Invisible to the human eye, the Spironucleus salmonicida parasite has plagued Grieg Seafoods' northern Norway salmon farming operations since 2022.
The organism has cost the Grieg NOK 900 million (€79.5 million/$86.1 million) over that time, according to the company's latest financial report. It is expected to continue impacting costs into the middle of this year.
The parasite caused 36 percent of Grieg's Finnmark fish to fall below "superior" quality status, heavily impacting price achievement in the fourth quarter.
The parasite caused a similar quality downgrade to 14 percent of Grieg's fish from its southern Norway farms - which were impacted by other problems - and 3 percent from its Canadian operations.
