From Sea to Seam: Can the Ocean Reshape What Our Clothes Are Made Of? – Seen Blue Conservation

Beyond Plastic: The Rise of Marine Biomaterials Katharina Nøkling-Eide is a research scientist trying to build on Europe’s long tradition of utilizing seaweed. As part of the SeaWeave project, she investigates how red and brown seaweed can be turned into innovative and sustainable fibers and dyes. The main advantage of using seaweed as a textile feedstock lies in the minimal input factors required to grow it – just nutrients naturally occurring in seawater, CO₂, and light – compared to the freshwater and fertilizer-intensive cultivation of terrestrial crops such as cotton. Seaweeds contain unique compounds such as alginates, carrageenan, and agar, so-called hydrocolloids. These naturally occurring polymers, already widely used as gelling agents, are now being explored as the basis for textile fibers. At the same time, pigments like fucoxanthin (brown) and phycobiliproteins (red, blue, or turquoise) could enable integrated biorefinery processes where both fibers and natural dyes are extracted from the same biomass. The goal is ambitious: clothes made entirely from seaweed, making them fully biodegradable. Yet translating seaweed into textiles is far from straightforward. “One of the main challenges is the high ash content in seaweed, which can create difficulties during fiber processing, particularly in spinning,” Katharina explains. At the same time, the material’s high water content of up to 90 percent makes cheap and energy-efficient drying a critical bottleneck. Scaling will be fundamental: “To make a meaningful impact in the textile industry, production would need to reach several thousand tons of biomass.”, she emphasizes, noting that large-scale cultivation must be carefully managed to avoid environmental impacts such as nutrient depletion in the water column. One way to reduce this pressure is to make better use of existing resources, for example, by using by-products of kelp, that are discarded by the food industry. Done right, this expansion could not only limit environmental impact of textiles but also create new economic opportunities in coastal communities.