Mortality figure rises to half a million at Mowi Norway fish farm
Published
The number of salmon now known to have died at a Mowi site in Norway has risen from 140,000 in the first three weeks of November to 496,000 for the full month.
Documents seen by Fish Farming Expert’s Norwegian sister site, Kyst.no, show that more than 140,000 farmed salmon died at the Krabbestig site in the period from November 1 to 21, 2025.
This is revealed in an inspection report from the Norwegian Food Safety Authority (Mattilsynet), carried out after the company reported increased mortality related to gill problems. Mattilsyent has since told Kyst.no that the total number of dead fish at the site was 496,460 for November.
The Krabbestig site is located in Kinn municipality, in Vestland county.
Some cages at the site had higher mortality rates than others, with one pen recording mortality of more than 40%. According to the report, the mortality is linked to both acute and chronic gill problems.
Unacceptable situation
During the inspection on 25 November, Mattilsynet observed fish with respiratory problems, and autopsied fish showed pinpoint bleeding on the gills. It considered the situation to be unacceptable from a fish welfare perspective and ordered Mowi to implement measures to ensure proper operations at the site.
At the same time, it was revealed that the location was above the permitted limit for sea lice. In week 48, an average of 4.31 adult female lice per fish was reported. Mattilsynet therefore also ordered measures to get below the lice limit, with possible culling as a consequence if the requirements were not met.
Harvesting the site
In a comment to Kyst.no, Mowi said that the company had decided to harvest the remaining fish at the site.
“Despite improvement in recent weeks, we have decided to harvest the locality Krabbestig out of consideration for fish welfare,” wrote communications director Morten Bertelsen.
He further stated that the company does not yet have a definitive explanation for the cause of the problems.
“We have indications that a water-borne agent may have had a negative impact in the area, but there is currently no final conclusion on the cause of the gill problems,” wrote Bertelsen.
'Serious incident'
Aud Skrudland, head of department in Mattilsynet’s aquaculture inspection division, told Kyst.no that this is a serious incident where animal welfare has significantly deteriorated.
“Therefore, we have followed up closely with clear decisions to ensure animal welfare. It is important that the farmer finds the root cause of the high mortality so that similar situations do not occur again,” she said.
