Sheep wool is emerging as a viable, plastic-free alternative for commercial seaweed farming, according to engineers from Queen’s University Belfast. The team has spent two years growing kelp on ropes manufactured from the wool of Whiteface sheep bred on Dartmoor, creating a fully circular cultivation system that avoids synthetic marine pollution.
Replacing Plastic Ropes in Commercial Kelp Farming
Traditionally, commercial seaweed aquaculture relies heavily on synthetic polyester fiber ropes to anchor and cultivate crops. According to Kim Kristensen, chief executive and founder of Arctic Seaweed, operators have searched for alternative materials since the very first deployment of seeded lines a decade ago. Standard plastic longlines suffer from mechanical wear and tear, leading to persistent environmental hazards. When these synthetic lines degrade or snap, they release microplastics directly into marine ecosystems. Furthermore, industry data shows that approximately 383 tonnes of these plastic ropes are lost annually at sea in Norway alone. At the end of their operational lifecycle, conventional lines are frequently incinerated or sent to landfill rather than recycled.
Scaling Up Trials in Norway and Iceland
The Queen’s University Belfast project began as a small proof-of-concept on an experimental seaweed farm at Strangford Lough, backed by funding from the EPSRC Impact Acceleration Account (EPSRC IAA). Dr Pamela Walsh, who led the project within the University’s School of Mechanical and Aerospace Engineering, noted that the initial funding acted as a critical catalyst. The research has since expanded internationally through collaborations with industrial partners including The Provenance Company (UK) Ltd and Arctic Seaweed in Norway, progressing to industrial-scale trials in Norway and Iceland.
Additional support from Innovate UK enabled the research team to develop advanced marine ropes and test them at the Trettosen Seaweed Farm in Bergen, Norway. These commercial trials successfully cultivated three distinct seaweed species—Ulva, Saccharina latissimi, and Alaria esculenta—on 100% pure wool longlines. Industry representatives describe this large-scale deployment on pure wool as a first for the sector.
Pro Tip: The Circular Advantage
Unlike synthetic lines that require harsh chemical detergents to strip away residual biomass before reuse, wool ropes and any remaining seaweed biomass can be directly processed into agricultural fertilizers at the end of the growing cycle.
Creating a Circular Bio-Economy for British Wool
The integration of agricultural textiles into aquaculture bridges two distinct industries. Kim Stead, founder of The Provenance Company (UK) Ltd, stated that collaborating with Queen’s University Belfast highlights the capacity of natural materials to tackle major environmental problems. Testing these products in live commercial environments confirms their viability at scale, opening new economic pathways for farmers, British wool producers, and domestic manufacturing.
Frequently Asked Questions
What types of seaweed can be grown on wool ropes?
Industrial trials in Norway successfully cultivated Ulva, Saccharina latissimi, and Alaria esculenta on 100% pure wool longlines.
Why are plastic ropes a problem in aquaculture?
Plastic ropes degrade through wear and tear, shedding microplastics into the ocean, and hundreds of tonnes are lost at sea annually in Norway alone.
What happens to the wool ropes after harvest?
At the end of the growing period, the wool ropes and any residual seaweed biomass can be processed directly into fertilizers.
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