Alien fish and crayfish species in Hellenic fresh waters and
aquaculture
The diversity of ichthyofauna in Hellenic freshwaters is highlighted by the presence
of 161 species. This actually represents 27.8% of the total fish species
recorded in European freshwater, including both native and introduced species,
suggesting that Greece represents a ‘hot spot’ for biodiversity. The introduction
of alien species for restocking, the aquarium trade and aquaculture was responsible
for the deliberate or accidental release of alien specimens into open waters
and in some cases for establishing populations. In contrast, commercially valuable
alien species (e.g. salmonids, cyprinids and more recently sturgeons)
generated significant income to individuals, companies and to the national
economy. This paper aims to review the situation regarding the presence of
alien fish and crayfish species in Hellenic freshwaters and in particular in aquaculture
and to flesh out issues concerning their aquaculture potential.