Seafood magnate Gustav Witzoe, owner and top executive at SalMar and one of Norway's richest individuals, says his countrymen's lack of interest in salmon farming jobs is "puzzling," particularly given the rate of unemployment in the country.

Two-thirds of the roughly 750 employees working at Oslo-listed salmon farmer SalMar's processing facility Innovamar in Froya, Norway, for example, are foreign.

The salmon industry is continually looking for vacancies, but Norwegian nationals rarely put up their hand.