Dreissena polymorpha

Since the mid-1980s, the Ponto-Caspian zebra mussel Dreissena polymorpha has been spreading throughout eastern North America. It has caused a wide variety of ecosystem impacts, including substantial changes to the diversity and abundance of benthic invertebrate communities in lakes and rivers (Ward & Ricciardi 2007; Ricciardi et al. 1995, 1996, 1997, 1998).  It continues to expand its range, having been discovered in California in 2008.