Invasion
Invasion Description
1st Record: Lopez Island (San Juan Islands)/WA/Spencer's Spit Lagoon, Puget Sound (1986, Gibson and Chia 1989a, type location, H. callidigenita)
Geographic Extent
Lopez Island (San Juan Islands)/WA/Spencer's Spit Lagoon, Puget Sound (1986, Gibson and Chia 1989a, type location, H. callidigenita); Rock Point, Lopez Island (San Juan Islands)/WA/Samish Bay, Puget Sound (1986, Gibson and Chia 1989a); Pierce County/WA/Gig Harbor, Puget Sound (Australian Museum 2006); British Columbia-WA/Boundary Bay (2011, Hanson et al. 2012)
Vectors
| Level | Vector |
|---|---|
| Alternate | Oyster Accidental |
| Alternate | Ballast Water |
Regional Impacts
| Ecological Impact | Competition | |
| The native H. vesicula is reported to have declined in areas invaded by H. japonica. (Hanson 2012). However, the details and locations of these observations were not given. | ||