New case study: supporting reliable, sustainable cleaner fish production for Scottish aquaculture
Ballan wrasse are important for sustainable salmon farming, helping to control sea lice naturally by feeding on them. To reduce pressure on wild stocks, the aquaculture sector has been working to produce these cleaner fish reliably in hatcheries. Ballan wrasse have proved challenging to rear, with issues such as skeletal deformities, kidney problems and inconsistent survival limiting production.
The ‘Ballan+ and BallanP’ projects set out to build the scientific foundations needed for successful, ethical hatchery production. Valued at £651k, the project partners were Otter Ferry Seafish, BioMar Ltd, University of Stirling, Mowi Scotland, and Scottish Sea Farms
Ballan+ mapped how and when key developmental issues arise in early life, examining more than 20 batches of hatchery fish. The project also tested how nutrition, minerals and environmental conditions influence bone and kidney health. Alongside this, researchers developed controlled challenge models to study immune responses, creating tools that can be used to test new feeds and robustness‑boosting interventions.
BallanP followed on by exploring the specific phosphorus needs of Ballan wrasse. It compared different phosphorus levels and two common dietary sources. The results showed that one source, monocalcium phosphate (MCP), supports strong growth and balanced mineral health, while the alternative, monosodium phosphate (MSP), can disrupt metabolism and reduce performance.
Together, these projects provide practical guidance for hatcheries, clearer nutritional requirements, and new tools for testing fish health.
The full title of this project is ‘Nutritional, developmental, and immunological advances in farmed cleaner fish’.
Read the case studyShare this