In 2001, Frode Arntsen was working as a teacher at a Norwegian secondary school.

While he still lives in the same coastal region -- Trondelag, in the middle of Norway -- today he heads up salmon farming company SalMar, managing 2,500 employees and the sprawling operations of the world's second-largest salmon farming company.

The dramatic career shift was accidental. He was asked, out of the blue, about interviewing for a position as production manager at a small factory belonging to salmon farmer Leroy Seafood's Midnor division.