Advancing salmon welfare: Mowi’s post-smolt strategy

At Mowi, the health and welfare of our salmon are at the heart of everything we do. We are committed to advancing sustainable practices, ensuring the well-being of our fish, and providing high-quality products for consumers worldwide.

One of the most important advancements in modern aquaculture is post-smolt processing. This innovative approach allows us to rear larger, more resilient salmon before they enter our open sea pens. This strategy has been instrumental in helping Mowi achieve a record-high harvest volume of 502 tonnes of salmon in 2024. 

What is post-smolt processing?

Traditionally, young salmon, known as smolts, are transferred from freshwater hatcheries to sea farms when they are much younger. However, moving smolts at this early stage can increase mortality rates, susceptibility to disease, and stress, undermining the aquaculture industry’s sustainability efforts.

Here at Mowi, we’re rethinking this process. By extending the freshwater phase in our post-smolt facilities, we can significantly enhance fish health and welfare whilst reducing their time in open waters. Our post-smolt strategy allows us to reduce the time Mowi salmon spend in sea by up to six months, substantially improving biological KPIs. 

Why does it matter?

Extending the time our smolts spend in freshwater benefits the fish and the environment. By allowing smolts additional time to grow larger and stronger, they develop into healthier, more resilient salmon. This improves the quality of the final product and helps the fish withstand the harsher conditions of the open seas. Additionally, by shortening the time salmon spend at sea, we can reduce our overall environmental footprint, contributing to the industry’s long-term sustainability.

As well as the fish health and environmental benefits, post smolt production is also a smart business decision for Mowi. It has been the instrumental factor in increasing our harvest volumes in recent years, increases license turnover and reduces costs. 

Turning ideas into action

Mowi continually invests in our post-smolt facilities across our global operations.

Our Nordheim hatchery in Norway is one example of how our commitment to innovation is shaping the future of aquaculture. We use cutting-edge technology to raise smolts on land, which can grow in highly monitored conditions before transitioning to pens in the sea.

This meticulous approach ensures the fish are transferred in optimal conditions, reducing stress and maximising their chances of thriving in the ocean.

In Scotland, when our salmon reach a specific size, they are transported from our indoor freshwater tanks to net pens at our freshwater loch sites to continue their growth before moving out to sea. These freshwater sites are much closer to the shore than our seawater sites, providing more protection to our smaller salmon. 

Although the process varies by region, the benefits of post-smolt remain consistent across our global farming operations, and we are committed to maximising the success of our salmon worldwide. 

A more sustainable future

Post-smolt farming is not just about better fish welfare—it’s about building a more sustainable industry. By reducing the time our salmon spend at sea, we’re reducing our environmental footprint whilst producing high-quality salmon products to feed consumers worldwide. 

At Mowi, we remain committed to continuous improvement, investing in new technologies, and leading the way in responsible aquaculture. Our post-smolt strategy is already delivering success and will remain a key priority for Mowi as we continue to realise its benefits.