Invasion
Invasion Description
1st Record: WA-OR/Columbia River Estuary (1999, Sytsma et al. 2004);
Geographic Extent
OR-WA/Columbia River estuary (1999, Sytsma et al. 2004); Portland/OR/Crane Slough, Columbia River (1999, Sytsma et al. 2004); Woodland/WA/Burke Slough (2002, Sytsma et al. 2004); Russian Island/OR/Columbia River (2002, Sytsma et al. 2004); Wallooskea/OR/Youngs River (2002, Sytsma et al. 2004); WA/Grays River 2002, Sytsma et al. 2004); OR/Blind Slough, Columbia River (2002, Sytsma et al. 2004) (Completely replacing P. inopinus (Sytsma et al. 2004; Dexter et al. 2-05); Vancouver/WA/Vancouver Lake (6/2006, Lee et al. 2016, tidal Coumbia River tributary lake)
Vectors
| Level | Vector |
|---|---|
| Probable | Ballast Water |
Regional Impacts
| Ecological Impact | Competition | |
| In the Columbia River, Pseudodiaptomus forbesi, by 2002, has largely replaced a previous invader, P. inopinus (Sytsma et al. 2004; Cordell 2008). Psudodiaptomus forbesi has a substantial period of temporal overlap and potential competition with the native northeast Pacific form of 'Eurytemora affinis' in the Columbia estuary (Bollens et al. 2012). | ||
| Ecological Impact | Food/Prey | |
| In experiments, 3 species of native fishes (Chinook Salmon- Oncorhynchus tschawytscha, Three-spined Stickleback- Gasterosteus aculeatus, and Northern Pikeminnow- Ptychocheilus oregonensis) consumed P. forbesi together with native copepods, but salmon and pikemnnows showed a preference for native cladocerans over copepods (Adams et al. 2015). | ||