Invasion
Invasion Description
Recent 1st Record: Dumbarton Railway Bridge/CA/South San Francisco Bay (2000, Andy Chang, personal communication, Goodwin et al. 2011; Ruiz et al. unpublished data, possibly established populations). Since 2000, the settlement of large oysters, apparently M. gigas has been observed in San Francsco Bay. In 2006, more than 100 of these oysters were removed in a control attempt (2006, USGS Center for Aquatic Resource Studies 2006). Shell isotope studies indicate that at leas two successful cohorts were established (Goodwin et al. 2011). Historical Records: 1st planting 1932, commercial plantings 1932-1939 (Carlton 1979).
Geographic Extent
Dumbarton Railway Bridge/CA/South San Francisco Bay [Population status unknown, Removal attempts](2000, Andy Chang, personal communication; Ruiz et al. unpublished data); eastern shore of South Bay from Dumbarton Point to Coyote Slough/CA/San Francisco Bay (2006, USGS Center for Aquatic Resource Studies 2006). Historical Records: 1st planting 1932, commercial plantings 1932-1939 (Carlton 1979).
Vectors
| Level | Vector |
|---|---|
| Alternate | Ballast Water |
| Alternate | Hull Fouling |
| Alternate | Oyster Intentional |
Regional Impacts
| Economic Impact | Fisheries | |
| Commercial rearing of M. gigas took place in San Francisco Bay from 1932 to 1939, when the company involved went out of business (Barrett 1963). | ||
| Ecological Impact | Parasite/Predator Vector | |
| Parasite-Predator vector- Although M. gigas has not become definitely established in San Francisco Bay, its introduction has been a possible/probable vector for a number of oyster foulers or predators, including, the parasitc copepod Mytilicola orientalis (widespread), the mussel Musculista senhousia, the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus and Styela clava (Carlton 1979; Cohen and Carlton 1995). | ||