Eelgrass (Zostera sp.), a genus of modest marine plants with a significant ecological impact, possesses layers of importance that encompass both cultural and environmental dimensions. On the Sonoran coast of the Gulf of California, the Comcáac people have cultivated a deep, ancestral relationship with eelgrass; for millennia, this plant has nourished the Comcáac and symbolized their sustainable interaction with the marine ecosystem. Across the globe, on the temperate shores of Denmark, the centuries-old art of eelgrass thatching is steadily being revived, exemplifying another way this plant has shaped daily life. Yet eelgrass’s impact stretches well beyond its roots in these shoreline communities—in recent years, it has drawn global interest for its dual promise as a superfood and a climate ally. While the Comcáac and Danish, among other cultures, have long understood its value, contemporary artisans, chefs, and conservationists alike are now seeking to highlight eelgrass’s potential to transform gastronomy, revolutionize green development, and support ecological restoration. Simultaneously, scientists recognize eelgrass meadows as keystones of biodiversity and critical buffers against environmental degradation, and as eelgrass disappears from oceans worldwide, its preservation becomes an urgent priority. This article delves into the multifaceted role of eelgrass, weaving together the voices of Indigenous stewards, chefs, thatchers, and ecologists to highlight its significance and the collaborative effort to protect it for future generations.
Among the Comcáac people of the Sonoran coast, eelgrass is deeply woven into culinary tradition and cultural celebration. Each year in the village of Punta Chueca, Comcáac women gather to pile sheets of dried eelgrass high and sing the hataam, an ancestral song dedicated to the plant. They beat the eelgrass and rub it between their palms to extract the small, green seeds nestled within. In cmiique iitim, the Comcáac language, these seeds are known as xnois. For millennia, eelgrass seed has been part of Comcáac culture; traditionally, xnois flour has been utilized in tortillas and added to a hot drink that combines xnois with sea turtle oil and honey. The Comcáac are the only Indigenous group that consumes the xnois seed, but now, this ancestral food is reaching international audiences—today, non-Comcáac chefs are attempting to bring eelgrass onto their menus. Biologist and chef Greg Martinez at Michelin-starred chef Angel Leon’s restaurant Aponiente in Cádiz, Spain, has been interested in pursuing the gastronomic potential of this superfood since 2018 after reading about its documented use as a grain by the Comcáac. Juan Martin, another biologist with Aponiente, says they conducted studies on the seeds, realizing their nutritional value: they are gluten-free and full of protein, fiber, and healthy fats. It’s no wonder the Comcáac have long relied on xnois to sustain them during long sea voyages (KJZZ, 2022).
At Aponiente, staff are also pursuing seagrass cultivation. They began by transplanting eelgrass from northern Spain to abandoned salt marshes in the coastal Cádiz region. Now, the transplanted eelgrass beds support regional biodiversity by providing habitat for seahorses, scallops, and other marine species, as well as sequestering blue carbon below the water’s surface and buffering shorelines from coastal storms. Though the project is in its early stages, with much more eelgrass growth needed before it will be ready for harvest and use in cooking, Martin is optimistic about the future of eelgrass as a climate-friendly, sustainable food source and credits the Comcáac for inspiring this project (KJZZ, 2022).
In the Comcáac territory, there are also ongoing efforts to protect eelgrass so that it may continue to provide sustenance for humans and wildlife in the region. About a third of the Canal del Infiernillo, a 116 square-mile channel between the coast and Tiburón Island, is covered in eelgrass meadows. Given the volume of eelgrass in this region, researchers are accordingly motivated to study this carbon capture and the potential to transplant or seed eelgrass to other areas (KJZZ, 2022).
Protected under the RAMSAR wetlands convention and designated as a UNESCO World Heritage Site and Biosphere Reserve, the Canal del Infiernillo is one of the only areas in the Gulf of California where eelgrass is still found (Ramsar Sites Information Service [RSIS], n.d.). At this site, scientists have documented 81 endemic invertebrate species of the Gulf of California and several threatened species, such as totoaba (Totoaba macdonaldi), marine turtles (Eretmochelys imbricata, Caretta caretta, Dermochelys coriaceai, Lepidochelys olivacea, and Chelonia mydas agassizi) mangroves (Avicennia germinans, Laguncularia racemosa, and Rhizophora mangle), and Brant Goose (Branta bernicla) (Ramsar Sites Information Service [RSIS], n.d.).
Additionally, these wetlands provide substrate, refuge, and food to several species that are the foundations of commercial and artisanal fisheries. For the 2,000+ years they have inhabited this region, the Comcáac have demonstrated extensive traditional ecological knowledge that informs their fisheries management practice. While these eelgrass beds have not been disturbed by the nets of commercial shrimp fishing vessels, a concern for other regions of the Gulf, they are still under the threat of overfishing and tourist development (KJZZ, 2022). Because eelgrass beds are currently disappearing from the world’s oceans, it is especially crucial to protect the population in the Canal del Infiernillo and the ecosystem services it offers.
In the much cooler climate of Denmark, eelgrass has not traditionally been used as a food source but rather as a construction material. When it washes up along Denmark’s shorelines, eelgrass naturally hardens and forms paper-mâché-like layers with air pockets, allowing it to repel rain, resist rot due to its salt content, and even withstand fire. On the island of Læsø, Henning Johansen has been reviving the ancestral craft of eelgrass thatching since 2010—a practice for which he received an award from the European Commission (D’Onfro, 2023). Using centuries-old techniques, Johansen restores and protects the island’s historic homes with harvested eelgrass (D’Onfro, 2023). These methods were pioneered by Danish women as early as the 1600s, who worked in groups of forty to fifty to craft roofs that can last for over three hundred years (UNESCO, n.d.). A single thatched roof can take months to complete, requiring up to 90 tonnes of eelgrass, which is spun into rope, wrapped around timber frames, and piled layer upon layer. In 2023, this unique building tradition helped secure Læsø’s designation as a UNESCO World Heritage site (D’Onfro, 2023). Notably, UNESCO recognizes eelgrass as a sustainable building material that continues to sequester carbon even after drying. With the buildings and construction sector responsible for 37% of global greenhouse gas emissions (United Nations Environment Programme [UNEP], 2022), it is vital to reduce reliance on high-carbon materials like cement, aluminum, and steel and instead invest in regenerative, low-impact, and natural alternatives like eelgrass.
However, we must be careful not to overexploit eelgrass in the pursuit of bio-based construction materials or gastronomic innovation. Dr. Dorte Krause-Jensen, a marine ecologist at Denmark’s Aarhus University, supports the moderate use of eelgrass as a building material but stresses that we must also recognize its vital ecological functions—protecting shorelines, supporting biodiversity, and sustaining salt meadow and beach communities (D’Onfro, 2023). Balancing conservation goals with eelgrass’s emerging uses requires thoughtful, sustainable management. This includes harvesting wrack only from non-sensitive areas, promoting eelgrass cultivation in degraded or abandoned habitats, and integrating traditional ecological knowledge into modern practices. Global frameworks like RAMSAR and UNESCO must advocate for protective measures while encouraging innovative, low-impact applications that respect eelgrass’s role in the marine ecosystem. Engaging local communities and fostering international collaboration will be key to ensuring that eelgrass meadows remain resilient, even as their potential is responsibly explored.
Eelgrass represents a unique nexus where tradition, innovation, and ecological stewardship intersect. From its ancestral use by the Comcáac people and Danish thatchers to its emerging applications in gastronomy and green construction, this unassuming marine plant continues to demonstrate its value across disciplines and cultures. However, its ecological significance as a keystone species and climate ally must remain central to all efforts to responsibly harness its potential. These stories of eelgrass remind us that sustainable progress depends on respecting natural systems and learning from those who have long lived in harmony with them. By fostering collaboration between scientists, local communities, policymakers, and industries, we can ensure that eelgrass meadows thrive for generations to come, embodying a model for how humanity can innovate while preserving the integrity of the ecosystems on which we depend.
