Invasion
Invasion Description
1st Record: CA/San Francisco Bay (1993, USGS Woods Hole Science Center 2006)
Geographic Extent
CA/Bodega Bay (2003, Bullard et al. 2007; 2011, California Department of Fish and Wildlife 2014); Mason's Marina/CA/Bodega Harbor (2004, de Rivera et al. 2005a); Porto Bodega Marina/CA/Bodega Harbor (2004, de Rivera et al. 2005a); CA/Tomales Bay (2001, Bullard et al. 2007; 2011, California Department of Fish and Wildlife 2014); Drake's Bay Oyster Farm/CA/Drake's Estero (2010, Santa Rosa Press-Democrat 10/15/2012); Clark/CA/Tomales Bay (2004, de Rivera et al. 2005a); Marshall/CA/Tomales Bay (2004, de Rivera et al. 2005a); Miller Park/CA/Tomales Bay (2004, deRivera et al. 2005a); Sacramento Landing/CA/Tomales Bay (2004, deRivera et al. 200a5); Thomas Station/CA/Tomales Bay (2004, de Rivera et al. 2005a); CA/San Francisco Bay (1993, USGS Woods Hole Science Center 2006); Sausalito/CA/San Francisco Bay (2000); Hunters Point/CA/San Francisco Bay (Ruiz et al., unpublished data); Port of San Francisco/CA/San Francisco Bay (Ruiz et al., unpublished data); Richmond Marina, Richmond/CA/San Francisco Bay(Ruiz et al., unpublished data; 2010, Marrafini et al. 2017); Treasure Island/CA/San Francisco Bay (Ruiz et al., unpublished data); San Francisco Marina, Richmond/CA/San Francisco Ba y(Ruiz et al., unpublished data; 2010, Marrafini et al. 2017); San Leandro Marina, Richmond/CA/San Francisco Ba y(Ruiz et al., unpublished data; 2010, Marrafini et al. 2017); Treasure Island/CA/San Francisco Bay (Ruiz et al., unpublished data); Pier 39, San Francisco/CA/San Francisco Bay (2004, Cohen et al. 2005)a; Presidio Yacht Club, San Francisco/CA/Golden Gate (2004, Cohen et al. 2005)a; San Mateo Bridge Pylon/CA/South San Fracisco Bay (Cohen et al. 2005b); CA/Halfmoon Bay (1997, Bullard et al. 2007); CA/Elkhorn Slough (1998, USGS Woods Hole Science Center; Bullard et al. 2007); Moss Landing/CA/Elkhorn Slough (2003, de Rivera et al. 2005a; 2011, California Department of Fish and Wildlife 2014); CA/Morro Bay (2000, Bullard et al. 2007; Needles 2007; 2011, California Department of Fish and Wildlife 2014); Port San Luis/CA/Pacific Ocean (2002, Bullard et al. 2007)
Vectors
| Level | Vector |
|---|---|
| Alternate | Hull Fouling |
| Alternate | Fisheries Accidental (not Oyster) |
| Alternate | Oyster Accidental |
Regional Impacts
| Ecological Impact | Competition | |
| Didemnum vexillum was one of several invasive fouling species which showed increased growth (% coverage) at temperatures 3.5 and 4.5⁰C above the ambient temperature in Bodega Harbor (13.5⁰C), while the native Distaplia occidentalis showed reduced survival (Sorte et al. 2010). Didemnum vexillum was one of a group of seven non-native species, most of which were rare or absent in 1970-1971, but were among the eight most abundant species in 2005-2009. Spawning periods and abundance of species in this group appeared to be favored by a 1⁰C increase in average temperatures at this site over a 30-year period (Sorte and Stachowicz 2011). Didemnum vexillum overgrowth had a modest effect on the growth of eelgrass (Zostera marina) blades in mesocosms filled with water from Tomales Bay (Long and Grosholz 2015). | ||
| Ecological Impact | Habitat Change | |
| Didemnum vexillum faciltated growth of invertebrates (polychaetes and tanaids) on eelgrass blades (Long and Grosholz 2015) | ||