Asian carp, which was imported into the United States in the 1970s to clean algae in commercial ponds, spilled into the freshwater system and flourished. It thrived so well that some of the fish ...

as well as carp, eel, and salmon from the Vistula River. Salmon was served as one of the Christmas Eve dishes to King Jan III Sobieski in 1695, for example. Foreigners visiting Poland noticed that the ...