Invasion
Invasion Description
1st record: CA/Sacramento-San Joaquin Delta (1959, Reigel 1959, cited by Cohen and Carlton 1995) 1st Watershed record: San Francisco County/CA (1898, Kimsey 1982, cited by Cohen and Carlton 1995)
Geographic Extent
Yount Cross Road E of Yountville/CA/Napa River (1975. USNM 176805, US National Museum of Natural History 2007, in upper Napa watershed); CA/Sacramento-San Joaquin Delta (1959, Reigel 1959, cited by Cohen and Carlton 1995); CA/San Francisco County (Kimsey 1982, cited by Cohen and Carlton 1995); Mill Valley/CA/Widow Reed Creek, Richardson bay drainage (1975, USNM 176836, US National Museum of Natural History 2007)
Vectors
| Level | Vector |
|---|---|
| Probable | Fisheries Intentional |
Regional Impacts
| Economic Impact | Fisheries | |
| Pacifastacus leniusculus is the major crayfish species caught in the San Francisco Bay Delta, supporting a fishery of 250 tons annually (Cohen and Carlton 1995). | ||
| Ecological Impact | Competition | |
| Pacifastacus leniusculus may have contributed to the extinction of a native crayfish (P. nigrescens, Sooty Crayfish), and is considered to be a competitor threatening another native crayfish, P. fortis (Shasta Crayfish) (Cohen and Carlton 1995). | ||