The origin of the Bay barnacle Amphibalanus improvisus is unclear, and therefore referred to by many scientists as cryptogenic. It is a typical fouling species that distributes itself by clinging to ship hulls.In Belgium, living Bay Barnacles were first reported in 1895. There were even specimens found in archaeological materials dating back to the 17th century. This barnacle can compete with local species for food and space, but it can also influence the occurrence of algae, as seen in the Baltic Sea.
- VLIZ Alien Species Consortium http://www.marinespecies.org/aphia.php?p=sourcedetails&id=132969