Invasion

Invasion Description

1st Record: 'widespread in the lower bays of the basin, in brackish as well as freshwater'/OR-WA/Columbia River estuary (1999, Sytsma et al. 2005)

Geographic Extent

Klatskanie, Clatsop County/OR/Youngs River (7/9/2002, Sytsma et al. 2005, USGS Nonidigenous Species Program 2011, 1 PSU); Sauvie Island-Gilbert River Boat Ramp, Portland/OR/Columbia River (6/26/2003, Sytsma et al. 2005, USGS Nonidigenous Species Program 2011, 0 PSU); Willow Grove boat launch, Longview/WA/Columbia River (4/8/2002, Sytsma et al. 2005, USGS Nonindigenous Species Program 2011, 0 PSU); Ilwaco Harbor/WA/Baker Bay, Columbia River (7/9/2002, Sytsma et al. 2005, USGS Nonidigenous Species Program 2011, 10 PSU)