The non-indigenous freshwater fishes of Poland: Threats to the native Ichthyofauna and consequences for the fishery: A review

Abstract

This paper reviews the history, current state, tendencies, and perspectives of the fish introductions in Poland, as well as the consequences for the native ichthyofauna. The last 800 years witnessed attempts at introducing 37 fish species to territories the of present-day Poland; 19 of them still occur in inland waters of the country. The introductions (deliberate and accidental) reached their peak within 1964-2008, when as many as 24 alien fish species (64.5% of all "acquisitions") were introduced. In most cases, the negative effects on the aquatic environment, native fish species, and other aquatic organisms were noted. Alien helminth parasites (Monogenea, Digenea, Cestoda, and Nematoda), pathogenic fungi, and higher organisms (bivalves, fishes) have been introduced along with the fishes. In terms of the increased fish production and economic profits the aquaculture has been the only section of fisheries that has benefited from acquiring new fish species. Further, detailed studies on the effect of alien species on the native ichthyofauna are necessary.