 Enkhuizen is called 'Haringstad' (Herring Town) and was an important fishing port for centuries until the Zuiderzee was closed off in 1932 by the construction of the Afsluitdijk.The fishing grounds were now fresh-water and the fish changed from fish like herring and anchovy to eel, smelt and red perch.Nowadays, eels are rare in the IJsselmeer; the most probably causes are water pollution, and the industrial fishing of their offspring ("glass eels" due to their transparency) during their travels back to Europe from the eels' breeding waters in the Sargasso Sea for rearing in land-based containers.