Maritime canals dissolve natural barriers to the dispersal of marine organisms, thus providing novel opportunities for natural dispersal, as well as for shipping-mediated transport. The introduction of alien species has proved to be one of the most profound and damaging of anthropogenic deeds - with both ecological and economic costs. This book is the first to assess the impacts of the world's three principal maritime canals - the Kiel, the Panama, the Suez - as invasion corridors for alien biota. These three canals differ in their hydrological regimes, the types of biotas they connect, and in their permeability to invasions.