New case study: rapid fish health diagnostics - understanding sea lice treatment impacts

Repurposing diagnostic technologies from human and veterinary medicine for assessing the health and impact of sea lice treatments

Sea lice pose a challenge in salmon and trout aquaculture. Current health assessments rely on histology, which can be costly and time-consuming. This project aimed to develop a rapid, non-lethal, and cost-effective diagnostic method to improve fish welfare and farm productivity.

Valued at over £420k, the partners were the University of the West of Scotland, Kames Fish Farm Ltd, Mowi, Randox Diagnostics, and Europharma.

The approach repurposed automated medical diagnostic technologies to measure clinical chemistry biomarkers in fish blood, enabling large-scale, high-throughput health assessments. Objectives included establishing baseline biomarker levels in Atlantic salmon and Rainbow trout, evaluating chronic impacts of sea lice treatments, and optimising husbandry practices.

Key achievements:

• Biomarker database: 22 clinical chemistry endpoints were validated and measured over almost a year, creating reference ranges for salmon and trout.
• Technical innovations: protocols for blood collection, serum processing, and storage were standardised to minimise variability.
• Treatment impact analysis: sampling before and after various treatments assessed stress effects.

Commercially, this method offers faster, on-site diagnostics compared to traditional histology, reducing costs and enabling timely interventions. By correlating biomarkers with treatment impacts, farms can tailor strategies to minimise stress, reduce mortality, and improve feeding efficiency.

This project exceeded its original scope thanks to strong industry collaboration, delivering a validated diagnostic platform and actionable insights that are already influencing husbandry practices. Future work will focus on integrating these techniques into routine health monitoring, supporting sustainable aquaculture growth.

The full title of this project is ‘Development of diagnostic techniques to assess fish health and impact of sea lice treatment’.

Read the case study