Traditionally, salmon eggs are imported to Scotland then reared in freshwater hatcheries before being transferred to marine farms for on growing. However, since 2020, Scottish Sea Farms has been working with AquaGen to select the best performing fish from its own marine farms and produce offspring from those.

Scottish Sea Farms Head of Fish Welfare Dr Ralph Bickerdike said: ‘Ultimately, we’re seeking to match the right stock to the right conditions in order to maximise fish welfare. As climate conditions continue to change – and with it, the marine environment – we’re acting now to help ensure future stocks can withstand those changes.’

Already, Scottish Sea Farms has reduced the time its fish require at sea by two months, thanks to its new £58M state-of-the-art hatchery at Barcaldine near Oban.

This latest initiative aims to maximise fish welfare once at sea, by improving overall robustness to Scottish marine conditions and increasing resistance to the health challenges that the changing environment can give rise to – in particular, gill health which is now thought to be one of the biggest challenges facing farmed salmon globally.

Said Bickerdike: ‘Climate change presents challenges to livestock farmers of all kinds. For salmon farmers, this summer’s record high temperatures and lower than average rainfall have given rise to increased incidence of gill health issues.

At some farms, fish stocks have been able to overcome such challenges and bounce back to full health. At other individual farms, we’ve seen significant losses, indicating that some salmon are naturally more resistant than others.

Helping determine which genetic selection might offer the greatest resistance is an integral element of the breeding programme.

AquaGen Scotland Managing Director Andrew Reeve said: ‘Stock selection is an ongoing process. Just as the climate continues to change, so too does the best breeding to withstand those changes.

‘Having selected the best performing fish from Scottish Sea Farms marine farms, we’re now able to apply the latest technologies and approaches to identify the key traits that have helped these superior grade fish continue to thrive in the Scottish marine environment.’

Whilst this work is at an early stage, the partners hope to have robust genomic data as soon as three years from now – a timescale that could be shortened further with knowledge exchange from Scottish Sea Farms’ other research projects in this area.

These include a collaboration with the University of Aberdeen, feed specialists BioMar, Marine Scotland Science and the Sustainable Aquaculture Innovation Centre to increase understanding of how seasonality and location influence gill health and how farmed salmon respond to these challenges.

Similarly, it is intended that the insights into breeding for improved resistance to gill health challenges, gleaned through Scottish Sea Farms’ collaboration with AquaGen, will be shared with other producers of farmed salmon, both here in Scotland and further afield.

Before then, the first eggs bred from Scottish Sea Farms grown salmon will be delivered into Barcaldine Hatchery early 2022 and are scheduled to be transferred to the company’s marine farms around Scotland’s west coast and Northern Isles from Q1 2023.