Nordlaks Dragnes site, Hadsel municipality, Norway, where infectious salmon anemia (ISA) was detected.
Photo: Nordlaks
Norwegian salmon farming company Nordlaks has announced it has taken the decision to cull 1.9 million salmon at one of its farming sites in Nordland county, following detection of the infectious salmon anemia (ISA) virus in water samples taken from the site.
The company released a statement indicating the cull was planned to take place on 9 June. Nordlaks' Dragnes location in Hadsel had seen "slighly elevated mortality" in one of its pens, prompting samples to be taken for analysis by Mattilsynet, the Norwegian Food Safety Authority.
The presence of ISA was confirmed on 5 June, and while final results were not immediately available, the company said it had decided "to decontaminate the entire site".
This is the second time in a matter of weeks that Nordlaks has been forced to cull fish. The company previously announced at the end of April that it had undergone a "full emergency alert" due to a harmful algal bloom affecting its Fornes site in Lødingen municipality.
"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," said Nordlaks CEO, Eirik Welde, via a Norwegian language announcement.
The company said the fish in question were put into the Dragnes facility in autumn 2024, and had grown to an average size of 850 grams.
ISA is a serious and contagious viral disease affecting salmonids, which is monitored by Norwegian authorities. The virus is not transmissable to humans, but is a significant problem for fish health and welfare, and is highly costly for fish farmers.
Once ISA is confirmed at a farming site, the Norwegian Food Safety Authority imposes a restriction zone of 10-20 kilometers to prevent further spread of the disease, and typically also orders all of the fish to be culled.
The disease can be spread from site to site through transportation of fish and roe, but also from service vessels themselves. Several outbreaks of the disease were reported across Norway during the summer months last year, prompting Norwegian veterinary associations to launch a new set of guidelines for better hygiene control of aquaculture service vessels.