A risk assessment of biological invasions in the inland waterways of Europe: the Northern Invasion Corridor case study

INTRODUCTIONInland waterways have provided opportunities for the spread of aquaticnon-indigenous species (NIS) for many centuries (reviewed in Ketelaars 2004,Galil and Minchin 2006, Galil et al. 2007). Canals connecting different riverbasins have allowed for range extensions of many species, either by activemovement and/or by ship transport. Over the past century, the potential forspecies to expand their range has been enhanced due to increasing trade andthe construction of canals. The waterways occur at low altitudes and presentlythe main European corridor routes consist of an interlinked network of 30main canals with more than 100 branches, and more than 350 ports exist inlow-altitude Europe.The European Agreement on Main Inland Waterways of InternationalImportance (AGN) was signed under the framework of the United Nations639