Recirculating aquaculture systems (RAS), known for their efficient water use and controlled environment in Atlantic salmon (Salmo salar L.) farming, may be threatened by airborne pathogen transmission.
A joint research team from the National Reference Laboratory for Fish and Animal Diseases, the Faroese Food and Veterinary Authority, and the University of Copenhagen's Department of Veterinary and Animal Sciences has provided the first field evidence that Infectious Pancreatic Necrosis Virus (IPNV), a viable Atlantic salmon virus, can become aerosolised within commercial RAS facilities.
The findings come from investigations at two commercial salmon farms in the Faroe Islands, where researchers analyzed pathogen presence through aerosol, water, and fish swab samples.
The researchers state that while horizontal transmission through water in RAS is well known, the role of aerosols in spreading pathogens has been mostly overlooked.
Multiple salmon pathogens were detected in aerosol samples. At one farm, a sequential infection pattern was recorded:
All these pathogens were also found in the biofilter room, with additional presence in tank and degassing areas.
This study highlights the importance of considering aerosol transmission in RAS biosecurity protocols to better manage disease risks in salmon farming.
The Infectious Pancreatic Necrosis Virus (IPNV) can become aerosolised in commercial RAS environments, suggesting airborne pathways for infection.
Author's summary: This research unveils aerosol transmission as a critical, previously underestimated route for virus spread in salmon recirculating aquaculture systems, urging enhanced biosecurity measures.