The Danube and its tributaries are being colonised by non-native species, (such as the zebra mussla Dreissena polymorpha, the river nerite Theodoxus fluviatilis, or the Asian clam Corbicula flumines) due to the increasing interconnection of various European water bodies by canals and other waterways designed to facilitate inland navigation across the continent. The increased volume of intercontinental shipping has also facilitated the establishment of several exotic animal species from still further afield.
It is still difficult to assess all the potential pressures and impacts resulting from the invasions of these alien species. However, alien species are very likely to become even more significant in the future, as the importance of the Danube as an international waterway increases.
The Danube River Basin Managment Plan includes a chapter on invaseve species.
According to research of the UBA Austria "Neobiota in Austria", relatively few of the region’s invasive species cause any serious ecological problems in river floodplain forests and wetland areas nearby rivers.
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