Species Regional Summary
Geukensia demissa
Northern California to Mid Channel Islands ( NEP-V )

Invasion History Vectors Impacts References

Invasion

Invasion Description

1st Record: CA/South San Francisco Bay (1894, Stearns 1899, cited by Carlton 1979)

Geographic Extent

CA/Tomales Bay (Fairey et al. 2002); China Camp/CA/San Pablo Bay (2005, Robinson et al. 2011); CA/South San Francisco Bay (1894, Stearns 1899, cited by Carlton 1979); San Leandro Marina/CA/South San Francisco Bay (Cohen et al. 2005); Redwood city/CA/South San Francisco Bay (Miller et al. 2007); CA/Morro Bay (Needles 2007; Needles and Wendt 2012, present in a 1986 survey but not detected in 2005)

Vectors

Level Vector
Probable Oyster Accidental

Regional Impacts

Ecological ImpactHabitat Change
Closing shells can trap chicks and sever toes of adult endangered California Clapper Rails (Rallus longirostris obsoletus) in salt marshes (Carlton 1979; Cohen and Carlton 1995).
 
Ecological ImpactFood/Prey
Geukensia demissa comprised 57% of the diet of the endangered California Clapper Rail (Rallus longirostris obsoletus) (Moffitt 1941, cited by Cohen and Carlton 1995).
 

References

Full Reference List for Geukensia demissa

  • Nemesis (current)
  • Marine Invasions Lab
  • Partner Portals
    Nemesis California Panama Galapagos Cocos Island NP JTMD
    Archived Projects
    Chesapeake
  • Browse Species
    Taxonomic Groups All Species
  • Browse Regions
    States
    Alaska
    Bioregions & Bays
  • News
  • login

Direct questions and comments to nemesis@si.edu.

©