Invasion

Invasion Description

1st Record: Sweden/Lake Vanern (1954, Drotz et al. 2010, rare and sporadic captures until 1990s, now common during population pulses) Genetic studies indicate that Lake Vanern populations populations are derived from those breeding in the Elbe River and other North Sea tributaries (Czerniejewski et al. 2012).

Geographic Extent

Sweden/Lake Vanern (1954, Drotz et al. 2010, Drotz 2012, rare and sporadic captures until 1990s, now common during population pulses); Sweden/Lake Glafsfjorden (1961, Drotz et al. 2010, northernmost inland record)