Invasion
Invasion Description
1st Estuarine Record: CA/Sacramento-San Joaquin Delta (1961, Wang 1985; Cohen and Carlton 1995); 1st Watershed Record: CA/Sacramento-San Joaquin watershed (1959, Central Valley reservoirs, Cohen and Carlton 1995; Dill and Cordone 1997)
Geographic Extent
CA/Sacramento-San Joaquin watershed (1959, Central Valley reservoirs, Cohen and Carlton 1995; Dill and Cordone 1997); CA/Sacramento-San Joaquin Delta (Wang 1985; Cohen and Carlton 1995); CA/Suisun Marsh (Meng et al. 1994 (Meng et al. 1994; Matern and Moyle 2003); Feyrer et al. 2003); CA/Elkhorn Slough-Salinas River (Kukowski 1972); CA/Petaluma and Napa Rivers, San Pablo Bay (Leidy 2007); CA/Coyote Creek and Guadalupe River (Leidy 2007); CA/Alviso Slough, south San Francisco Bay (Mehja et al. 2008)
Vectors
| Level | Vector |
|---|---|
| Probable | Fisheries Accidental (not Oyster) |
Regional Impacts
| Ecological Impact | Competition | |
| Threadfin Shad in the San Francisco Bay Delta showed a close dietary overlap (primarily planktonic copepods) with the endangered Delta Smelt (Hypomesus transpacifricus (Feyrer et al. 2003). | ||
| Ecological Impact | Food/Prey | |
| Threadfin Shad in the San Francisco Bay Delta were a major prey item for Striped Bass (Morone saxatilis), Largemouth Bass (Micropterus salmoides) and Sacramento Pikeminnow (Ptychocheilus grandis) (Nobriga and Feyrer 2007; Nobriga and Feyrer 2008; Feyrer et al. 2009) | ||
| Economic Impact | Fisheries | |
| Threadfin Shad were stocked in the San Francisco Bay Delta as a forage fish for introduced gamefish, especially Striped and Largemouth Bass. Although it has undergone recent declines, it still supports major sport fisheries for Striped Bass and Largemouth Bass (Dill and Codone 1997; Feyrer et al. 2009). | ||