Is Ballast Water a Major Dispersal Mechanism for Marine Organisms?

More than 1,000 non-indigenous aquatic species, ranging from unicellular algae to vertebrates, have been found in European coastal waters, including navigational inland waterways for ocean-going vessels and adjacent water bodies. Approximately half of all non-indigenous species recorded to date have established self-sustaining populations (Gollasch 2006). These introductions are of high concern, as many cases have caused major economical or ecological problems (Chaps. 13-19).

Species are introduced unintentionally (e.g. with ships) or intentionally (e.g. for aquaculture purposes and re-stocking efforts). In shipping, the prime vectors for species transportation are ballast water and in the hull fouling of vessels. Further, a considerable number of exotic species migrates through man-made canals. Examples are the inner-European waterways connecting the Ponto-Caspian region and the Baltic Sea. Also, the Suez Canal “opened the door” for Red Sea species migrations into the Mediterranean Sea and vice versa