Strong Interest in Biodegradable Solutions for Seaweed Cultivation

September 13th, 2026 |

Seaweed farming

Invited participants from Norway, Sweden, Denmark, the United Kingdom, Ireland, and South Africa contributed to the workshop, which was held on 25 June this year. The event builds on a growing interest across the seaweed sector in accelerating the adoption of sustainable substrates, both for commercial cultivation and the restoration of marine ecosystems. The workshop brought together leading industry stakeholders, material developers, and researchers from Europe and South Africa to share practical experiences and discuss common challenges related to the sustainable use of substrates.

Discussions tackled key operational bottlenecks across biodegradable twines, direct seeding substrates, carrier rope reuse, and habitat restoration. While materials such as wool, cotton, cellulose, and bio-based polymers show promising potential, achieving predictable degradation timelines and consistent manufacturing quality, including managing chemical residues like spinning oils, remains essential. Participants highlighted biodegradable twines as perhaps “the lowest hanging fruit” when it comes to cultivation practices, that can provide major operational benefits by simplifying harvest logistics and eliminating the labour-intensive removal of old twine from carrier ropes post harvesting. While restoration initiatives on the other hand, require safe, ephemeral materials that persist just long enough for juvenile kelp to naturally anchor.

The key takeaway was a strong willingness for cross-border collaboration, with widespread interest from farmers and partners to join coordinated field trials for the upcoming deployment season to accelerate learning. By testing the most promising sustainable substrates simultaneously across multiple nursery and farm environments, the industry can build the reliable, standardised dataset needed to scale sustainable practices.

Substrat

In seaweed cultivation, a substrate refers to the material or surface on which the seaweed grows or attaches, particularly during the early stages of cultivation. Examples of substrates include string on which juvenile seaweed grows in the hatchery, and which is later wound around a cultivation line at sea; ropes or lines to which the seaweed attaches directly; and ribbons, textiles, or other fibrous materials used for seeding and deployment.

In kelp forest restoration, substrates may include temporary materials that hold juvenile kelp plants in place until they have naturally attached to rocks or other surfaces.