Invasion
Invasion Description
1st Record: CA/Sacramento-San Joaquin Delta (1983, Cohen and Carlton 1995)
Geographic Extent
CA/Sacramento-San Joaquin Delta, Suisun Bay (Cohen and Carlton 1995); Bethel Island/CA/Sacramento-San Joaquin Delta (1993, Cohen and Carlton 1995); Martinez/CA/Suisun Bay (1993, Cohen and Carlton 1995); Brown’s Island, CA/Sacramento-San Joaquin Delta,38.0829N,1218529W (1998, Toft et al. 2003); cargo ship 'Florikan'/CA/Suisun Bay (Llanso et al. 2011); Fresh-Brackish-Sandy (Delta mean salinity 0.1 PSU) to Main Estuarine (Suisun-San Pablo, Mean Salinity 16.1 PSU), highest abundance at Fresh-Brackish-Muddy Zone (0.7 PSU, Lee et al. 2003); CA/South Francisco Bay (2012-2013, Jimenez et al. 2017, on hard and soft substates)
Vectors
| Level | Vector |
|---|---|
| Probable | Ballast Water |
Regional Impacts
| Ecological Impact | Food/Prey | |
| Gammarid amphipods, probably dominated by G. daiberi were not present in the diet of juvenile Striped Bass (Morone saxatilis) in the San Francisco estuary in 1963-64, but were found in 34-43% of fish sampled in 2001 and 2003. The comparatively large size of these prey compared to other invertebrates suggests that the invasion had a significant impact on the diet of young Striped Bass (Nobriga and Feyrer 2007). Stable isotope analyses indicate that gammarid amphipods are a major component of the diet of many fishes, providing at least 50% of the muscle carbon of 5 species of introduced fishes and 2 native fishes (Grimaldo et al. 2009). | ||