Entangled Encounters with Cheonggak

Daniel Duarte Pereira

The names of seaweed

At Ramalha Beach, near the small village of Apúlia in Portugal, my 2-year-old niece, Laura, was looking with curiosity at the marine life in the intertidal ponds. It’s 10:00 in the morning in early September 2023, and the tide is at its lowest due to a super full moon. Among the tidal rocks, she discovers a type of seaweed with a fascinating shape. Instead of resembling a typical terrestrial plant, its leaves (if we can call them that) took on a cylindrical blade-like form, much like thick spaghetti. Laura picked up a frond of this seaweed and examined its texture, shape, and weight. I stood beside her and explained that in Portuguese this specimen is named Chorão-do-mar, which translates to "Sea Weeper" in English. Laura found the name curious. "Why is it called that?" she may have wondered. "Does it really weep? And what would it be weeping about?" She looked at me and proposed that we change the name to Cabelos-do-Mar, which means "Hair of the Sea" in English. To illustrate her point, she placed the picked Chorão-do-mar above her head, as if it were a wig. “See, it should be called Cabelos-do-Mar”, she insisted.

© Image by the author. Ramalha beach, Portugal.

Laura's casual encounter with seaweed highlights an intriguing aspect of our relationship with phycological ecosystems. Unlike terrestrial species, marine species, particularly seaweed, remain largely unfamiliar, especially in Western cultures. They often appear as enigmatic life forms, open to imaginative interpretations, such as linking them to terrestrial objects and even suggesting new names.

Seaweed unveils itself to us only twice a day, and only for a brief period when the tides recede. For subtidal species like Chorão-do-Mar, this revelation occurs during spring tides, particularly when triggered by a full moon. Within this dynamic interplay of seeing and not seeing, of encounter and non-encounter, there are only a few fleeting opportunities to meet these marine species. For most of the time, seaweed remains submerged in water, concealed from the human gaze, and accessible solely through human imagination.

Chorão-do-Mar, Algue chou-fleur, Spúinse, Chonggak, Cì song, Miru, Green Sponge Fingers, Green Sea Fingers, Velvet Horns, Dead-man’s Fingers, Oyster Thief, Green Sea Velvet, Fleece, Sponge Tang,1 are all distinct names, originating from various languages and geographic regions, that refer to the same family of seaweed: Codium. Beyond the differences in language and culture, what unites all these common names is their association with the seaweed's physical attributes, such as its velvety and spongy texture or its finger-like form. These diverse names, emerging from different languages and cultures, offer us a glimpse into the types of connections that these communities have with their marine ecosystems.

Song of the Wind

During my involvement in the Song of the Wind art residency in the Republic of Korea, I had the privilege of fully immersing myself in the Dangmok-do village, situated on the remote island of Yaksan-myeon, Wando-gun, which is a part of South Jeolla Province. Motivated by the fascination surrounding seaweed, I set out to investigate the cultural relationship between the local community and the phycological ecosystems in the region where I would be residing for a month.

The Republic of Korea stands as one of the world's foremost producers and consumers of seaweed in the world,2 cultivating extensive seaweed farms around the approximately 2,000 islands that dot the coastal region of South Jeolla Province. Starting in the 1970s, when the Korean government began investing in this venture, seaweed farming experienced a substantial boom, leaving a profound impact on the social and economic fabric of these communities and significantly transforming the sea-land-scape.


Korean seaweed farmers cultivate various types of seaweed, including Dasima (Saccharina japonica), Miyok (Undaria pinnatifida), and Kim (Pyropia complex). However, during my stay in Yaksan-myeon in September 2023, the seaweed harvesting season had already concluded. The remnants of seaweed farming could only be seen in the numerous buoys floating on the sea and the large, bright green mats where Dasima had been drying a few months earlier.

© Image by the author. Bagging Chonggak, Dangmok, Korea.

While exploring the streets of Dangmok, I came across a medium-sized warehouse with its large metal doors wide open. Inside, I observed a group of workers squatting down, diligently bagging what appeared to be dried seaweed. Intrigued, I stepped in and attempted to engage with them, utilizing a voice translation app to inquire about the type of seaweed they were handling. When seaweed is dried, it can be challenging to identify the specific species. After a bit of back-and-forth translation, I learned that this seaweed was called Cheonggak, which roughly translates to "green antlers" in English. A quick online search later confirmed that “Cheonggak seaweed” is, in fact, Codium, the very same type of seaweed that my niece, Laura, had picked in the intertidal ponds of Portugal just a few weeks prior.

My two personal encounters with Codium, both in Portugal and in Korea, underscored the significant role this type of seaweed would play during my stay in Korea. It became evident that Codium would serve as a focal point for my research, enabling me to grasp the socio-spatial characteristics of the region and facilitating my engagement with the local community.

I became obsessed with Cheonggak, meticulously tracing its journey from the sea farms to the inland facilities where it was dried, processed, and packaged before entering the market. As part of my methodology, I chose seaweed pressing, a technique I had already been exploring as part of my doctoral research, as a research tool to forge connections with the local community and uncover cultural narratives, including popular stories, recipes, and rituals that were associated with this specific type of seaweed.


Being an amateur seaweed enthusiast in Portugal, my journey with Cheonggak in Korea initially began with the intention of exploring seaweed in its natural habitat among the intertidal rocks. After some initial research, which included studying aerial views online, I decided to explore the rocky shores near Dangmok during the low tides.

© Image by the author. Dangmok, Korea.

To my surprise, I found no signs of Cheonggak, and the diverse array of seaweeds I had expected to see were absent. What I did come across in these intertidal zones were discarded waste materials and garbage. This included items like buoys, styrofoam, and ropes that had washed ashore from the nearby seaweed farms. While seaweed farming is renowned for its potential ecological advantages, such as carbon sequestration and water quality improvement,3 it was clear that the presence of plastic waste in these waters was an undeniable drawback.

The absence of Cheonggak in the intertidal zones near Dangmok could be attributed to the fact that September in Korea marks a transition period from warm to cold waters when mature seaweed specimens give way to new ones that will grow in the upcoming winter months. My expectation of a natural habitat flourishing with seaweed was instead replaced by the remnants of an intensive activity such as seaweed farming that was responsible for producing and supplying Cheonggak to Korean markets and dishes. If I wanted to follow the traces of Cheonggak, I would have to do it through the production chain and not its natural habitat.

The Oyster Thief

On the second week of my artist residency, my fellow resident, Wan Chantavilasvong, and I arranged a guided tour to explore the abalone aquaculture farms. We were accompanied by the president of the local seaweed and abalone farming association, who took us by boat to his own farm. The abalone farms consist of rectangular platforms on the sea, each featuring multiple square pools with nets where abalones grow. To keep these structures afloat, they are supported by numerous styrofoam buoys, that were anchored to the seabed using weights and ropes, to guarantee its stability and position in the sea. While Wan dived into the abalone pools to take underwater pictures, I walked above the platform and noticed several Cheonggak specimens attached to the ropes, nets, and buoys. At the same time, our tour guide was lying down on the platform with his arm on the water, as if he were trying to reach something below. A few minutes later, he retrieved a massive oyster, which he referred to as “king-size”.

© Image by the author. Abalone farmer picking a King-size Oyster.

This unexpected encounter between Cheonggak and oysters brought to mind one of the English names given to Codium seaweed: Oyster Thief.

Codium fragile, one specific species from the Codium type, is recognized as a native species from Japan and the North Pacific. Its presence in the Atlantic was first documented in Northern Ireland in 1845. Due to the increase in global marine traffic and being transported daily in the ballast water of ships across the globe,4 this species spread across Europe, the east coast of America, the northeast Pacific, and Australasia, being considered one of the most rapidly spreading invasive species of seaweed from the last century.5 While it is viewed as a culinary delicacy in Korea that is included in some types of kimchi, in other parts of the world, it is regarded as an invasive species and an ecosystem engineer because of its ability to modify the environment it occupies and significantly impact other native species.

Although the origin of the name is unclear, when Codium fragile arrived in the northern Atlantic, some English-speaking coastal communities started calling it the “Oyster Thief” as it grew on and around oyster beds, encroaching on the oysters' habitat, inhibiting their growth, and potentially causing harm to its population.6 Therefore, the nickname “Oyster Thief” underscores its association with oyster farms and its potential to disrupt and influence oyster farming operations.

After having a pleasant ocean taste from eating the King Size Oyster, I picked some Cheonggak specimens attached to the platform and initiated, later that afternoon, into trials of seaweed pressing and cyanotypes. While doing this, I wondered if the “Oyster Thief” name for Codium would resonate somehow with the oyster producers in South Korea. 


I shared with our curator, Sunyoung Oh, the desire to conduct a seaweed pressing workshop with the community. She arranged for me a date, a place, and a group of youngsters from Wando to do it. However, the amount of seaweed we had collected during the abalone tour was insufficient for this, so in the following days, I began my search for a local Cheonggak producer who could harvest it fresh from the sea farms and deliver it to me on land.

© Image by the author. Edi’s seaweed warehouse.

This led me to meet one producer from Dangmok named Edi. I met him when he was drying Cheonggak in a large dehydration room he had built within his business warehouse. After he kindly offered me a cup of coffee, Edi explained that Cheonggak has the specificity of having a high-water content, making up nearly 80% to 90% of its composition. This fact made me think that this might be the reason why this seaweed is named Chorão-do-mar, "Sea Weeper" in Portugal. Despite its relatively small size, compared to other farmed seaweed varieties, Cheonggak has a slow growth rate and takes longer to dry than other types of seaweed.

Edi's dehydration machine was built in one corner of the warehouse, composed of a chamber measuring 4 meters by 4 meters and a standing height of 2.5 meters. Given the warehouse's ample vertical space, they utilized the area above the chamber, accessible via a side metal staircase, as an office to support their business operations. The base of the dehydration chamber was raised about 50 centimeters off the ground and featured a metal mesh on top where they placed the fresh seaweed for drying. All the necessary infrastructure and machinery responsible for blowing hot air upwards to dry the seaweeds were concealed beneath this mesh. To enclose the chamber during operation, Edi used opaque curtains.

Before the availability of drying machines, harvesters would dry seaweed in the open air, manually flipping it every day for several days until it dried completely. This labor-intensive process is still used for Dasima due to its large size and quantity. During June and July, Dasima seaweed covers the nearby fields with a synthetic mat, altering the landscape from a bright green (the color of the mats) to a dark brown (the color of Dasima). Despite our perception of seaweed farming as a marine activity, it requires a significant amount of land to manage the preparation process after the harvesting and before it enters the market. With the arrival of dehydration machines in Wando, the reliance on sun-drying structures decreased, and the drying process for Cheonggak, which used to take a few days and be physically demanding, was reduced to just a few hours, with less labor involved.

Edi agreed to bring me a fresh Cheonggak seaweed frond the next time he sailed to his seaweed farms.

Sea Farms

A few days after my encounter with Edi, our curator organised a boat trip with a local seaweed farmer from Eodu-ri village. The purpose was to allow Wan to capture underwater photographs of the Cheonggak farms. I seized this opportunity to swim amidst the farms, closely observe the farming system, and harvest fresh Cheonggak for an upcoming seaweed pressing workshop.

© Image by Sunyoung Oh. Cheoongak farms.

Despite a gentle current that required constant swimming, the sea was remarkably calm, with no waves or turbulence. This peaceful sea condition in the region is possibly due to the presence of numerous islands that act as natural barriers, shielding the area from rough waves and strong currents and creating an ideal environment for seaweed farming.

To cultivate seaweed in the sea, farmers employ a technical system that replicates the natural conditions necessary for seaweed growth, such as tides, providing a solid attachment structure, and ensuring shallow waters for sunlight penetration. In the case of Cheonggak farms, this system uses long ropes, approximately 100 meters in length, to which the seaweed attaches. Buoys suspend these ropes in a linear arrangement and at the precise depth required for seaweed growth. Hundreds of ropes with this same setup are placed parallel to each other, creating geometric patterns in the sea, similar to agricultural plots on land.

Another aspect of seaweed farming involves understanding the reproductive cycle. Different types of seaweed have specific reproductive processes that influence the farming system. Most seaweed varieties go through a seeding process in a nursery environment. The resulting seedlings are later attached to ropes and placed in the sea, where they grow and mature until they are ready for harvest. However, Cheonggak is unique in that it doesn't require this artificial nursery process, as it naturally propagates by seeding directly on ropes placed in the sea.

Cheonggak farming is a year-round endeavor, with seeding taking place in late October when the water starts to cool, and harvested in July or August of the next year. For those farmers willing to take the risk and aim for higher profits, they can continue harvesting until late December to sell the freshly harvested Cheonggak at better prices in the markets. This was the case of the farm we visited.


All these small encounters looking for Cheonggak enabled me to collect a good supply to proceed with the seaweed pressing workshop. The time had arrived to explore what kinds of stories and reactions this tool could enact.

© Image by the author. Seaweed pressing workshop wirh youngsters from Wando, Republic of Korea.

The practice of collecting seaweed has a rich historical lineage dating back to at least the 17thcentury in Europe, driven by a burgeoning fascination with natural history and specimen collection. Over time, numerous universities and natural history archives have diligently preserved these pressed seaweed specimens, not solely for their visually intriguing qualities but to support scientific research on phycological ecosystems. In the contemporary era, hundreds of seaweed herbariums exist worldwide, with scientists actively engaging in the exchange and trade of various species of pressed seaweed to enhance their collections and further their research endeavors.

But pressed seaweed can show us more than just a mere preserved biological specimen; it may act as a medium to reveal the environmental and cultural contexts of that specimen. In her essay titled “The Media of Seaweed: Between Kelp Forest and Archive”,7 Melody Jue argues that the chemical processes of desalination, dehydration, and saturation that take place in making pressed seaweed work as a “photographic negative”, that might help us to understand the specific environments in which the seaweed might have flourished.

Similarly, but from a social perspective, Ann Garascia illustrates how the seaweed cyanotypes produced by photographer and biologist Anna Atkins in the late 19th century serve as a support to stimulate “lively connective tissues among texts, humans, and environmental agents,”8 rather than just reinforcing the human dominance over nature. Garascia appropriates the term “autobotanography” to suggest that the “lively connective tissues” that Anna Atkins’ cyanotypes bring together, expose a shared history of archiving practices that involved women, plants, and the local natural and cultural environment of the time.

These two authors helped me to reframe my purpose for the seaweed pressing workshop, as I aimed to broaden the scope of seaweed pressing beyond its purely techno-scientific realm to work as a medium that reveals personal narratives, aspirations, and cultural settings; this can unveil the intricate and interconnected relationships between humans, seaweed, and the environment.

Two seaweed pressing workshops were devised. The first one, titled “Entangled Encounters with Seaweed”, was held with 16 youngsters from Seokchiri, Gegeum-myeon, in Wando-gun. The second, conducted in collaboration with fellow Filipino resident artist Ezekiel Sales, drew inspiration from his interactions with Filipino seaweed migrant workers during his fieldwork on Geumil Island. This second workshop was entitled “Seasonal Labor and the Migrations of Seaweed”, and happened at the temporary residence of these Filipino migrant workers.

For both workshops, I brought along a box filled with Cheonggak, a ream of watercolor paper that I had cut into postcard-sized pieces, and a seaweed presser made from square pieces of plywood, which I had cut and purchased in Wando-do.

I set up all these materials on a table and instructed each participant to create two seaweed postcards. One postcard was meant for them to keep as a memento, and the other was intended to be sent to someone around the world who had made significant contributions and reflections on human interactions with seaweed, such as artists, academics, seaweed harvesters, or scientists. In the case of the workshop with Filipino migrants, the postcards were addressed to their families back home in the Philippines, and artist Ezekiel Sales would deliver them personally once he returned home.

On the front of the postcard, participants were asked to introduce themselves, by providing their name and age, and the seaweed they were pressing, using its local name, which, in this case, was Cheonggak, and optionally, suggesting an alternative name for the species if they felt it resembled something else.

On the back of the postcard, participants had the freedom to leave a message and to share a personal story of their encounter with Cheonggak. This message could be a recipe, a poem, a drawing, or any kind of thought.

Do you know seaweed?

Just as Melodie Jue views pressed seaweed as a photographic negative of its origin environment and Ann Garascia interprets Anna Atkins' cyanotypes as an entangled space that connects autobiography and botany, I will try to analyze the pressed seaweed postcards produced in the workshops through the same lens.

During the workshop, some participants approached Cheonggak with a scientific perspective by displaying the specimen on the postcard in a clear and structured manner. Others took a more artistic approach, arranging the pieces in a way that captured the fluid, lively movement of seaweed when in the sea. The number of specimens on each postcard varied, featuring either a single branch or multiple branches. Some participants covered the surface of the postcard completely, while others took a minimalist approach with small, simple pieces.

Most participants speculated that their messages were intended for recipients unfamiliar with seaweed. They often initiated their messages with questions like “Do you know seaweed?” or “Do you like seaweed?” followed by a brief introduction to what Chonggak was and personal opinions on its taste, its health benefits, its significance for the Wando region, and its application to foods such as kimchi.

Interestingly, due to my Portuguese nationality, a few youngsters who were football fans addressed their postcards to the Portuguese football player Cristiano Ronaldo, emphasizing the benefits of eating seaweed to enhance his future success in championships.

In the second workshop, the Filipino migrant workers conveyed their messages to their families back home, introducing Cheonggak as the reason for their migration, to improve their families' financial situation. These specific messages unveiled the intricate connections between migration, displacement, labor, the economy, seaweed, and its ecosystems.

Chonggak keeper

As the keeper of the postcards, I was responsible for the drying process, which spanned the next week and a half. Each day for that period, I would open the press to check if the Cheonggak was drying properly and replace the humid newspaper sheets with new dry ones. Simultaneously, I selected and collected the addresses of personalities to whom I would send the postcards. Some recipients were people with whom I was familiar or acquainted, while others were newfound friends I had learned about during my research.

© Image by the author. Shiping pressed seaweeds from the workshop. Seul, Republic of Korea.

Additionally, I invited Wan to participate in this project by sharing one of the underwater pictures of the Cheonggak farms she had taken during our sea tour. These items were enclosed in translucent envelopes so that the pressed seaweed and the message it carried could be read by various individuals who encountered the post during its journey to its destination.

The interplay of various elements placed into a postcard, including the seaweed itself, the pressing process, the postcard format, the workshop's location, the ages and agency of the participants, my presence as a foreigner, and more, all contributed to unveiling the hidden layers and systems of interconnectedness in which this particular type of seaweed is immersed.

We anticipate that recipients from these communities will reciprocate by pressing seaweed from their own regions and sending it back to the young participants in Wando or elsewhere, thus nurturing a continuous exchange of seaweed specimens and their stories. This will, in turn, foster connections among diverse seaweed communities across varying geographical regions.

My personal experience and research with Cheonggak in Wando, the seaweed pressing workshops, and the distribution of the postcards are not intended to be a simple output of the residency but, rather, an open-ended project that may lead to further dialogues with seaweed communities and enthusiasts worldwide, nurturing an Entangled Encounter of Seaweed.

Picture by Liliana Fontoura
Daniel Duarte Pereira is a Portuguese architect trained at the School of Architecture, Art and Design of the University of Minho (EAAD) in Guimarães, Portugal (2011), where he worked as an invited assistant and research scholar. He is co-founder and co-director of Space Transcribers, an architectural non-profit organization in Portugal since 2015 that explores ways to collaboratively investigate, represent and imagine the built environment.

He is currently a Ph.D. candidate at the EAAD, co-supervised by the Vrije Universiteit in Brussels, researching the links between phycological ecosystems and the built environment. His research aims to shift the analysis of the built environment away from solely anthropic and urbanization narratives towards others that place the history of non-human species and marine ecosystems at the center of the discourse.
https://danielduartepereira.com    @danielduartep_

1 These various names were gathered from multiple sources, including https://www.sealifebase.se/comnames/CommonNamesList.php?ID=125251 (last accessed on October 27, 2023).

2 Food & Agriculture Organization of the United Nations (2021). ‘Seaweeds and Microalgae: An Overview for Unlocking Their Potential in Global Aquaculture Development.’ https://doi.org/10.4060/cb5670en.

3 Hwang, Eun Kyoung, Jae Min Baek, and Chan Sun Park (2008). ‘Cultivation of the Green Alga, Codium Fragile (Suringar) Hariot, by Artificial Seed Production in Korea’. Journal of Applied Phycology 20, no. 5 (October): 469–75. https://doi.org/10.1007/s10811-007-9265-5.

4 Carlton, J.T. (1999) ‘The scale and ecological consequences of biological invasions in the World’s oceans’. Invasive species and biodiversity management (ed. by O.T. Sandlund, P.J. Schei and A. Viken), Kluwer Academic Publishers, the Netherlands, pp. 195 –212.

5 Provan, Jim, David Booth, Nicola P. Todd, Gemma E. Beatty, and Christine A. Maggs (2008). ‘Tracking Biological Invasions in Space and Time: Elucidating the Invasive History of the Green Alga Codium Fragile Using Old DNA’. Diversity and Distributions 14, no. 2 (March): 343–54. https://doi.org/10.1111/j.1472-4642.2007.00420.x.

6 Government of Canada, Fisheries and Oceans Canada (2019). ‘Oyster Thief’. Fisheries and Oceans Canada, 9 April. https://www.dfo-mpo.gc.ca/species-especes/profiles-profils/oysterthief-codiumfragile-eng.html.

7 Jue, Melody (2021). ‘The Media of Seaweed: Between Kelp Forest and Archive’. In Saturation: An Elemental Politics, edited by Rafico Ruiz and Melody Jue, 185–204. Elements. Durham London: Duke University Press. https://doi.org/10.1215/9781478013044-011

8 Garascia, Ann (2019). ‘“Impressions of Plants Themselves”: Materializing Eco-Archival Practices with Anna Atkins’s Photographs of British Algae’. Victorian Literature and Culture 47, no. 2: 267–303. https://doi.org/10.1017/S1060150318001511.