AquaGen: Breeding for robustness

A broad breeding goal

AquaGen’s breeding programmes, refined for Scottish conditions since 2018, draw on more than fifty years of selective breeding and a broad genetic base spanning 41 Norwegian rivers. Since then, family-based selection and carefully controlled pairings allow quality, disease resistance and growth to be selected for together, and not traded off against one another. Today, genomic selection uses DNA- level information to do this more accurately and efficiently. For each generation, physical and genomic data from Scottish production sites is weighed against the genetic profile of individual fish, ensuring broodstock are chosen not only for how they perform, but for the genetic raw material they pass on — a broad breeding goal designed not just to reduce time at sea, but increase robustness and performance at the same time.

Tackling disease, one trait at a time

Disease resistance is often heritable, but the underlying genetic architecture that enables resistance differs from one disease to the next. AquaGen’s genetic experts tackle each challenge individually and on its own terms. Genomic selection, introduced in 2013, reads tens of thousands of DNA markers to identify broodstock with the strongest natural resistance. For Cardiomyopathy Syndrome (CMS), caused by the piscine myocarditis virus, selection for CMS resistance reduces viral load, leading to less heart damage. This approach has driven major gains and in Norway the proportion of offspring testing virus- free after controlled challenge testing has climbed from around 2% in 2018 to 25% in 2025. A comparable programme targeting infectious pancreatic necrosis (IPN) cut yearly outbreaks in Norway by 75% within five years of introducing resistant eggs. AquaGen Scotland is now working to bring CMS resistance into its own Elite breeding population, alongside its established GAIN (growth) and SHIELD (disease resistance) product lines.

Robust genetics

75% fewer IPN outbreaks in Norway within five years of introducing resistant eggs

2% → 25% rise in CMS-virus-free offspring after challenge testing 2018 – 2025

— Half the time at sea to reach harvest size from generation 7 to 13

— 80%+ ova survival from fertilisation to packing (source AquaGen Scotland)

“Robustness isn’t one single trait — it’s many. Our job is to keep improving each one, generation after generation, so the fish themselves are better equipped for life at sea.”

Thomas Moen, Global R&D Manager, AquaGen.

Gill health: genetics meets a changing climate

Application of AquaGen’s genomic prediction model in two independent validation datasets (ASNO2024 and ASSC2023). Lower gill scores indicate better gill condition. Selection based on genomic predictions produced a clear separation between the best-performing and worst-performing 5% of fish for gill health.

Faster growth, reduced time at sea

Every extra week that a salmon spends at sea is another week of exposure to disease, parasites and environmental stress. Genetic gain in growth rate has been dramatic: AquaGen’s 13th breeding generation reaches harvest size in approximately half the time compared to the 7th generation. This reduced time in the marine phrase leads to improved survival rates, better site optimisation and dramatic reductions in cost, carbon footprint and environmental impact.

Of particular interest to the audience listening to AquaGen’s Global R&D Manager Thomas Moen at the Biomar Pharmaq Knowledge Exchange in Glasgow last month is the emerging research around heart shape associated with rapid growth. Within the AquaGen population, faster-growing salmon have heart shapes that more closely resemble those of wild salmon, suggesting that breeding for performance and breeding for robustness can be complementary goals. The wide-ranging benefits of reduced time at sea are now being complimented with enhanced robustness, bringing multiple benefits for the fish, the farmer and the environment.

“Genetic improvement is a long-term commitment. Every generation builds on the last, delivering salmon that are better equipped to thrive in today’s farming conditions while supporting a more resilient and sustainable future for the Scottish salmon industry."

Keith Drynan, Managing Director, AquaGen Scotland

Investing in Scotland’s genetic future

This genetic progress is backed by sustained investment in Scotland where AquaGen Scotland has recently commissioned a new freshwater Recirculating Aquaculture System (RAS) for ova incubation at Holywood Breeding Centre. This gives precise control over water quality and significantly enhances biosecurity through UV filtration, while reducing energy and water use. In February 2026, the reopening of the export route from AquaGen Norway’s newly certified Profunda facility brought fresh genetic material into the Scottish breeding population, including stronger representation of CMS-resistance markers, alongside valuable backup supply and access to out-of-season eggs. Together, these developments leave AquaGen Scotland well placed to deliver robust genetics for the future of Scottish Salmon.

Generation by generation, the goal remains the same: helping farmed Scottish salmon adapt to — and thrive in — an increasingly challenging marine environment.