Oceans are critical ecosystems for planetary health—they regulate the climate, support immense biodiversity, and provide valuable resources for food and shelter. Today, the aquatic environment is gravely threatened by global industrial systems dependent on fossil fuels—from rising temperatures that transform ocean chemistry, raise sea levels, and fuel extreme weather, to pollutants such as microplastics and trash that leak into water from the land. 

Yet the ocean is also a source of possibility for the built environment, offering innovative materials for healthy buildings and the potential to remediate marine landscapes through new cultivation, harvesting and manufacturing. Sargassum, a genus of brown macroalgae now inundating shorelines, can be compressed into masonry blocks and cement composites for construction, turning an ecological nuisance into a low-carbon building material. Seagrass has been used as roof thatch for generations in many regions, and recent studies show pressed eelgrass (Zostera marina) mats can match the thermal performance of conventional wood-fiber insulation. And as seaweed farming expands globally, kelp and other macroalgae are being studied as feedstock for bioplastics and biocomposites, and for their carbon sequestration potential. From naturally occurring materials to cultivated aquatic crops, the ocean offers material pathways toward a resilient, healthy, carbon-free future on land and at sea. 

This event is part of an ongoing series co-hosted by Healthy Materials Lab and The Architectural League of New York that investigates the architectural possibilities of plant- and earth-based materials.

^Sources:

^{Kuqo, A., & Mai, C. (2023). Flexible Insulation Mats from Zostera marina Seagrass. Journal of Natural Fibers, 20(1). https://doi.org/10.1080/15440478.2022.2154303}

^{Pessarrodona, A., Howard, J., Pidgeon, E., Wernberg, T., & Filbee-Dexter, K. (2024). Carbon removal and climate change mitigation by seaweed farming: A state of knowledge review. The Science of the total environment, 918, 170525. https://doi.org/10.1016/j.scitotenv.2024.170525}

^{López-Sosa LB, Rodríguez-Torres GM, Rodríguez-Martínez RE, et al. Multifunctional characterization of cement-Sargassum composites for application as bioconstruction materials. Journal of Building Physics. 2025;48(5):794-820. doi:10.1177/17442591241276396}

^{Mattio, L., Payri, C.E. 190 Years of Sargassum Taxonomy, Facing the Advent of DNA Phylogenies. Bot. Rev. 77, 31–70 (2011). https://doi.org/10.1007/s12229-010-9060-x}

SHANJANA MAHMUD and LUKE EDDINS are Founders and Co-Executive Directors of Seaweed City, an environmental organization that grows seaweed along New York City’s coastline to clean the water, rebuild marine ecosystems, and support coastal resilience. Shanjana is an artist, activist, and sea farmer. She studied biology and painting at Southern Methodist University and received her MFA from the University of Pennsylvania. Her work centers the water. Luke is a designer, fabricator and aquaculturist. He studied art at Oberlin College and architecture at Parsons School of Design. His current work is focused on zero-waste and urban aquaculture.  

TOBIAS ØHRSTRØM is Co-founder and Head of R&D, Design & Creative Direction of Søuld, a Danish company pioneering the use of eelgrass as a building material. Originally trained as an engineer and architect, Tobias has a decade of experience as a project architect at high-end Danish design studios where he gained broad technical knowledge and an understanding of designers’ priorities. He ensures Søuld’s eelgrass products are buildable with high design and materiality standards and has driven the company’s material development since its founding. With his strong sense of design and materiality, Tobias controls the creative direction of Søuld and oversees the strategic collaborations that Søuld enters into. Most recently, Søuld has embarked on an international collaboration with Spinneybeck/MillerKnoll.

Join us for an in-depth conversation with experts in ocean farming and sourcing alongside manufacturers of biobased marine products and designers to discuss how we can learn from, repair, and build with the world’s oceans. 

This event is part of an ongoing series co-hosted by Healthy Materials Lab and The Architectural League of New York that investigates the architectural possibilities of plant- and earth-based materials.

Registration opens soon.  

Recordings from past events in this series are available here: Events on Demand. 

Special thanks to UNFOLD PROJECTS for their support of this program.