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The Future Of Food Is In The Sea

In the face of a warming world, the fields and forests of the sea, aka seaweed, may well be the key to feeding a hungry population while combating climate change in the bargain. Here certifiable Venezuelan dive geek, Carlos Lander, explains why we may want to put seaweed on the menu. Side of kelp with those veggie burgers?



by Carlos Lander. Lead image courtesy of Jason Brown,

🎶🎶 Predive Clicklist Seaweed by Tindersticks

There is a deserved urgency in climate change discussions, but we might discover a key piece of the puzzle in a diving domain—the ocean. Our seas contain a unique ecosystem that harbors countless secrets we are only beginning to understand. Can one of those secrets save the planet?

If you ever dived into a tangle of seaweed and watched with fascination as the undulating waves cradled and carried the sea grasses with magical ease, it probably did not occur to you that this underwater forest could hold the key to slowing climate change—and so much more. Let’s dive in and examine the possibilities.

Seaweed’s Culinary Past: A Short Selection

Seaweed is not a weed at all—it’s a loosely-defined group of both prokaryotes (e.g. sea grasses) and eukaryotes (e.g. algae, microalgae) that occupy both marine and freshwater environments. Seaweed grows in oceans, lakes, and rivers, and algaes alone represent 16,000 species

When we think of seaweed consumption, some think of Asia’s seaweed salads and sushi rolls. But, seaweed consumption is a centuries-old tradition throughout the globe.

The Americas

The use of algae in the pre-colonial Americas has been overlooked, perhaps due to colonial destruction of Mesoamericans’ written documents.

Today we call algae spirulina; however, the Aztecs1 collected a bluish-colored mud called “tecuitlatl,” which roughly translates to “poop rock.” In bloom seasons, they filled entire canoes with it, drying the macroalgae under the sun and using the final product to make tortillas. Spanish conquistadors reported that they tasted like cheese. 

Curiously, in Venezuela2, native people once used an algae-based degreasing paste and included algae in their clay pottery  mixes to increase cohesion, eliminate bacteria, and provide elasticity to the clay during the curing process. 

In Chile, seaweed has been widely consumed since pre-colonial eras. This tradition spread gradually from the coastal (Indigenous) people to the cuisine of the colonists, perhaps due to ease of transportation and preservation. To harvest the seaweed, they cut it by the stalkipe and waited for the current to wash it onto the beaches3. After the drying process, the products were sold at the market.

The most widely eaten seaweed by the First Nations along the northwest coast of North America was red laver. These vitamin- and mineral-rich algae  were popular particularly in times of famine and food shortages. They dried or fermented the seaweed and processed it into cakes, pounded it and stored it in small flakes ready to be eaten as snacks, or cooked it in soups and stews.

Algae dish. Photo courtesy of Maria Fernanda Capecchi 

Another interesting example, but this time from the northeast coast, is Native Americans’ use of seaweed in place of salt brought by colonists. They also used seaweed for storage and food preparation; for example, they layered algae on the heated stones in pit cooking, which protected the food from being overcooked and avoided contamination from sand. This provided a distinct flavor, as well.

1 Chronicles of Missioners Francisco Hernandez Y Fray Toribio de Benavente. Spirulina is a non-differentiated filamentous cyanobacteria common in alkaline lakes and it is cultivated in lakes.
2 Archaeological Chronicle of Venezuela
3 Seaweed Consumption in the Americas, Jose Luis Perez_llorens

Europe and the Middle East

Europeans in the Middle Ages burned algae to extract salt—a practice that continued in France until 1950.

In 1940, the French phytologist Pierre Dangeard4 described that, in Lake Chad (lying in portions of today’s Cameroon, Chad, Niger, and Nigeria), the Kanem people produced a salty, algae-based cake. Scientists continued to discover cultures spanning the deep Sahara Desert5 to the Red Sea that also prepared similar biscuits from algae.

A Worldwide Phenomenon

Archaeological and ethnohistorical data proposed a cross-cultural adoption of seaweed as food. Icelanders brought the tradition to North America, and other migratory movements proliferated the practice. 

The tradition of eating seaweed declined with colonial development, but in the mid-19th century the migratory movement to North America from Irish, Scottish, and Asian populations re-introduced seaweed to the local gastronomy, which still informs today’s restaurant industry; more about this later.  

4 Linnaean Society of Bordeaux Magazine
5 Belgian expedition led by the biologist Leonard, see: Paniagua-Michael J, Dujardin E, Sironval C 2004. Aztecan’s Chronical.

Photo courtesy of Jason Brown

The forest of the sea can save us all: The role of seaweed in climate change

Climate change discussions are commonly dominated by three topics: clean energy, reduced greenhouse emissions, and carbon dioxide extraction  from the atmosphere. Economically speaking, removing huge amounts of CO2 from circulation has become a price that society must pay.

Let’s zoom out to the global economy. Many countries with lower GDPs currently rely on fossil energy—it’s still not cost-effective to implement 100% fossil-free energy at scale, especially for governments that simply don’t have the capital to invest in alternative energy infrastructure. Instead of sanctioning countries that can’t afford to go green, CO2  removal technologies could address some climate change issues without punishing late adoptees of fossil-free philosophy.

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In a world where seaweed farms already exist, we have a cost-effective, scaled mechanism for growing the crop while reaping the benefits of plant-based carbon capture. 

The ocean is the biggest surface on the planet, and it’s a key climate regulator—it stores and transports heat, carbon, nutrients, and water all around the world. Theoretically, we can develop a climate-altering-crop6. Macroalgae already has a place in our culture, and the pharmaceutical, agriculture, and food industries are already harnessing its unbelievable genetic diversity. 

Collecting algae. Photo courtesy of Maria Fernanda Capecchi 

Seaweeds in general are among the top carbon-capturing organisms and actually perform much more efficiently than trees. Seaweeds’ symbiotic relationships with bacteria reduce photosynthetic waste, and algae uses its entire surface area to photosynthesize. Seaweed grows fast and is economically viable.

Given the massive ocean surface, there is a potential opportunity for offshore marine farms to enhance natural production. Seaweeds require minimal nutrients, they grow year-round, and scientists continue to develop new ways to use and synthesize algae.

Although it is possible that mass production of algae could have a positive effect on global warming—since it could potentially absorb gigatons of atmospheric CO2—it is unclear exactly how an effort like this could affect deep sea marine creatures. But, successful permaculture seaweed farms already exist among thriving fish and shellfish populations. Seaweed is an ideal permaculture crop, it reduces water’s acidity, and it supports an ideal environment for larvae and juvenile marine life. Seaweed farms, while in their infancy, promise to be a multibillion-dollar industry supplying pharmaceuticals, textiles, and (interestingly) food production.

6 Tim Flannery

Seaweed as food

There are three edible algae suitable for aquaculture—red, green, and brown algae. 

Fish and algae. Photo courtesy of Maria Fernanda Capecchi 

Red algae

Sheets of red algae are commonly sold as nori.

Nori is cultivated in cold and shallow marine waters, where it is collected and sold for use in various products. You’ve likely encountered it as the “paper” employed to wrap sushi. You can buy it at the supermarket in sheets or in a dehydrated, wrinkled form. Red algae offers substantial nutritional value, featuring significant iodine, manganese, as well as vitamins A, B2, B9, and C.

Red algae alternative. Photo courtesy of Maria Fernanda Capecchi 

Another common red algae product, Irish moss or carrageen moss, has a foothold in the food industry. By weight, carrageen mosses comprise  nearly 10% protein and about 15% mineral matter;  they are also rich in iodine and sulfur. The food industry commonly uses it as a thickener and stabilizer in milk products and other processed foods, and it can even be used in beer brewing.

Carrageen moss is found in abundance in the Atlantic Ocean.

Brown algae

Wakame, or sea mustard, is a highly nutritious species of kelp farmed on the coasts of the Indo-Pacific Ocean. It has a strong flavor with slightly sweetened touch. It is most often used in soups and salads.

Kelp (Laminaria) has many uses: It’s used in toothpastes, shampoos, salad dressings, puddings, cakes, dairy products, frozen foods, pharmaceuticals, and fertilizers.

In addition to the iodine and iron generally found in all marine algae, brown algae offer calcium, folate, magnesium, and vitamin K. Recent studies suggest that vanadium and fucoxanthin, substances present in brown algae, help to control diabetes via blood sugar regulation and increased production of omega-3  (though they are found in small quantities in the algae). 

Green algae

Sea lettuce, sea palm, and sea grapes are the most common green algae, they are rich in beta carotene and collagen. While the data is new, green algae may offer anti-tumor properties in cancer prevention applications. Green algae are commonly commercially harvested  in lakes and ponds.

Miscellaneous algae applications

  • Researchers recently used blue-green algae to successfully power a computer’s microprocessor for longer than six months. Their findings could revolutionize the energy supply for the Internet of Things—the network of physical devices that facilitates the web. 
  • Although still in their infancy—and not yet cost-effective at scale—several government agencies (including the US Department of Energy) and companies are funding research and development programs to produce biofuel from algaes in the face of rising fossil fuel costs. 
  • Biofuels composed of 40% algae have been used on test flights in jet applications.
  • Microalgae are a present consideration for wastewater treatment applications—they have the potential to decrease nitric and phosphoric qualities of treated wastewater.

Algal bloom concerns

Algal bloom can be very hazardous for the environment and local economies; these blooms are mainly composed of cyanobacteria, a blue-green algae variety that can leach the water of oxygen and produce toxic chemicals lethal to zooplankton, fish, and other water dwellers.

Climate change has produced warmer water temperatures and prolonged droughts. Blooms are more common under these conditions (especially drought ,which increases water salinity) .

Photo courtesy of Jason Brown


The ocean holds immense resources and potential for future generations of innovators—culinary experts and climate scientists alike. 

Perhaps a quintessential example of underwater innovation is Nemo’s Garden, an experimental agricultural operation growing terrestrial plants under the sea.

Marine and freshwater algae could be a key piece in the climate change puzzle. It has the potential to extract gigatons of CO2 from the atmosphere when farmed at scale. But, if we cultivate it in deep marine trenches, the potential effects on these ecosystems are still unclear. However, seaweed still shows promise as a permaculture crop. We may only learn more via trial and error.

In the interest of scale, a global seaweed production effort must accommodate even countries with low GDP—on both a governmental and community level. It could provide economic opportunity for investment in sustainable energy, decreasing the incidence of future fossil fuel burning. But, this effort requires global advocacy and up-front financial investment.

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The pharmaceutical and biofuel industries are already harnessing inland cultivation of freshwater algae, introducing new applications every day. 

The combination of seaweed’s potential environmental power and the precedent of algae consumption throughout history create an excellent opportunity for both ecological innovation and culinary education. 

Ultimately, the introduction of seaweed as a climate change solution must be equal parts global effort, scientific enterprise, political project, and social endeavor.

Thanks to Maria Fernanda Capecchi and Luis Lemonie for research assistance..Maria is a biologist dedicated to algae in all aspects from farming to cuisine. Luis is an archeologist that shares my passion for scrutinizing the human past.

Thanks also to InDEPTH editor Nic Haylett, whose extraordinary editing skills helped to organize and clarify much of this important work. Finally, we’d like to offer thanks to tech entrepreneur Joe Howell for encouraging us to explore the importance of sustainable ocean food sources.

Dive Deeper

zme science: Onshore algae farms could feed much of the world while reducing the environmental impactby Fermin KoopIt’s a promising new type of farming—but there are many hurdles in the way.

BBC: The plans for giant seaweed farms in European waters

NSW GOV: New opportunities to support and harness underwater forests

PubMed Central: Microalgae, old sustainable food and fashion nutraceuticals

NYT: The Johnny Appleseed of Sugar Kelp

The Power of Kelp  

What is the Blue revolution?  

DIY Regenerative Oceans  

Nemo’s Garden

World Ag collapse 

GZERO Media: Introducing GZERO’s Coverage on Hunger Pains: The Growing Global Food Crisis  

Carlos Lander—is a father, a husband, and a diver. A student of economics, he’s a self-taught amateur archaeologist, programmer, and statistician. In his view, the amateur brings a unique mindset to the table and, paired with expertise from professionals, can discover advantages in the field. I studied economics at university. My website is Dive Immersion.

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Why It’s Okay To Make Mistakes

To err is human. To trimix is divine? Instructor evaluator Guy Shockey examines the importance of learning through one’s mistakes, and most important, being willing to admit and share them with others, especially for those in leadership positions. It’s the only way to create ‘psychological safety” within our community and improve our collective diving safety and performance. Wouldn’t that be divine?




By Guy Shockey. Images by Andrea Petersen

A few months back, I read an article about a club where members talked about failure and making mistakes. This club required that members freely discuss their mistakes and failures without fear of judgment. The goal was to destigmatize failure and recognize that we learn by making the very mistakes we are afraid to talk about! Moreover, to become truly high performing and develop unique and creative solutions to problems, the article argued that we needed to be free of the worry of failing—to understand that “to err is human.” 

The article went on to mention that for high performing teams to be successful, they needed to operate in an environment of “psychological safety.” This term was originally coined by Harvard professor Amy Edmondson, and Gareth Lock has written about the concept extensively. In his work with The Human Diver, Lock identifies psychological safety as a key component primarily missing in our diving culture. As a full-time diving professional and someone who delivers The Human Diver programs, I couldn’t help but reflect on the failure-destigmatizing club in the context of our diving culture in general and, more specifically, dive training.

Consider the humble Roomba robot vacuum cleaner. The Roomba learns how to clean a room by bumping into nearly everything in the room and, with some nifty software, creates a “map” of all the “vacuumable” space in the room. Then, it goes about its business efficiently and repetitively cleaning the room. The Roomba has learned by making multiple mistakes—much like humans do. 

Now imagine being able to transfer that new “map” from one Roomba to another so a new Roomba doesn’t have to repeat the mistakes of the first as it sets out to vacuum the room. Finally, imagine this transfer of data to be less-than-perfect—perhaps, occasionally, the new Roomba will make some mistakes (from which it will learn). But it will make far fewer mistakes than the original Roomba had to make. 

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I’m sure you can see where I’m going with this. Humans learn the same way Roomba vacuums do (hopefully without running into as many hard surfaces), and we can transfer information between each other. Because the transfer process is less than perfect, we still make some of the same old mistakes. This is particularly interesting because, despite drawing specific and repeated attention to these common errors, students often still make the same errors! One of the most important parts of instructor training is educating future instructors to recognize where these common mistakes will occur and encouraging them to ramp up to being hyper-vigilant rather than regular-vigilant. 

Learning Through Mistakes

One way we learn is by making mistakes, talking about them, and sharing the experience in the hopes that future divers don’t have to make the same ones. At its core, this is the very essence of learning. Incidentally, this is also what makes experience such an important characteristic of a good teacher. The more experience the educator has, the more mistakes they’ve made and, consequently, the more information they can transfer. Fear of owning our mistakes keeps us from learning from them; perhaps more importantly, it means that others will miss out on these important lessons. 

Yet, in diving culture, we (for the most part) shy away from discussing the mistakes and errors we (hopefully) learned from for fear of being considered a less than capable diver. When divers in influential or leadership roles do this, it is a tremendous loss for the diving community in general—it robs future groups of divers of the opportunity to learn. Sadly, because this commonly happens at the leadership level, it is hardly surprising that other divers further down the line copy that behavior, and we ultimately end up with a diving culture that emulates the example of the leadership. 

I advocate for taking the opposite approach. In my teaching, I am very open about the mistakes or errors I have made while diving. I recognize that I am basically a smart Roomba, and I learn by making mistakes. Thus, it would be disingenuous to pretend that I don’t make mistakes—I had to learn somewhere! I believe this approach lends authenticity to my instruction and starts to create psychological safety in my classes. Ultimately, my goal is to encourage students to recognize that, “If the instructor can admit they make mistakes, then it is okay to talk about the ones our team made during the training dive.” 

I have found that there is a remarkable change in the relationship between student and instructor when this happens. Learning becomes more of a collegial activity, and stress and performance anxiety significantly decrease. This leads to more successful learning outcomes and happier students. I am a firm believer that, while training can be serious, it should also be fun!

Creating Psychological Safety

Creating psychological safety in our diving culture is a daunting task, but every flood begins with a single raindrop. The first thing that needs to happen—at all levels—is an acknowledgement of failures and mistakes among  those in positions of influence and leadership. Sadly, this is not as easy as it sounds, and there is frequent pushback. Ego is one of the most dangerous aspects of a personality and it frequently causes people to overreach, crippling growth and learning. The irony here is that every single one of us has made a mistake. We all understand that no one is perfect, yet many in leadership positions cling to the view that vulnerability is weakness—that demonstrating imperfection will cause others to stop trusting them (or revering them). 

I propose that the opposite is true. I should also note that I believe every dive professional is acting in a leadership role. This means that, while creating psychological safety can best be started by those in senior leadership roles, it must also be encouraged at all levels of leadership, including anyone in supervisory or teaching roles. In a perfect world, every diver would embrace this approach and enable psychological safety within their team.

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There are a few things you can do to help develop psychological safety. First, facilitate a debrief at the end of the dive and begin with “something that I as the leader did wrong or could have done better was…” This immediately creates fertile soil for psychological safety to flourish. When the leader is the first person to say, “I made a mistake,” it establishes that this is a safe place to discuss mistakes and errors with the intention of learning from them. This opens the door to follow-up discussions. 

On the subject of transparency, in any organization it is often the voice of dissent—a contrary position—that is the most valuable. This voice causes the group to reflect on original assumptions and decisions and offer a perspective that “groupthink” does not. This means that we need to be open to different solutions to problems lest we be blinded by our own cognitive biases—ones that have been developed over thousands of years of evolution in order to make us more efficient Roombas. 

We are essentially fighting against our own brains, and it takes a significant amount of effort to think outside the box. We are hard-wired to think in terms of “evolutionary” rather than “revolutionary” ideas, and we need to make a conscious effort to consider the voice of dissent and understand why it is so hard to do so. 

In Conclusion

In psychologically safe environments, we experience a significant increase in “discretionary effort,” or shifts on the “need to do” and the “want to do” curves. If a team has a high degree of psychological safety, they are motivated to perform higher than the minimum standard. If you create a high degree of psychological safety, your team will perform better as a result. 

This is where it all comes full circle. We want our dive teams to perform at a high level. We want them to have a high degree of discretionary effort. We want them to embrace our “commitment to excellence.” Therefore, we must be the ones to create the psychological safety necessary to facilitate this growth. 

One of the most effective things you can do as a leader is to be open and willing to share that, in the end, you are human too. You make mistakes, you admit to them, you learn from them, and you share them with others so they can learn too.

One of the most effective things you can do as a leader is to be open and willing to share that, in the end, you are human too. You make mistakes, you admit to them, you learn from them, and you share them with others so they can learn too.


Other stories by Guy Shockey:

InDEPTH: Reflections on Twenty Years of Excellence: Holding The Line (2019)

InDEPTH: Situational Awareness and Decision Making in Diving (2020)

InDEPTH: The Flexibility of Standard Operating Procedures (2021)

InDEPTH: How to Become an Explorer: Passion, Partnership, and Exploration (2022)

InDEPTH: Errors In Diving Can Be Useful For Learning— ‘Human Error’ Is Not! by Gareth Lock

InDEPTH: Learning from Others’ Mistakes: The Power of Context-Rich “Second” Stories by Gareth Lock

Guy Shockey is a GUE instructor and instructor trainer who is actively involved in mentoring the next generation of GUE divers. He started diving in 1982 in a cold mountain lake in Alberta, Canada. Since then, he has logged somewhere close to 8,000 dives in most of the world’s oceans. He is a passionate technical diver with a particular interest in deeper ocean wreck diving. He is a former military officer and professional hunter with both bachelor’s and master’s degrees in political science. He is also an entrepreneur with several successful startup companies to his credit.

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