In February, Mowi started production at the new hatchery in Northern Norway.
1.5 million juvenile have died after an incident at the beginning of May.
Mowi has notified the Food Safety Authority about the incident on the of May 6, wrote Nordlys.
The fish farmer informs the newspaper that the cause is still unknown, but that they are working with several laboratories and suppliers to find out.
Nordlys claim they have spoken to sources, who say the fish probably died of acute sulfur poisoning. The old hatchery Mowi had was a flow-through hatchery, while the new hatchery uses RAS technology.
This is not the first time that there have been problems at the hatchery, which cost EUR 37 million (NOK 400 million).
In the past, it has also caught fire. SalmonBusiness has tried to get a comment from Mowi’s communications manager, Eivind Nævdal-Bolstad, but has so far not been able to get through.