Stockfish — wind-dried, unsalted fish (mainly cod) — is Norway’s biggest export, and has been for many hundreds of years.  Between February and May, cod is fished on the open ocean, cleaned, and hung to dry along the shore on wooden trestles called hjell.  The cold air prevents the fish from spoiling, and over several months, the fish will slowly dehydrate and a fermentation by cold-acclimatized bacteria will take place, preserving the fish.  Stockfish is exported all over the world and will keep for several years if it has been properly preserved using this method.  While I was in Lofoten, the first catches of the season were coming in and were being hung to dry throughout the islands.