Invasion
Invasion Description
1st Record: CA/Tomales Bay (1941, Carlton 1979)
Geographic Extent
Bodega Bay/CA/Bodega Harbor (2007, Weiskel et al. 2007; Houle 2011, established); CA/Tomales Bay (1941, Carlton 1979; Byers 1999); CA/Drakes Estero (1932, Byers 1999); CA/Bolinas Lagoon (1955, Byers 1999); Loch Lomond Marina, San Rafael/CA/San Francisco Bay (Prado 7-17-2006; established, Chela Zabin, personal communication, 4/22/13); CA/Elkhorn Slough (1955, Carlton 1979, Byers 1999, ; dramatic population decline at many sites in Elkhorn Slough)
Vectors
| Level | Vector |
|---|---|
| Probable | Oyster Accidental |
Regional Impacts
| Ecological Impact | Competition | |
| The native snail Cerithidea californica declined an average of 27% over a 3-year period in coexisting California populations (Byers 1999). In experiments, Batillaria attramentaria was superior to C. calfornica in food conversion (Byers 2000a), hypoxia tolerance (Byers 2000b), and parasitism resistance (Byers and Goldwasser 2002). The native snail Cerithidea californica is absent in Elkhorn Slough, but may have been previously present, based on sketchy historical records and its presence to the north and south (Byers 1999). Based on observations in three other estuaries, B. attramentaria may have eliminated Cerithidea californica from Elkhorn Slough (Byers 1999). | ||