Invasion

Invasion Description

1st Record: Knappton, Pacific County/WA/Columbia River (1938, Counts 1986)

Geographic Extent

: Knappton, Pacific County/WA/Columbia River (1938, Counts 1986); Sauvie Island, Portland/OR/Columbia River (1943, USGS Nonindigenous Aquatic Species Program 2007); Bonneville Dam-Astoria/OR-WA/Columbia River (1949, USGS Nonindigenous Aquatic Species Program 2007); Longview/WA/Tidal Drainage Ditch (4/18/2002, Sytsma et al. 2004, 46.1505, -123.0145); Willow Grove Boat Launch/WA/Columbia River (4/18/2002, Sytsma et al. 2004, 46.1738, -123.0853); Kalama, Sportsmens Club Road Boat Launch/WA/Columbia River (6/27/2002, Sytsma et al. 2002, 446.0392, -122.8745); (Sytsma et al. 2004); Woodland/WA/Burke Slough (4/18/2002, Sytsma et al. 2004, 45.9251, -122.7970); OR/Knappa Slough, Columbia River (6/28/2002, Sytsma et al. 2004, 46.1867, -123.5917); Karlson Island/OR/Columbia River (6/28/2002, Sytsma et al. 2004, 46.2038, -123.6219); Russian Island/OR/Columbia River (6/28/2002, Sytsma et al. 2004, 46.1932, -123.6131); Marsh Island/OR/Columbia River (6/28/2002, Sytsma et al. 2004, 46.2073, -123.5882); Astoria Yacht Club (4/17/2002, 7/8/2002, Sytsma et al. 2004,46.1705, -123.8363, 0.75ppt, 6ppt); Cowlitz County/WA.Martin Slough, Columbia River (1999, Wilson and Partirdge 2007); Vancouver/WA/Columbia River (2005-2013, larvae comprised a mean of13% of zooplankton individuals); Kalama and Blurock/WA/Columbia River estuary (Henricksen and Bollens 2021)