Luxury fashion is turning to seaweed leather as the next big sustainable innovation, offering a regenerative, biodegradable alternative to traditional leather.
For centuries, leather has been a symbol of luxury, craftsmanship, and durability. But as fashion reckons with its environmental footprint, the quest for alternatives has intensified. Enter seaweed, an unassuming marine force that’s quietly making its way into the sustainable materials conversation. While mushroom-based and plant-derived leathers have grabbed headlines, seaweed leather is emerging as an unexpected contender, offering an eco-friendly alternative that is both regenerative and versatile.
Seaweed is already a staple in industries ranging from food to pharmaceuticals, but its potential in fashion may come to rival its other uses. Unlike traditional leather production, which contributes significantly to deforestation, water pollution, and carbon emissions, seaweed requires no fresh water, no fertilizers, and no land-based resources. It grows at an astonishing rate — some species can expand up to two feet per day — making it one of the most renewable biomaterials on the planet. More importantly, it absorbs carbon dioxide as it grows, acting as a natural carbon sink, which aligns with the fashion industry’s growing focus on carbon-negative materials.
Early pioneers in seaweed-based leather are beginning to surface. LanzaTech, known for its carbon recycling technology, is investing in algae- and seaweed-based solutions that could soon rival more widely recognized alternatives like mushroom leather. Meanwhile, biomaterial startups such as TômTex are experimenting with chitosan, a biopolymer derived from shellfish, to create textile innovations that mimic the feel and durability of animal leather.
Off the coast of Namibia, a startup called Kelp Blue is pushing seaweed’s potential even further. In the waters near a former diamond mining town, the company has established a sprawling underwater kelp forest designed to restore marine biodiversity, absorb carbon, and create sustainable raw materials. Every morning, a team of workers ventures offshore to trim the giant kelp, which can grow up to 164 feet long. The harvested seaweed is then processed into an agricultural biostimulant that helps improve soil health, but Kelp Blue is also looking toward high-value industries — fashion being one of them. The company plans to use the leftover seaweed from its farming operations to develop a leather alternative, a move that could help scale the material beyond the boutique, experimental phase.
As more companies explore seaweed’s potential, researchers are uncovering its ability to sequester carbon at unprecedented levels. Some of the harvested kelp breaks off and sinks deep into the ocean, locking away carbon for centuries in a process similar to how oil fields were originally formed. The startup has been recognized as a finalist in the prestigious X Prize for carbon removal, which challenges businesses to create large-scale solutions capable of removing a gigaton of CO2 per year. Though that scale is still far off, Kelp Blue’s growing offshore operations are proving that regenerative ocean farming could play a vital role in both fashion and climate solutions.
North Carolina-based Keel Labs’ flagship product, Kelsun fiber is derived from seaweed biopolymers. While not leather, the material serves as an indicator of the potential; it’s a “plug-and-play” replacement for conventional fibers, seamlessly integrating into existing textile production processes while offering a significantly lower environmental footprint. This seaweed-based fiber is 100 percent biodegradable, aligning with the fashion industry’s shift toward circularity and reduced waste. Last year, Keel Labs collaborated with pro surfer Kelly Slater’s sustainable fashion brand Outerknown to launch the first commercial product featuring Kelsun fiber, the label’s popular Blanket Shirt.
“It’s been 10 years since we made the first one, and we are proud to be partnering with Keel Labs on the next generation of this shirt with a version made from Kelsun,” Slater said in a statement. “Working with suppliers that share our love for the ocean is a great fit for Outerknown. I’m excited to see this grow.”
One of the most promising aspects of seaweed leather is its potential for circularity. Traditional leather production often relies on toxic chemicals such as chromium, which poses environmental and health risks. In contrast, seaweed-based materials are biodegradable, meaning they won’t linger in landfills for centuries like synthetic alternatives. Additionally, some formulations of seaweed leather incorporate waste streams from the food industry, giving new life to what would otherwise be discarded biomass. This means that not only is seaweed leather a solution to fashion’s over-reliance on resource-intensive animal hides, but it also offers a blueprint for zero-waste material development.
While seaweed leather is still in its infancy, brands are already beginning to experiment with it. Scandinavian fashion house Ganni has signaled interest in next-generation biomaterials, and seaweed-derived fabrics have appeared in concept collections from forward-thinking designers. A recent report from the Material Innovation Initiative revealed that the global market for bio-based alternatives to leather is projected to grow at an annual rate of 9.3 percent, signaling strong investor and consumer interest in these materials. Fashion industry insiders predict that within the next decade, innovations in biofabrication will make seaweed leather a mainstream textile choice, particularly as luxury houses seek to burnish their sustainability credentials.
Yet, challenges remain. Like all new materials, seaweed leather must prove its scalability and durability before it can compete with traditional leather on a commercial level. The processing techniques required to transform seaweed into a leather-like material are still being refined, and cost remains a barrier for mass adoption. Industry insiders suggest that within the next five to ten years, technological advancements will drive costs down and improve the material’s performance, making it a viable competitor in luxury fashion. Some brands have expressed skepticism about its durability compared to more established bio-based materials like mycelium leather, but continued research and development could close that gap.
Still, the momentum behind seaweed leather is growing. With luxury brands under increasing pressure to reduce their reliance on animal products and synthetic alternatives, biofabricated materials are no longer a fringe experiment but a necessary evolution. European luxury conglomerates such as LVMH and Kering have both invested in next-generation material startups, signaling that alternatives to traditional leather are not just a passing trend but an essential pivot for the future of fashion. And if history has proven anything, it’s that the industry has a knack for turning the unconventional into the covetable.
Related on Ethos:
