Range extensions of Ponto-Caspian aquatic invertebrates in Continental Europe

Abstract

The dispersal of Ponto-Caspian aquatic invertebrates outside theirhistoric geographical range during the past 200 years was mainlycaused by the construction of canals between previously separatedbiogeographic regions and to unintentional transport via ballastwater of vessels. In addition, intentional introductions outsidetheir native range facilitated further spread of Ponto-Caspian species.Since the beginning of 1990 their spread has been accelerated bythe opening of the Main-Danube Canal in southern Germany. Four mainmigration corridors can be distinguished: a northern corridor connectingthe Rivers Don and Volga with the Baltic Sea, a north central corridor,connecting the River Dnieper with the Baltic Sea region and the RiverRhine basin, a south western corridor, connecting the River Danubewith the Rhine and neighbouring basins, and a southern corridor throughthe Mediterranean.