Species Regional Summary
Magallana gigas
Pt. Conception to Southern Baja California ( NEP-VI )

Invasion History Vectors Impacts References

Invasion

Invasion Description

1st Recent Record: Island Yacht Anchorage, Los Angeles/CA/Los Angeles Harbor (2000, Cohen et al. 2002) Historical Records: CA/Newport Harbor (first planting 1932, stocked 1932-1940s, Carlton 1979) Few historical attempts were made to plant Magallana gigas in southern Calfiornia waters, because they were considered too warm. However, in recent years, settlement of large oysters, apparently C. gigas, has been noticed from Los Angeles Harbor to the Tijuana River estuary. These populations may be established- genetic work is needed to establish their identiy and origin (Cohen et al. 2002; Jeffrey Crooks, in de Rivera et al. 2005);  Before 2000, there were no reported records of Pacific oystes, but 31 since 2000 (Kornbluth et al. 2022).

Geographic Extent

CA/Mugu Lagoon (1932, California Department of Fish and Game, cited by Carlton 1979, 1 planting); Island Yacht Anchorage, Los Angeles/CA/Los Angeles Harbor (2000, Cohen et al. 2002; California Department of Fish and Wildlife 2014, 20 specimens); Long Beach/CA/Alamitos Bay (2012, Tronske et al. 2018); Huntington Harbor (2012, Tronske et al. 2018); Long Beach/CA/Colorado Lagoon (Burnaford et al. 2011, on an intertidal rock); CA/Newport Harbor (1932, 1940s, reproduction observed 1946, failed, Carlton 1979; 011, California Department of Fish and Wildlife 2014, 1 specimen; 2010-2013, Tronske et al. 2018; 2013, Obaza and Williams 2018); San Diego County/CA/San Elijo Lagoon (2014, Crooks et al. 2016); CA/Oceanside Harbor (Jeffrey Crooks, in de Rivera et al. 2005; established, Crooks, personal communication 2014; Crooks et al. 2016); Carlsbad/CA/Agua Hedionda Lagoon (2000, Cohen et al. 2002, established, Crooks, personal communication 2014; Crooks et al. 2016); San Diego County/CA/Batiquitos Lagoon (2014, Crooks et al. 2016); San Diego/CA/San Diego Bay (7 location, Tronske et al. 2018; 2013, Obaza and Williams 2018); Baja California/Mexico/Bahia San Quintin (1975, Naranjo-Garcia and Castillo-Rodriguez 2017, cultured); Baja California Sur, Mexico/Ojo de Liebre Lagoon, Pacific Ocean  CA/Ventura Harbor  to Tijuana estuary (2000-2020, Kornbluth et al. 2020);  30? 36’ S
Baja California/Mexico/Bahia de San Quintin to 26? 80’ S (Estero El Coyote (2000-2020, Kornbluth et al. 2022).

Vectors

Level Vector
Alternate Oyster Intentional
Alternate Ballast Water
Alternate Hull Fouling
Alternate Oyster Accidental

Regional Impacts

Economic ImpactFisheries
Substantial aquaculture operations for M. gigas occur in Bahia San Quitin, Baja California, Mexico (Rodriguez and Ibarra-Obando 2008).
 

References

Full Reference List for Magallana gigas

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