Kelp, Trophic Cascades, and Climate

By Lambert Strether of Corrente.

Because I’m a fan of povidone-iodine as a Covid prophylactic (though disclaiming any ability or desire to give medical advice), I thought I would investigate kelp, since I thought that iodine was derived from kelp. Alas, it once was, but that’s “no longer economically viable.” (A substance derived from kelp, algin, is used as an emulsifying and bonding agent in toothpastes, shampoos, salad dressings, puddings, cakes, dairy products, frozen foods, so if you’re a ranch dressing fan, read on.) So, normally when I wander into the biosphere I get lost and don’t come out where I expect; with kelp, I got lost on my very first steps in!

Kelp forests are very beautiful:

And here is a video (whose soundtrack could do double duty as a sleeping aid):

“Wow, what an amazing plant!” you might be tempted to say, but kelp (genus Macrocystis) is a large brown algae, not a plant, but a heterokont (so-called for the flagellated cells[1] that most produce at some point in their lifecycles). Amazing algae[2], then. From

Since the giant kelp is not a plant, it does not have roots. Instead, it obtains all of the necessary nutrients directly from the water and is attached to the rocky bottom by a structure known as a holdfast. Like plants, however, the giant kelp harvests the sun’s energy through photosynthesis and does not feed on other organisms. This species is one of the fastest growing species in the world, and under perfect conditions, it has been known to grow up to two feet (60 cm) in a single day. Once and individual giant kelp reaches the sea surface, it continues to grow horizontally, floating in large mats that shade the water column and sea floor below. In order to remain upright, each giant kelp blade (leaf) includes a gas-filled pod that floats. Several individuals growing together can create dense forests that are an important ecosystem in temperate, coastal areas where they live.

Kelp forests range along 25% of the Earth’s coastlines. Here is a map:

(You will notice no kelp in the tropics; kelp like colder waters.) NASA’s Earth Observatory describes kelp forests:

Giant kelp forests are among Earth’s most productive habitats, and their great diversity of plant and animal species supports many fisheries around the world. The kelp, or Macrocystis, that make up these underwater forests truly are giant. They are the world’s largest marine plants and regularly grow up to 35 meters (115 feet) tall; the largest giant kelp on record stood 65 meters (215 feet) tall. Divers have compared swimming through mature kelp forests to walking through redwood forests.

Unlike redwoods, giant kelp are ephemeral. They live for seven years at most, and often they disappear before that because of winter storms or over-grazing by other species. As fishermen know, giant kelp forests can appear and disappear from season to season, from year to year.

NOAA amplifies the species diversity of kelp forests:

In kelp forests, the most commonly found invertebrates are bristle worms, scud, prawn, snails, and brittle stars. These animals feed on the holdfasts that keep kelp anchored to the bottom of the ocean and algae that are abundant in kelp forests. Sea urchins will often completely remove kelp plants by eating through their holdfasts [ouch!]. Other invertebrates found in kelp forests are sea stars, anemones, crabs, and jellyfish.

Hold that thought on sea urchins. More species:

A wide range of fish can be found in kelp forests, many of which are important to commercial fishermen. For example, many types of rockfish such as black rockfish, blue rockfish, olive rockfish, and kelp rockfish are found in kelp forests and are important to fishermen.

A wide range of marine mammals inhabit kelp forests for protection and food. Sea lions and seals feed on the fish that live in kelp forests. Grey whales have also been observed in kelp forests, most likely using the forest as a safe haven from the predatory killer whale. The grey whale will eat the abundant invertebrates and crustaceans in kelp forests. One of the most important mammals in a kelp forest is the sea otter, who takes refuge from sharks and storms in these forests. The sea otter eats the red sea urchin that can destroy a kelp forest if left to multiply freely.

Kelp forests are a natural buffet for birds such as crows, warblers, starlings, and black phoebes which feed on flies, maggots, and small crustaceans that are abundant in kelp forests. Gulls, terns, egrets, great blue herons, and cormorants dine on the many fish and invertebrates living in the kelp. Kelp forests also provide birds with a refuge from storms.

Ecologists have conceptualized the relations between such species more formally as a “food web.”

A food web consists of all the food chains in a single ecosystem. Each living thing in an ecosystem is part of multiple food chains. Each food chain is one possible path that energy and nutrients may take as they move through the ecosystem. All of the interconnected and overlapping food chains in an ecosystem make up a food web.

Organisms in food webs are grouped into categories called trophic levels. Roughly speaking, these levels are divided into producers (first trophic level), consumers, and decomposers (last trophic level).>

Here is a diagram of a food web that, as it happens, includes kelp, sea urchins, and sea otters:

Turning to paradigms, “as it happens” is, in fact, not a coincidence. The otter -> sea urchin -> kelp relationship is the basis for a paradigmatic example of what ecologists call a a “trophic cascade.” From the Fish and Wildlife Service:

In his famous essay, “Thinking like a Mountain,” Aldo Leopold recounts an epiphany he experienced while watching the “fierce green fire” fade from the eyes of a dying wolf: “I thought that because fewer wolves meant more deer, that no wolves would mean hunter’s paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view.” The larger view that Leopold came to see, and that he tried to help others see, was that the predators his contemporaries vilified and systematically killed were an integral part of the ecosystem—important not only to the plants that the deer consumed but also, seemingly paradoxically, to the deer themselves. “Since then,” Leopold writes, “I have watched the face of many a newly wolfless mountain, and seen the south-facing slopes wrinkle with a maze of new deer trails. I have seen every edible bush and seedling browsed […] to death. I now suspect that just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer.”

Like wolves, sea otters were systematically eliminated from most of their native range…. Whereas sea otters were killed during the fur trade for their lush pelts, not for competing with humans for prey, the effects of their removal were parallel to those following the elimination of wolves. [Sea otters eat] the equivalent of about 25 percent of their body mass each day. Calorie-rich sea urchins, herbivores that consume algae, are one of their preferred prey. Just as deer can proliferate and radically alter the landscape in the absence of wolves, hordes of hungry sea urchins, when released from sea otter predation, can turn kelp forests that support a myriad of organisms into urchin barrens. Although factors such as storms can also influence kelp abundance, where there are sea otters, kelp tends to increase. Given their large-scale community effects, sea otters, like wolves, are considered a keystone species.

Removing the keystone, predator, species (wolf or otter) causes a “trophic cascade,” as the consumer species proliferate (deer, urchins) and consume the producer species, collapsing one of the chains in the food web (as many suburbanites have come to learn. See other examples of the same cascade here, here, and here[3]).

Otters -> Sea urchins -> kelp is, in fact, a paradigmatic case of a trophic cascade (it’s Wikipedia’s go-to example for that entry). Interestingly, the paradigm is now under attack[4]. From February of this year in, “New research on sea urchins challenges long-held assumptions about marine reserves,” which provide a nice natural experiment. Sorry to quote so much of it:

But a new study by [Katrina Malakhoff, a doctoral student in UC Santa Barbara’s Interdepartmental Graduate Program in Marine Science] and her advisor, Robert Miller, suggests that the truth is much more nuanced. The researchers examined urchin populations inside and outside marine reserves, where protection from fishing should have enabled urchin predators to rebound and control their populations. But instead of finding fewer urchins, they found that one species was unaffected by the reserves, while the other flourished…. “We predicted that by protecting these areas we’re increasing the number and density of urchin predators that will then control urchin populations and prevent them from overgrazing the kelp forest and turning it into an urchin barren,” Malakhoff said. She sought to investigate this assumption, as well as the tendency of scientists and resource managers to lump the two species together and treat them as ecologically equivalent.

The reserves seemed to have no affect at all on unfished purple urchin populations. What’s more, instead of decreasing in numbers, red urchins proliferated within the borders of some marine reserves. Their size, number and density increased once they no longer faced fishing pressures. Reserves also had no clear effect on giant kelp density.

“I was pretty surprised,” Malakhoff said. “It contradicted what I expected to be happening in the kelp forest.” If a rise in predation within the reserve influenced urchin populations, then both species should have decreased in number, and there ought to have been fewer small urchins, which provide an easier snack for predators.

“There’s a simplistic picture that’s been promulgated of kelp forests versus urchin barrens, and that predators are preventing this phase shift from happening,” Miller said. The corollary is that, by restoring predator populations, reserves should allow the lush kelp forests to return.

Other studies have documented that the urchins’ predators are thriving under the reserves’ protection. The new results indicate that predation probably isn’t the primary factor controlling urchin populations. For instance, larval dispersal and recruitment—as well as the oceanographic regimes that affect them—likely have greater effects on urchin populations, Miller said.

This study invites scientists to reconsider how common trophic cascades are, and whether marine reserves will always induce them. “Katrina’s study adds to a growing body of evidence that suggests that trophic cascades are confined to a pretty narrow set of situations in the natural world,” Miller said.

The two researchers acknowledge that some of their fellow scientists and resource managers might be reluctant to accept their conclusions. “The relationship between marine reserves and trophic cascades has approached paradigm status,” Miller explained, “and it’s always difficult to push back against a paradigm.”

Of course, I have paradigm shifts very much in mind, having followed the aerosol v. droplet tranmission controversy with great interest over the last year. But let’s remember that saying a theory is a paradigm shift means neither that the theory is correct nor that the paradigm shift will take place.

Turning finally to climate, kelp forests are enormous carbon sinks:

The capacity to draw CO2 from the atmosphere has added “climate mitigation” to kelp’s list of benefits. When we talk about ways oceans can sequester carbon, the conversation typically revolves around mangroves, salt marshes, and seagrass meadows. But “the magnitude of carbon sequestered by algal forests is comparable to that of all those three habitats together,” says Carlos Duarte, a professor of marine science at the King Abdullah University of Science and Technology in Saudi Arabia. “Algal forests should not be left behind. They have been hidden for much too long.”

There’s a lot we still don’t understand [of course] about how kelp store CO2. But researchers are starting to build a better picture of this giant seaweed and how we might improve its capacity to help tackle climate change.

WaPo reinforces:

Giant kelp is among the best organisms on the planet for taking planet-warming gases out of the atmosphere. Buoyed by small, gas-filled bulbs called “bladders,” these huge algae grow toward the ocean surface at a pace of up to two feet per day. Their flexible stems and leafy blades form a dense underwater canopy that can store 20 times as much carbon as an equivalent expanse of terrestrial trees.

Unfortunately, since kelp likes cold water, global warning threatens it:

A steady increase in ocean temperatures — nearly 3 degrees Fahrenheit in recent decades — was all it took to doom the once-luxuriant giant kelp forests of eastern Australia and Tasmania: Thick canopies that once covered much of the region’s coastal sea surface have wilted in intolerably warm and nutrient-poor water. Then, a warm-water sea urchin species moved in. Voracious grazers, the invaders have mowed down much of the remaining vegetation and, over vast areas, have formed what scientists call urchin barrens, bleak marine environments largely devoid of life.

The Tasmanian saga is just one of many examples of how climate change and other environmental shifts are driving worldwide losses of giant kelp, a brown algae whose strands can grow to 100 feet. In western Australia, increases in ocean temperatures, accentuated by an extreme spike in 2011, have killed vast beds of an important native kelp, Ecklonia radiata. In southern Norway, ocean temperatures have exceeded the threshold for sugar kelp — Saccharina latissima — which has died en masse since the late 1990s and largely been replaced by thick mats of turf algae, which stifles kelp recovery. In western Europe, the warming Atlantic Ocean poses a serious threat to coastal beds of Laminaria digitata kelp, and researchers have predicted “extirpation of the species as early as the first half of the 21st century” in parts of France, Denmark, and southern England.

Fortunately, restoration efforts are taking place (and in Maine, too). Yes, it’s a startup, but that’s where we are:

Adam Baske strolls through a warehouse on the coast of Harpswell, Maine. Surrounding him are trays of oysters with water circulating between them in small tubes. In another room stands rows of eight-foot-tall tanks of algae growing at different stages. The algae will be food for the oysters. If you’ve never seen a shellfish hatchery, this one looks pretty typical. But it’s not. This year, they’re planning to harvest something new—atmospheric carbon.

His company, called Running Tide Technologies, plans to grow vast quantities of seaweed in drifting ocean mini-farms—farms that the company plans to sink to the bottom of the ocean.

“So this is basically taking the emissions of our fossil-fuel burning, locking them back up into the structure of the kelp and sending it back to the bottom of the ocean, where, you know, it’s at least locked up for hundreds to thousands of years because of the great pressure and the slow movement of the water in the deep ocean.”

Kelp, like other plants, uses photosynthesis to extract carbon dioxide from the atmosphere. Colette Feehan, a marine ecologist at Montclair State University, who does not work with Running Tide Technologies, says that kelp is a no-brainer when it comes to carbon sequestration.

“The productivity of kelp forests has been found to be comparable to tropical rain forests, meaning that they put on a great deal of biomass, and that biomass is stored carbon.”

It can do this because it grows fast (about a foot per month). It also quickly sinks to the seafloor. Once there, it degrades very slowly.

Trees, on the other hand, store carbon but ultimately release it back to the atmosphere when they die and decompose. Kelp can stay effectively buried, its carbon entombed by the crushing pressure and lack of oxygen, for hundreds, maybe thousands of years.

“As a climate change mitigation strategy, there’s mounting evidence that this is a good approach. These forests aren’t taking up land that would otherwise be used for agriculture or housing. So there’s really no negative side to growing kelp forests.”

And here is a similar project in Tasmania, but with a permaculture (1) twist:

“In collaboration with the Climate Foundation as part of its work to regenerate food security, ecosystem services and mitigate climate change, our study aims to establish whether there’s any chance of restoring these important marine communities by identifying individual giant kelp plants that may be genetically better adapted to warmer sea temperatures,” Professor Johnson said.

Dr. Brian von Herzen, Executive Director of the Climate Foundation, said “Marine Permaculture development programs like these increase our collective capacity to regenerate life in the oceans and ensure healthy ecosystems and climate for generations to come.”

Project researcher and Climate Foundation Postdoctoral Fellow Dr Cayne Layton, said that in 2012 southeastern Australia’s giant kelp forests were listed by the Australian Government as an endangered marine community, the first such listing for a marine community in Australia.

“Giant kelp were the foundation for marine communities along much of Tasmania’s East Coast, creating complex habitats that once supported key species of conservation or commercial value, from weedy sea dragons to rock lobsters and abalone,” Dr Layton said.

“Active restoration of these now degraded and disappearing habitats represents a potential approach for conservation of giant kelp forests while at the same time offering new commercial possibilities.

“The same techniques that underpin restoration may also be able to facilitate the development of giant kelp Marine Permaculture for commercial harvest and integrated multi-trophic aquaculture.

Cool! (Note that selecting for kelp that can live in warmer waters seems to be an angle the Maine project has not considered.

Maybe. Worth a shot. One of the nice things about using kelp farms for carbon sequestration, as opposed to tree plantations (I won’t call them forests) is that real estate issues do not arise; the lunatic BECCS project, for example, needed real estate the size of the Indian subcontinent for its trees, so I don’t think so..

* * *

I don’t quite know how to bring this serendipitous trip through the kelp forests to an conclusion, so I will say, with Frank Herbert’s Fremen, “now it’s complete because it’s ended here.” I hope it was fun and useful!


[1] Life is too short to go through the sex life of kelp, but here is a chart of kelp’s life cycle:

The meiospores at top right look like flagella to me.

[2] Also amazing is that as of 2010 is but one single fossil of kelp. Today, the fossil record is considered “sparse,” “as these organisms do not produce hard parts, such as certain calcified red and green algae, nor do they produce resistant spores. Also, in the absence of pigments, fossil brown algae may be almost impossible to distinguish from these other algae, since there are many morphologically convergent forms among the three groups. These difficulties are compounded by the lack of trained paleobiologists who specialize on algae, or of phycologists who examine fossils.”

[3] Thinking of Nabokov’s famous parable where an ape, given charcoal and paper, drew the bars of his cage, consider this passage from Scientific American’s “Living in a Landscape of Fear: How Predators Impact an Ecosystem“:

The keystone species concept lies at the heart of the HSS debate. When Robert Paine introduced it in 1969, he envisioned its mechanisms as a dominant predator consuming and controlling the abundance of a particular prey species and a prey species competing with other species in its trophic class and excluding them from the community.

Granted, I’m going all PoMo here, but this reminds me of academic politics, although some departments (***cough*** economics ***cough***) are no doubt far worse than others. Speculating freely, one might wonder whether these academics find predator-prey relations so powerful and illuminating as an analytical tool because they mirror the relationships that matter most to them in their professional lives. Department chairs, red in tooth and claw, as it were.

[4] One obvious rejoinder would be to attack the distinction between producers (of nutrients; plants) and consumers (herbivores), where the producers are seen as implicitly passive. But from Michael Pollan’s Botany of Desire, we know that’s not so: Plants, as it were, cultivate our senses. See also the communications networks of trees. Granted, kelp lack roots, but perhaps they have evolved other channels. Plants are in no way passive, and I don’t see why the same should not be true of heterokonts too.

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About Lambert Strether

Readers, I have had a correspondent characterize my views as realistic cynical. Let me briefly explain them. I believe in universal programs that provide concrete material benefits, especially to the working class. Medicare for All is the prime example, but tuition-free college and a Post Office Bank also fall under this heading. So do a Jobs Guarantee and a Debt Jubilee. Clearly, neither liberal Democrats nor conservative Republicans can deliver on such programs, because the two are different flavors of neoliberalism (“Because markets”). I don’t much care about the “ism” that delivers the benefits, although whichever one does have to put common humanity first, as opposed to markets. Could be a second FDR saving capitalism, democratic socialism leashing and collaring it, or communism razing it. I don’t much care, as long as the benefits are delivered. To me, the key issue — and this is why Medicare for All is always first with me — is the tens of thousands of excess “deaths from despair,” as described by the Case-Deaton study, and other recent studies. That enormous body count makes Medicare for All, at the very least, a moral and strategic imperative. And that level of suffering and organic damage makes the concerns of identity politics — even the worthy fight to help the refugees Bush, Obama, and Clinton’s wars created — bright shiny objects by comparison. Hence my frustration with the news flow — currently in my view the swirling intersection of two, separate Shock Doctrine campaigns, one by the Administration, and the other by out-of-power liberals and their allies in the State and in the press — a news flow that constantly forces me to focus on matters that I regard as of secondary importance to the excess deaths. What kind of political economy is it that halts or even reverses the increases in life expectancy that civilized societies have achieved? I am also very hopeful that the continuing destruction of both party establishments will open the space for voices supporting programs similar to those I have listed; let’s call such voices “the left.” Volatility creates opportunity, especially if the Democrat establishment, which puts markets first and opposes all such programs, isn’t allowed to get back into the saddle. Eyes on the prize! I love the tactical level, and secretly love even the horse race, since I’ve been blogging about it daily for fourteen years, but everything I write has this perspective at the back of it.


  1. Wukchumni

    Very informative!

    A few years ago I was soaking with friends @ Iva Bell hot springs and one of them described nearly dying when snagged in a kelp forest while skin diving, and you could tell she was quite shaken from the event a few years prior…

    I didn’t help matters by inquiring:

    ‘Did you seek kelp?’

    She reached over and dunked my head under the 104 degree water in response, Naegleria fowleri play.

  2. Jeremy Grimm

    Humankind is not a keystone predator, but the predator above all predators — the most Dangerous Game. Deer and wolves are an easy consideration. Humankind will as fondly eat deer as will wolves. The growing pressures on the poor of Humankind to find meat strongly drives human hunters to hunt. But human laws or stupidity like the prion spreading feeds used to most cheaply feed farmed deer, elk, and moose curtail human hunting of deer. The sea urchin roe had been exported to Japan as high end sushi. What happened to that trade? And are there no other uses for sea urchin proteins. If the Japanese are fond of this delicacy how should we be so immune to it.

    As oceans warm as they are and will and will continue to warm perhaps we could find a tiny bit of money to support a few postdocs in attempting some genetic modifications of kelp — brown or perhaps red — to adapt kelp to the warming waters. In past eras the climate has changed relatively slowly, at least slowly enough for many species to adapt. That is not the way of the future that looms but few decades beyond the present. Instead of conquering Nature, Humankind must help her.

    1. Alex Cox

      The sea urchin trade is still a very big deal, I think. It used to be impossible to get uni in an American sushi restaurant near the end if the year. According to the chefs the Japanese bought up the worldwide catch as it was a seasonal specialty – and popular throughout the year since it is so delicious.

      Thank you Lambert for this fascinating report!

  3. coboarts

    I read an article about the reintroduction of otters to a kelp ecosystem, might have been Monterey Bay, might have read it here, can’t find it, but everything got its health back… But, this is the point I’d like to make; computer models are worse than useless, because GIGO. Like this, “We predicted that by protecting these areas we’re increasing the number and density of urchin predators that will then control urchin populations and prevent them from overgrazing the kelp forest and turning it into an urchin barren,” (…) I once watched a YouTube of a physicist who was asked about the potential to model every interaction of the physical universe – he answered that it would take a computer the size of the universe. So, perhaps those that promote the religion of Science need to be demoted or at least the computer modeling with which they are intoxicated. It looks like trial and error, observations over time, and even perhaps common sense, like nature isn’t stoopid… are better adapted to reality.

  4. Sub-Boreal

    Thank you for highlighting this fascinating system.

    Although I’m a pretty hardcore terrestrial kind of guy, I learned a lot about this 2nd-hand when I spent much of the summer of 2015 working from a research station in coastal BC where some of the other field people were studying the impacts of sea otter recovery.

    I only managed to see the otters from a distance, but I certainly was impressed. The adults, I was told, were comparable to a German shepherd in size and weight. So if a critter that big was trying to stay warm while immersed in the North Pacific all day, no wonder they need to strip the shellfish populations so efficiently!

    One of the knock-on effects of sea otter extirpation during the hey-day of the fur trade was to leave a lot more seafood for everyone else in the neighbourhood, including the local First Nations communities. With the recovery of the otters, there’s now a lot less available for human subsistence. The more plentiful supply that lasted for a several decades was not going to last if the otters returned, and apparently this has created some unhappiness in those communities, along with annoyance that with lots more kelp about, it’s a nuisance for getting around in small boats! (This sounds like yet another example of the “shifting baseline syndrome”: In that classic paper, a fisheries scientist noted how humans have short memories and tend to normalize what may be only transient conditions, in this instance, lots of shellfish and not so much kelp.)

    More information about the complexities of coexistence between sea otters and coastal communities ( ) and the recognition of yet another player in the cascade ( )

  5. drumlin woodchuckles

    How fast can certain fresh-water-borne plants grow? Plants like water hyacinth? How much carbon can they downsuck and hold for sequestration?

      1. drumlin woodchuckles

        Salmon rivers seem like a uniquely bad place to have water hyacinth. Still, I wonder if water hyacinth could be ground up and mixed with other compostable carbon-rich plant-waste and composted into a sellable usable farm or-at-least garden compost product. That would make controlling water hyacinth pay for itself and incentivize harvesting enough of it steadily enough to end its damage-doing in these rivers.

        If it wouldn’t work out, then that’s a thought to give up on.

          1. drumlin woodchuckles

            What if we set up ponds in the South with controlled inlet and outlet water access so no water hyacinth could escape from those ponds.

            Then we could grow water hyacinth for harvest on those ponds.

            And then we could plant kudzu all around the border of those ponds. And let the kudzu grow out over the water hyacinth. The kudzu would race to cover the water hyacinth and the water hyacinth would race to outgrow and poke up above the kudzu floating laterally on the layer of water hyacinth.

            And every so often, we could reel in the long vines of kudzu and the matted rafts of water hyacinth that the kudzu is growing over and floating on. And that way get even more green-plant-matter production at the same time.

  6. timbers

    NOW vitamins sells powdered kelp. It comes with a tiny and I do mean tiny spoon which is equal to one dose. One dose contains about 3 time the US RDA, and the bottle contains about 4,000 servings. So clearly one bottle will last you years. Since the US RDA is a fraction of what the Japanese consume – which appears to benefit them – you have the option ingesting a much higher, Japanese size quantity if you choose, because you have a huge supply in just one normal size vitamin bottle.

  7. drumlin woodchuckles

    Growing and sinking vast amounts of kelp to the sea floor would certainly take some carbon out of the game for a while. If such kelp were treated as a purely “safe waste”, then the project of growing and sinking that much kelp would have to be paid for, and certainly could be.

    But given that kelp is already a source for plant-and-soil supporting and improving kelp meal and other kelp-derived products, I wonder whether turning all that kelp into soil-building/ plant-feeding meal and extracts would allow for even more carbon-suckdown overall in a two-step process ( grow the kelp, feed its remains to soil and plants) then the one-step process of growing it and sinking it to the sea floor.

    Certainly , processing all that newly grown kelp into meal and extracts and so forth would re-emit some of the carbon it captured. The question is . . . would feeding the kelp to the soil and the plants bio-support and bio-subsidize the growing plants so much and so effectively that it would cause the plants to suck down a greater amount of ” new carbon” than the amount of kelp-carbon re-emitted by cycling the kelp to land-based soil and plants. If it would, then re-looping the vast new kelp resource back to the land would overall net-net suck down and soil-store even more carbon than sea-burying the vast new kelp production would do.

    I hope someone studies that question and finds a real answer, one way or the other.

    1. CuriosityConcern

      Hi Drumlin,
      I think that is not a bad idea regardless of how a study would play out. I can imagine amending kelp meal into soil and not only growing good plants, but also perhaps growing beneficial soil microbes and fungi.
      Sign me up…
      I wonder if I harvested beach found kelp if I would have to worry about introducing salt into my soil?

      1. drumlin woodchuckles

        As a mere amateur, I don’t know but I do think . . . or at least suspect . .. . that if you were to pile up piles of kelp on the beach well above highest-tide, and let a few cycles of freshwater rain fall on it, that the salt on its surface would be carried off and back to the sea from whence it came. And then you could use that de-salted beach kelp could indeed be used in your garden.

        There are already companies which harvest and maybe even grow non-forest kelp and seaweed for processing into kelp meal and etc. Soluble extracts from ascophylum ( I think) are dried and sold under the name ” maxicrop” for redisolving and spray-feeding onto the foliage of plants.

        And as I sit here thinking, another idea occurs to me. If someone actually starts growing so much forest giant kelp that sinking it all could indeed lower the carbon-loads in the sea, which would encourage yet more skycarbon to enter the sea, from when it too could be kelp-sequestered and mass-sunk to the bottom of the sea . . . . what if they were to harvest all that kelp instead and squeeze industrial quantities of it under industrial pressure to extract all the liquid? That liquid could be used for plant feeding just like Maxicrop now is.

        And what about the dry kelp squeezings left over? Turn it into biochar! And move that biochar onto millions of square miles of land where it will sequester that carbon just as well as if it were sunk to the bottom of the sea. And more than that, by its physical structure it would house and shelter countless trillions of soil-building microbes who would then build up new Terra Preta all over the earth.

  8. PlutoniumKun

    On the health and iodine side of things, there is a long tradition in Ireland of hot kelp baths in spas. I think this was related to the obvious benefits of iodine – in the 19th Century there was a huge iodine industry in Ireland, it provided a lot of income for the poorest peasantry on the coast. The drying and roasting areas are still visible in many coastal places.

    One other seaweed – carrigeen – was long used as a folk treatment for respiratory infections in Ireland. As a child I was made drink a carigeen drink (often with poteen added) when I had a cold.

  9. The Rev Kev

    And in a case of serendipity, I was just watching on the news about the illegal kelp industry in Chile which is a major source of this material. One woman was throwing a hook on a rope to bring them in from underwater but there were boats loaded to the gills with kelp coming in and all illegal. Seems that it has all sorts of industrial applications. Beautiful image and video at the top of this article by the way.

  10. Boatwright

    FYI: Idaho’s governor just signed a bill that will allow elimination of 90% of its wolf population. Similar short-sighted politics vs nature is on the docket for several other states.

  11. TomDority

    Seems humans can’t get over themselves….maybe we can save that which we destroy ….yes we could if we could learn not to be so damned greedy and think we are the superior life form, the triumph of the universe, heaven sent.
    What is often quoted – ‘survival of the fittest’ – you heard it all before from every self-promoting financial firm, every succesfull business leader, and tough talking politicians. – I my view – the term quoted should be Survival of the most well adapted link in the chain of life.
    Thankfully, the scientific fields are finally uncovering the more complex interdependancies that created the extreme diversity inhabating every niche and everything, how the biodiversity enabled the occurance of human upon the earth and the realizations that without a healthy bio-diversity, without all the links and surrounding reinforcements of that chain, the more complex biology will be the first to drop out.
    I am sure that we humans will come up with ways to live on a world of slime level organisms, biota, bacteria and call our selves grand for living on a planet de-nuded of complexity– excepting ourselves. we will relish and celibrate our high intelligence.
    I would rather we humans figure out how to stop this sixth extinction event we find ourselves in (and resposible for). How to stop the main engines of this extinction event (it is not just global warming)
    One of the main drivers of this extinction event is commercial fishing, the main driver of ocean microplastic polution is not water bottles – it’s fishing nets and commercial gear – rapatious greed and an economic system hell bent on self destruction. We get the horsemen in charge of the levers of progress.
    In any event – we humans are the drivers and passengers on this planet who have had a relatively short time on this planet – during this time we are driving drunk, endangering the planet, fighting with eachother, killing our very mode of survival — all the while claiming we are civilized and intelligent – We are intelligent, we are capable of stopping this tragedy, I just wonder if we are civilized enough or smart enough or have enough common…common sense.
    Kelp and coral and the interconnected-ness of life is astounding
    Sorry- it’s just an outburst of impatience, frustration and weariness of all that could be done and all that is not

    1. drumlin woodchuckles

      Solving one problem does not philosophically preclude solving other problems too. And maybe solving one problem might even improve social morale and expand social imagination enough to make mass quantities of people newly upgraded and enabled to think of solving these other problems.

  12. DJG, Reality Czar

    An interesting observation: “Granted, I’m going all PoMo here, but this reminds me of academic politics, although some departments (***cough*** economics ***cough***) are no doubt far worse than others. Speculating freely, one might wonder whether these academics find predator-prey relations so powerful and illuminating as an analytical tool because they mirror the relationships that matter most to them in their professional lives. Department chairs, red in tooth and claw, as it were.”

    I recall in the 1960s and 1970s when the territoriality of birds was all the rage. Now, we don’t hear so much about how birds are territorial, and there has also been some diminution in stress on the territories of wolves. Instead, we are reading about the intelligence of birds and wolves–which means that territory is flexible and cooperation becomes more important. Yet for humans the end of colonization and the postcolonial wars were what preoccupied much of the 1960s and 1970s. So you have human behavior shifted to animals.

    An ancient story indeed. I’m thinking of Aesop.

    Likewise, the seepage of human preoccupations from discipline to discipline isn’t always productive. Besides apex predators and territoriality, delicate concepts, we now see “binary” applied to sexuality, when the concept originated in mathematics and its application, computer science. I suspect that the binary of computing isn’t really applicable to a wider world, but here we are. The irony here is that until binary was applied to sexuality, sexuality wasn’t thought of as “binary.” All one has to do is think of the many terms in the spoken language and do a little reading of the great psychologists.

  13. Verifyfirst

    Don’t forget kelp ( a sort of seaweed) and it’s cow methane eliminating properties…..

    Unfortunately, while there are many bright ideas out there that could reduce or eliminate global warming, they would have to be implemented immediately and at scale, which is not going to happen. Within 5 to 10 years, the feedback loops will be irreversibly engaged. So unless someone scales carbon extraction from the atmosphere within those 5 to 10 years, the great human die off will be upon us.

    In the meantime, it is of course a source of good entertainment to read about all the things we “could” do…..

  14. R

    My Irish in-laws have friends who moved to British Columbia to start a seaweed farm (grown from ropes anchored to buoys). The friends have since moved back to Ireland to start a similar venture off Donegal.

    I tried to find a link to their efforts but failed. I was however rewarded with a very detailed article on the Irish seaweed industry and some interesting integrated marine farming concepts in Ireland and North America.

  15. Gregory Etchason

    Yves, I’ve been taking Kelp 600mg (whole thallus) for 6 months. My joint pain has declined dramatically.
    I didn’t start it for joint pain but I’ll keep taking it because of it. I first noticed the effect after 2 months. I stopped and joint pain returned in two weeks. I haven’t required any NSAIDS since starting Kelp.

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