potato chowder. The pan-fried dulse lends a sort of bacony flavor to the chowder, which my whole family loves, especially our college-age son, Henry.




All the same, it’s not so easy to return to south Florida from Maine in the middle of August, as anyone who’s ever been to south Florida in the middle of August might imagine. It’s not only the stultifying heat or the still-thick matts of sargassum that bring me down. No sooner do we settle in than we must evacuate to Georgia as Hurricane Dorian, a Category Four storm, bears down upon our coast from the Caribbean Sea. It will largely spare Florida, though it will decimate parts of the Bahamas, killing many people in its path. The hurricane dominates the news on TV for several days given its fearsome power and the length of time that it lingers over our eastern seaboard, wreaking havoc in the Carolinas and even pounding Maine with rain before finally veering offshore into the north Atlantic. As meteorologists and political pundits squabble over whether, and to what extent, we might attribute our ever-strengthening tropical weather systems to global warming, as my family and I remain holed up in an Atlanta hotel room, I can’t help but think about the Great Atlantic Sargassum Belt that awaits me back home.

Specifically, I reflect upon the various possible causes for the sargassum bloom currently under review by scientists (which include the warming seas), and the cavalier way that many of us non-scientists at the dog beach have tended to dismiss our culpability over the past several months. It’s the fertilizer in Brazil, the fires in Africa, all of my neighbors and I seem anxious—too anxious—to believe.

“Fucking Brazil,” has become a popular refrain at my local beach.

While these faraway scourges may be among the leading sources of the bloom, it’s just as true that we in Florida contribute plenty of the nitrogen to our local waters that at the very least has exacerbated our global sargassum problem. Land-based nutrients from agricultural fertilizers and the runoff from other industries (e.g., cattle ranching, phosphate mining) flow into the Atlantic and Gulf of Mexico from our lakes, rivers, and canals. We also continue to spew our partially treated wastewater just offshore in Miami-Dade, Broward, and Palm Beach counties through various outfall pipes. “Human sewage is creating a much bigger role than anyone wants to admit,” says Brian LaPointe, an algal bloom expert at Florida Atlantic University, the school where I also work. So yes, it may feel good to blame faraway culprits for the sargassum, but an honest appraisal suggests that we’ve made a fine mess of the coastline all by ourselves. While these thoughts swim in my brain, I notice on the beach one day for the first time in my twenty-plus years as a resident an exposed sea turtle nest, the eggs errantly laid and buried below the tideline, a few dead would-be hatchlings still partly encased within their eggshells, torn open by the surf. I must shoo Storm away from the fragrant carnage. I can’t prove it, of course, but it seems likely that the adult female turtle, discouraged and exhausted by the wide blanket of sargassum just above the tideline, chose to dig her nest and lay her eggs on the open sand within fatal reach of the incoming tide.

It all puts me in a dour mood.




It’s in the midst of this low mood of mine that it happens. I’m in my backyard refilling one of our birdfeeders when the first bee collides against my skull with a surprising level of force. A split-second later it stings my scalp. Then the bright pain of a second sting blooms just beside my left eye, and I’m sprinting back into the house, flailing at the bee still tangled within the thicket of my curly hair. I manage to shed the creature into the basin of my kitchen sink where it winds down like a toy and finally dies.

We’ve co-existed with the hive for several months as bees have had a rough go of it, lately, rougher than rockweed…

The bees that attacked me, I know, come from the large hive that colonized one of my woodpecker nest boxes I built and installed ten-feet high in one of our live oaks. We’ve co-existed with the hive for several months as bees have had a rough go of it, lately, rougher than rockweed, and as a local beekeeper, Adrian, assured us that European honeybees are typically rather docile. True enough, up until today. But I can’t risk any further the chance that they might attack my young daughter next. Within minutes of being stung, an icepack still firmly lodged against my eye, I’m on the phone with Adrian and he’s on his way to my house to remove the hive. He’s young, twenty-something, sports a prodigious beard, and goes by the nickname, the Bearded Beekeeper. Eva and I watch from a window inside the safety of our house as Adrian, atop his ladder in a protective suit, plies the hive with calming smoke, then removes the entire nest box from the tree, layers of honeycomb bulging out the entrance.

“The bees that stung me,” I ask him just after he shuts the rear hatch and I hand him his check, “they die right after that, right?”

“Right,” he says. It had always fascinated me that this might be true.

“Do you think they know they’re going to die before they sting you?”

“I do,” he says. “I do think that they know.” He pauses for a moment as he takes off his gloves. I can tell that he’s still thinking about my question, that he’s about to say something else, and he does.

“It’s all about the hive.”

It’s all about the hive. I marvel over Adrian’s words for days, weeks. The selflessness of bees! Such community!

It eventually brings my mind back to seaweed, and to us. It makes me wonder what the manifold creatures in the rockweed zone know of community. If the bees know, in their own bee-way, that it’s all about the hive, is it such a stretch to imagine that rockweed and its hundreds of plant and animal associates enjoy (if this is the best word) their own unique sense of community, as well (to the extent that we can imagine with our own senses the senses of rockweed and periwinkle and eider duck)? I weigh the ethic of the hive, and the ethic of the rockweed zone, against our presiding human ethic in the world that I know, which is to say south Florida, and to a lesser extent the country as a whole. It’s tough not to find us wanting by the standard of bees and seaweeds. While a hive-mentality is not something we ought to emulate too closely, I worry that we’ve careened headlong toward the other extreme of narcissistic individualism and that this might be the source of many of our problems, environmental and otherwise. We’ve grown ever more atomized and hardly enjoy any sense of community at all.

Yet it’s still a free country, last I heard. We can live however we want in the days, months, and years ahead. What if we decided that we wanted to live once again in true community and what if we extended that notion of community, as Aldo Leopold championed in the middle of the last century, to include the people, plants, and animals within and without our rather arbitrary national borders? Might we look at the Great Atlantic Sargassum Belt differently in this state and country if we considered Brazil and Africa, and the sargassum itself, to be a part of our “we,” a part of our hive? Might we greet all the approaching plagues more constructively, and humanely? As the Bearded Beekeeper says, “It’s all about the hive.”




Summer eventually yields to fall, the broiling heat in Florida subsides, the sargassum thins from my swatch of shoreline (perhaps on account of the cooling ocean), and the water blues up. My neighbors return to the beach and we can all enjoy a nice swim once again without battling the tangled nets of sargassum, their associated sea pests, or the rotten egg stench. On one such glorious October day, I exchange chipper hale and hearties with my dog beach pals Vanessa, and Richard, and Michelle, and Emmanuel, essential members of the human community I’ve managed to forge in the subtropics. Our dogs reacquaint themselves with one other, and with us. We walk the beach and collect, along with our pets’ waste, the plastic refuse that’s washed up on shore. In this small way, we feel that we do our part. I watch a flock of sanderlings chase the outgoing surf, then retreat from an incoming wave—chase and retreat, chase and retreat—drilling the wet sand for morsels. Schools of mullet have returned from their northern range and puncture the water’s surface in silver commas. I see an osprey dive for its prize, a kite-boarder riding the wind beyond along with a few terns. It’s easy to think, if only for this brief spot of time, that everything under the sun is and will always be okay.


Image credit: Chris Moody, Sargassum muticum (2011), via Flickr

This is part of ROT, a section of The Learned Pig exploring multispecies creativity through modest tales of collaboration and coexistence amidst world-ending violence and disorder. ROT is conceived and edited by Julia Cavicchi.


The Learned Pig