Invasive species

Abstract

Aquatic ecosystems are exposed to the influence of non-indigenous (non-native, alien or exotic) species. The Danube River is not an exception. Non-indigenous species were recorded among algae, aquatic macrophytes, macroinvertebrates and fish. Also, introduction of allochthonous fish species caused introduction of new fish parasites (Djikanovic et al. 2012). The pressure caused by biological invasions has already been documented for the Danube River and its main tributaries (Literáthy et al. 2002, Csányi 2002, Csányi & Paunović 2006, Liška et al. 2008). The Danube River is a part of the Southern Invasive Corridor (Panov et al. 2009). The Southern Corridor links the Black Sea with the North Sea basin via the Danube-Main-Rhine waterway including the Main-Danube Canal. Thus, the Danube River is a part of one of the main routes for the migration of aquatic organisms in Europe, including the non-native species and consequently the river is exposed to high potential pressure from biological invasions. The aim of this chapter is to present the state of the art in respect to presence of non-native aquatic species (aquatic macrophytes, aquatic macroinvertebrates and fish) in the Danube River based on Joint Danube Survey 3 (JDS3) results. Also, the present situation is compared with prior, based on previous Danube Surveys.