Mowi, the world's largest salmon farmer, saw earnings at its Scottish operations drop by almost 70 percent as low growth and high mortalities took their toll.
CEO Ivan Vindheim blamed the losses in part on jellyfish outbreaks around Skye and the Western Isles.
As a result of the losses, Mowi was forced to slash its harvest guidance by 17 percent to 50,000 metric tons for this year, and reduced its projections for next year to 65,000 metric tons.
Micro jellyfish bloom events are increasingly common as oceans warm.
