Aquaculture Magazine reports:
The world’s largest salmon supplier provides a 40% of the UK’s fresh salmon
Building on the success of previous collaborations between Ridgeway Biologicals and Mowi Scotland that have delivered effective vaccinations to protect fish health, the partnership has now developed a new vaccine strategy to safeguard salmon against the bacteria Yersinia ruckeri.
Bacterial infection by the pathogen can lead to a disease known as enteric red mouth disease (ERM), mainly found in salmonid species. The disease has caused clinical outbreaks and mortalities in salmon populations farmed on the west coast of Scotland.
The work to develop an effective vaccine against Y. ruckeri was initiated in 2022, with the collection and characterization of many isolates across Mowi Scotland farms. The vaccine was then tested in controlled conditions in 2023 and will now be implemented fully within Mowi in 2024, with the first commercial batches to be vaccinated in spring 2024 and results expected in 2025.
The vaccine strategy includes both a dip vaccination early during fish development in freshwater followed by an intraperitoneal injection prior to transfer to sea.
The benefits of this collaboration
Past collaborations between the two companies have included a vaccine to protect against Pasteurella skyensis – first tested in 2021 before fully implementing across all Mowi stock in late 2022. No clinical outbreaks of the bacteria have been reported at any Mowi farms since, even though the bacteria has been detected.
Commenting on the benefits of this collaboration, Herve Migaud, Mowi’s Director of Fish Health, Welfare and Biology, said: “The collaboration has generated a lot of knowledge on the evolution of bacterial communities in farm-raised salmon through the use of biotyping and serotyping technologies at a time when sea waters have reached the highest recorded temperatures on the west coast of Scotland.”
“Monitoring and understanding what the threats are is the first line of defense against clinical outbreaks and the collaboration contributed very significantly to improve the health and welfare of Mowi Scotland stocks and reduce the use of antibiotics.”
Use of antibiotics reduced by 79%
Over the last three years (2021-2023) the use of antibiotics (active ingredient) by Mowi Scotland has been reduced by 79% which shows how successful prevention through vaccine and biosecurity can be.
This collaboration has also showcased how science can be translated into practical solutions for the salmon farming sector.
The Ridgeway-Mowi success is being recognized at the 2024 Aquaculture Awards, with the pair named as finalists in the “Collaboration” category. Awards winners will be announced on Wednesday May 15th in Aviemore.
Mowi provides a 40% of the UK’s fresh salmon
Some weeks before in the United Kingdom (UK), his Majesty’s Revenue and Customs (HMRC) announced that Scottish salmon was, again, the UK’s most valuable food export in 2023. It’s also the UK’s top seafood choice. The impressive statistics have something to do with Mowi, that is the world’s largest salmon supplier and also provides a 40% of the country’s fresh salmon flows through the company’s primary processing plant in Fort William.
Salmon is low carbon food known for its healthy nutritional profile and salmon farming companies are recognized as best amongst global protein producers by the Coller FAIRR Protein Producer Index for key indicators that align with the United Nation’s Sustainability Development Goals. The Index has scored Mowi top of the ranking for the past five years in a row.
Post smolt and family genetics
And while the seas around the west coast of Scotland are an ideal place to grow salmon, rising ocean temperatures over the past decade have brought about unique challenges to the industry. Adapting to climate change is now regular business for farmers, and Mowi is setting a course with key strategic changes to its business. Mowi Scotland is actively developing two strategies to help salmon physically adapt to the environmental challenges: post smolt and family genetics.
In traditional salmon farming, smolts are moved directly from freshwater hatcheries and lochs to seawater sites where they are grown for 18 – 24 months before harvest. With post-smolt salmon, they are moved to sea when they are larger and more robust. This reduces the on-growing time at sea sites to 12 months, thus eliminating exposure to a second summer and the associated environmental risks.
This past month, Mowi’s farms in Loch Etive (previously growing trout under the Dawnfresh brand) received their first delivery of juvenile salmon. This group will be raised in the brackish waters of Etive and will be the first post smolts sent to sea later this year.
In the other hand, Mowi Scotland has made the important decision to develop a bespoke broodstock and egg facility at Ardessie, on the shores of Little Loch Broom. This new facility will boast state-of-the-art technology, including self-contained recirculating aquaculture systems and temperature control. For them, the key to this success is to build on the best qualities of each salmon generation.
This made in Scotland breeding program will enable genetics experts to select parent fish whose offspring will be most robust to the specific environmental challenges faced locally, and provide significant improvements in survival and biological performance.
