Further expansions of the Asian tunicate Styela clava Herdman 1882 in Ireland

The first records of Styela clava are reported from the northern coasts of Ireland from two sheltered inlets in 2008. On the south coast, high densities were found associated with mussel longlines in a shallow bay and remained abundant in 2009. There is a potential for expansion of the species that may impact upon aquaculture installations in Irish shallow waters. The distribution of the species in Ireland is reviewed.