The KelpRing project, led by Sgurr Services Ltd., tested an innovative design to create a natural habitat for cleaner fish (wrasse) within a salmon farm. The wrasse play an essential role in fish farms by eliminating lice, but also have a high mortality rate. The KelpRing was designed to provide the wrasse with their own natural kelp forest habitat, helping to improve the health and welfare of the cleaner fish
The KelpRings were deployed in salmon sea pens in an industrial scale trial at Loch Duart, in the North Atlantic waters of northwest Scotland. During the feasibility study, the cleaner fish were seen swimming, resting and hiding in the KelpRing. Researchers believe the wrasse were able to interact with the salmon in a more natural environment similar to what the fish experience in the wild. Additionally, the cleaner fish seemed to prefer the KelpRing as compared to the fake, plastic hides currently used in the industry.
Benefits to aquaculture farms
The kelp had the additional benefit of helping to re-oxygenate the water and absorb some of the polluting phosphates or nitrates which are produced in salmon faeces, therefore reducing the environmental impacts of the fish farm.
The project also received positive feedback from the salmon company staff, showing that the KelpRing can be integrated easily into current fish farming practices. In particular, staff welcomed the reduction of their workload, as the KelpRing does not require the same level of maintenance as the plastic, fake hides.
Aquaculture plays a vital role in our economy, supporting jobs – often in rural areas – around the UK, and providing seafood and nutritional security. The results of the Kelpring project come as the government has announced new regulations for harvesting wild wrasse to use as cleaner fish in salmon farms, reflecting the growing awareness and importance of fish welfare in farms. These new rules will be effective from May 2021, aiming to sustainably grow the industry whilst balancing economic, environment and social responsibilities.
The KelpRing is one innovative way that has been shown to improve fish welfare and reduce some of the environmental impacts involved in fish farming.