Invasion
Invasion Description
1st Estuarine Record: CA/Sacramento-San Joaquin Delta (1961, Cohen and Carlton 1995) 1st Estuarine Record: CA/Sacramento-San Joaquin Delta (1961, 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/Drake's Estero (Cohen and Carlton 1995, sporadic marine migrant); 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); Yoklavich et al. 1991); CA/Pajaro River, Salinas River reservoirs (Center for Aquatic Resource Studies 2009)
Vectors
| Level | Vector |
|---|---|
| Probable | Fisheries Intentional |
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 (Feyerer 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 watershed 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 2007; Feyrer et al. 2009). | ||