Two new genetic markers that indicate greater resistance to a bacterial infection in Atlantic salmon have been identified by a team of aquaculture researchers in Scotland.
The research team has been exploring the genetics that determine whether fish are resistant to Flavobacterium psychrophilum, a bacteria that can lead to health issues in salmon fry.
Its findings are expected to pave the way for selective breeding programs, which could boost the health and welfare of farmed salmon by breeding new fish from parents that possess the genetic resistance markers and should therefore have increased resistance to the bacteria.
The project has been backed by the Sustainable Aquaculture Innovation Centre (SAIC) and led by AquaGen Scotland, with partners from the University of Stirling’s Institute of Aquaculture, DawnFresh Farming, and Cooke Aquaculture Scotland.
To identify the two genetic markers, more than 4,000 fish from AquaGen were tested for more than 70,000 genetic markers using a specially designed lab-based model, which mimics the natural infection route.
The next stage of the research program is to conduct field trials at one of Cooke Aquaculture’s sites using salmon eggs specifically selected by AquaGen.
It is hoped that in the event of a natural outbreak of the bacterial disease, these fish can be tested to validate the effect of the genetic markers.
“Continual improvements in fish health and welfare are priorities for the aquaculture industry, to which robust stock suited to the farmed environment make an important contribution. Genetic markers for disease resistance, such as those discovered through this SAIC-funded project, are valuable tools that can and will be immediately employed in breeding work,” AquaGen Managing Director Andrew Reeve said.
SAIC CEO Heather Jones said the interim results of the R&D project were “highly encouraging” and point toward a new, sustainable approach to tackling a common health issue reported in young salmon.
“One of the most valuable outputs of collaborative innovation projects is the wealth of knowledge that can be shared across the entire sector and findings like this have the power to make a big difference to fish health and welfare,” she said.
SAIC highlighted that flavobacteriosis – the disease caused by the bacteria – can be a particular threat to smaller, juvenile fish and is a widespread challenge for the aquaculture sector, with infections also reported in Chile, Norway, and Canada.
The center said current prevention and treatment programs are limited and vaccination by injection cannot be used due to the size of the fish. It also suggested that as the sector continues to move away from antibiotic treatments, a genetic breakthrough could hold the key.
“Flavobacteriosis is known to be problematic for salmonid culture in freshwater globally for decades. This project has shown how fruitful it can be to combine the expertise of academic and industry researchers to address a complex and economically important disease,” Rowena Hoare, an Institute of Aquaculture research fellow, said.
Photo courtesy of the Sustainable Aquaculture Innovation Centre
