Sheep wool is key to making seaweed farming plastic-free, according to engineers from Queen’s University Belfast.
The experts have been working on an innovative project for the last two years in a bid to drive forward sustainability in the industry.
They have been growing kelp - a large and fast-growing brown seaweed - on the wool of Whiteface sheep breed on Dartmoor, England.
This is then used to create degradable ropes, which the kelp is cultured on.
At the end of the growing period, the wool ropes, along with any residual seaweed biomass, can be processed into fertilisers, creating a fully circular solution, the engineers say.
At present, traditional plastic ropes with residual seaweed are typically treated with detergents to remove biomass and are then reused, contributing to ongoing environmental issues, they explain.
The repeated use of the plastic ropes also increases wear and can lead to the release of microplastics, as well as mechanical failures, causing ropes to be lost at sea.
In Norway, which is a key focus area for the researchers - an estimated 383 tonnes of these plastic ropes are lost annually at sea. This is the same weight as 54 adult African elephants.
At the end of their life, the ropes are often incinerated or sent to landfill, further contributing to environmental harm.
The team of Queen’s engineers, who were funded by the EPSRC Impact Acceleration Account (EPSRC IAA), started the research on Queen’s experimental seaweed farm on Strangford Lough and have since been collaborating with industry partners.
These include the Provenance Company (UK) Ltd and Arctic Seaweeds in Norway.
This has now evolved into industrial-scale trials in Norway and Iceland.
Dr Pamela Walsh from QUB ’s School of Mechanical and Aerospace Engineering said it has “been fantastic to watch this project grow from a small proof-of-concept at Queen’s University’s experimental farm on Strangford Lough to industrial-scale trials in Norway”.
“The EPSRC IAA funding was the catalyst that enabled us to test the concept and we are now confident that plastic-free solutions for seaweed farming can work at scale, in collaboration with our industrial partners.”
Further funding from Innovate UK has allowed the team to develop advanced marine ropes and complete industrial-scale trials, funded by Arctic Seaweeds at the Trettosen Seaweed Farm in Bergen, Norway.
The trials have been successful at cultivating three different types of seaweed species – Ulva, Saccharina latissimi and Alaria esculenta – on 100 per cent pure wool longlines at industrial scale, which is a first for the industry.
Kim Kristensen, CEO and Founder of Arctic Seaweed, comments: “From the very first deployment of seeded lines ten years ago, we have been looking for alternative solutions to the polyester fibre rope most commonly used to cultivate seaweed. We are thrilled to be part of this project, which is helping solve a key challenge in making seaweed farming more sustainable and circular.”
Founder of The Provenance Company (UK) Ltd, Kim Stead, says: “Working with Queen’s University Belfast reflects years of collaboration, innovation, and belief that natural materials can play a vital role in solving some of the world’s most pressing environmental challenges.
“Having the opportunity to test our products in a live commercial environment with Arctic Seaweed has allowed us to prove this concept at scale. This opens an exciting new chapter for our farmers, British wool and British manufacturing, while contributing to a circular economy.”
