AquaGill project delivers breakthrough in predicting gill health in farmed salmon

The AquaGill project set out to develop a faster, more scalable way to assess gill health using molecular biomarkers

 

 

Gill health is one of the most important factors affecting the wellbeing and performance of farmed Atlantic salmon. Conditions such as complex gill disease, amoebic gill disease, and irritation from environmental stressors like micro‑jellyfish can lead to significant stock losses.

Traditional diagnostic methods rely on microscopic tissue examination, which is accurate but slow, labour‑intensive, and impractical for routine monitoring at commercial scale.

To address this challenge, the AquaGill project set out to develop a faster, more scalable way to assess gill health using molecular biomarkers. These biomarkers act as early warning signals, indicating how gill tissue responds to stress or disease before major damage becomes visible.

Valued at over £480k, the project partners were the Scottish Fish Immunology Research Centre, Scottish Sea Farms, and the University of Aberdeen.

Building on an extensive gill biobank from Scotland and Tasmania, the team analysed hundreds of samples to identify a focused set of genes strongly linked with gill damage. Using machine learning, they developed a predictive panel capable of distinguishing healthy from affected fish with high accuracy. Importantly, this molecular signature held up not only in controlled studies but also in real‑world conditions, including during natural micro‑jellyfish exposures.

The project also explored whether non‑destructive sampling, e.g., simple gill swabs, could replace traditional tissue collection. Early results are promising, showing that swabs can capture enough genetic material to detect key biomarkers, opening the door to welfare‑friendly, repeatable monitoring.

The AquaGill represents a major step towards rapid, data‑driven gill health assessment. With further development, this approach could support earlier interventions, reduce mortality, and strengthen the resilience of salmon farming as environmental pressures continue to grow. Commercial opportunities are now being explored to bring this innovation into industry practice.

The full title of this project is ‘A biomarker-based approach to predicting gill health in Atlantic salmon’.

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