Scotland’s SAIC funded “Gill Health in Scottish Farmed Salmon” project 2018 – 2023: Highlights.

This unprecedented industry-wide collaboration of all major salmon producers in Scotland and other industry stakeholders ran for 4.5 years. The objective was to identify measures to prevent or reduce gill disease in farmed salmon using a multidisciplinary approach, combining novel methods with well tested techniques.
Eight salmon farms were sampled bi-weekly from stocking until harvesting: monitoring gross fish and gill pathology, biochemistry, haematology and PCR signals from putative pathogens and gill microbiome. In addition, historical data were collected and analysed from all sites in Scotland owned by participating producers (2013–2019).
Highlight project achievements were:
• Standardizing data collection and sharing with multiple partners.
• Literature review of epidemiology of complex gill disease (CGD):
Boerlage et al., 2020: Rev. Aquac. 12, 2140-2159.
• Comparison of CGD histopathology in Norway, Scotland, and Ireland:
Noguera et al., 2019: Bull. Eur. Ass. Fish Pathol. 39(4), 172.
• Data-driven case definitions for CGD and amoebic gill disease (AGD)
• Prevalence estimation of gill disease (2013–2020).
• Surveillance: estimating diagnostic performance of common tests for AGD and CGD:
Boerlage et al., 2022: Prev. Vet. Med. 204, 105654.
• Surveillance: determine appropriate sample sizes for gross gill scoring
(https://epidemiology.sruc.ac.uk/shiny/apps/gillhealth/)
• Estimating risk factors and biomarkers.
• Better understanding of the gill microbiome.