Invasion
Invasion Description
1st record: OR/Coos Bay (1875, Dall 1897, cited by Carlton 1979)
Geographic Extent
WA/Grays Harbor (1888, Collins 1892, cited by Palacios et al. 2000; 1905, Keep 1905, cited by Carlton 1979); near Hokiam/WA/Grass Creek, Grays Harbor (1999, Wilson amd Partidge 2007); Moon Island & Grass Creek/WA/Grays Harbor (surviving populations, 1984, Palacios et al. 2000, Shell deposits indicate a much more extensive population which had a mass mortality in 1895-1997); WA/Beardslee Slough (1999, Wilson amd Partidge 2007); WA/Willapa Bay (1884, Stearns 1885, cited by Carlton 1979); Omeara Point/WA/Willapa Bay (2000, Cohen et al. 2002); Naselle River Bridge/WA/Willapa Bay (2000, Cohen et al. 2002); WA/Upper Palix River, Willapa Bay (2000, Cohen et al. 2002); Palix River Bridge/WA/Willapa Bay (2000, Cohen et al. 2002); WA/Stackpole Slough, Willapa Bay (2000, Cohen et al. 2002); WA-OR/Columbia River (Gaumer et al. 1974, cited by Carlton 1979); Ilwaco/WA/Baker Bay, Columbia River (2002, Sytsma et al. 2003); OR/Trestle Bay, Columbia River (2002, Sytsma et al. 2003); OR/Nehalem River (Marriage 1954, cited by Carlton 1979); OR/Tillamook Bay (1917, Edmondson 1922, cited by Carlton 1979; 1977, Carlton 1979); OR/Netarts Bay (Marriage 1954, cited by Carlton 1979); OR/Nestuca Bay (1917, Edmondson 1922, cited by Carlton 1979); OR/Salmon River (Marriage 1954, cited by Carlton 1979); OR/Siletz Bay (1917, Edmondson 1922, cited by Carlton 1979); Newport/OR/Yaquina Bay (1917, Edmondson 1920, cited by Carlton 1979); Waldport/OR/Alsea Bay (1943, Marriage 1953, cited by Carlton 1979); Florence/OR/Siuslaw River (1920, 'Introduced about 40 years ago' (1880?), Edmondson 1920, cited by Carlton 1979); Reedsport/OR/Umpqua River (1943, Marriage 1953, cited by Carlton 1979; 1977, Carlton 1979); OR/Coos Bay (1875, Dall 1897, cited by Carlton 1979; 'common to abundant throughout the bay', Carlton 1989); OR/Coquille River (1943, Marriage 1953, cited by Carlton 1979); CA/Smith River Delta (1977, Carlton 1979); Crescent City/CA/Lake Earl (Weymouth 1920, cited by Carlton 1979); CA/Stone Lagoon (Weymouth 1920, cited by Carlton 1979); CA/Big Lagoon (Weymouth 1920, cited by Carlton 1979); CA/Southport Landing, Mad River Slough, Samoa Channel, Humboldt Bay (Boyd et al. 2002; 1917, California department of Fish and Game 1917, cited by Carlton 1979); CA/Eel River (Weymouth 1920, cited by Carlton 1979)
Vectors
| Level | Vector |
|---|---|
| Alternate | Oyster Accidental |
| Alternate | Fisheries Intentional |
Regional Impacts
| Economic Impact | Fisheries | |
| In Humboldt Bay. 'It is taken for bait and food by sport clammers.' (Boyd et al. 2002). Recreational clamming for M. arenaria is also popular in Oregon. According to the Oregon Division of Fish and Wildlife, this clam is present in nearly every Oregon estuary (http://www.dfw.state.or.us/mrp/shellfish/bayclams/dig_softshell.asp). In Washington, they are less popular than Butter Clams (Saxidomus gigantea) or Littlenecks (Leukoma staminea- Pacific Littleneck; Venerupis philippinarum- Japanese Littleneck) (Washington Department of Fish and Wildlife 2012, http://wdfw.wa.gov/fishing/shellfish/clams/eastern_softshell.html). | ||
| Ecological Impact | Habitat Change | |
| In Grays Harbor WA, large shell deposits provide a highly favorable habitat for settling Dungeness Crab (Metacarcinus magister) juveniles. High densities of these crabs may, in turn, limit the recruitment of M. arenaria). | ||