Invasion

Invasion Description

1st Record: River Mile 12-River Mile 23/OR-WA/Columbia River estuary (1990, Cordell et al. 1992)

Geographic Extent

River Mile 12-River Mile 23/OR-WA/Columbia River estuary (Cordell et al. 1992), largely replaced by P. forbesi by 2002 (Cordell in Sytsma et al. 2005); OR/Youngs River Estuary (1991, Cordell and Morrison 1996). Vancouver/WA/Columbia River (not detected in sampling, 2005-2013, Dexter et al. 2013, in tidal freshwater or brackish portions of the estuary), apparently replaced by P. forbesi)