Aquaculture facility in Norway.
Photo: Norwegian Food Safety Authority (Mattilsynet).
The Norwegian Food Safety Authority (Mattilsynet) has announced that it is establishing four restriction zones in the area of Vesterålen, Nordland County, following the discovery of five cases of Infectious Salmon Anemia (ISA) at aquaculture facilities in the area.
According to the authority, two of the most recent cases will be subject to surveillance zones that are larger than usual, to increase the likelihood of early detection and help prevent further transmission.
Mattilsynet said the Norwegian Veterinary Institute has examined samples from the affected sites but has not yet identified the source of the outbreak. The institute reports that genetic analysis of the viruses suggests similarities between strains found in multiple locations. Based on this, officials suspect that the infection may have spread locally, potentially via water flow or shared equipment.
Geir Arne Ystmark, who leads the northern division of the aquaculture inspection unit, stated: “The farmers have acted quickly and effectively after the detection of ISA. Rapid notification, implementation of measures and good cooperation are important to limit the spread of infection.”
Areas from Børøyfjorden and further north do not fall within the new surveillance zones, Mattilsynet said. However, the Authority is urging fish farmers in those locations to carry out voluntary monitoring, even where testing for ISA is not mandated.
According to the agency, such proactive measures could support earlier detection if the virus spreads beyond the designated zones.
All individuals travelling through the region or involved in aquaculture-related activities are reminded to take precautions to minimise the risk of spreading the disease. Further details, including an overview of ISA cases, are available on BarentsWatch.
The notification from Norwegian authorities follows Norwegian salmon farming company Nordlaks' announcement last month it had decided to cull 1.9 million salmon at one of its farming sites in Nordland county, following detection of the ISA virus in water samples taken from the site.
"It is a sad decision to make, but we must take action to prevent the spread of the disease. The recent algal bloom, and now the ISA outbreak, are greatly affecting our operations. We are now working to reduce the consequences," Nordlaks CEO Eirik Welde said at the time, via a company statement.