Invasion
Invasion Description
1st record: Eureka/CA/Humboldt Bay (1995, Miller 1996, Introduced, Established). Recruitment in the Oregon-Washington part of the range has been sporadic, depending on favorable currents and warmer water temperatures in 2003, 2005, 2006 and 2010, influenced by the Pacific Decadal Oscillation, and the El Niño Southern Oscillation (Yamada et al. 2015).
Geographic Extent
Eureka/CA/Humboldt Bay (1995, Miller 1996, introduced, established); Coquille/OR/Coquille Bay (1997, Cohen and Carlton 2003); OR/Coos Bay (1997, introduced, established); Waldport/OR/Alsea Bay (1998, Carlton and Cohen 2003); Newport/OR/Yaquina Bay (1998, introduced, established, Washington Department of Fish and Wildlife 1997-1999); Siletz/OR/Siletz Bay (1998, Carlton and Cohen 2003); OR/Salmon River Estuary (1998, Carlton and Cohen 2003); OR/Netarts Bay (1998, Carlton and Cohen 2003); OR/Tillamook Bay (1998, Carlton and Cohen 2003); WA/Willapa Bay (1998, Carlton and Cohen 2003; Yamada et al. 2005); WA/Grays Harbor (1998, Carlton and Cohen 2003; Yamada et al. 2005); East of Tongue Point/Colombia River/OR (04/22/2025, Oregon Dept. of Fish and Wildlife)
Vectors
| Level | Vector |
|---|---|
| Alternate | Natural Dispersal |
| Alternate | Ballast Water |
| Alternate | Hull Fouling |
Regional Impacts
| Ecological Impact | Predation | |
| Carcinus maenas fed at lower rates overall than native Metacarcinus magister (Dungeness Crab), collected from the Oregon coast (no location specified), when feeding on native mussels (Mytilus trossulus), but were more efficient than equal-sized M. magister at feeding on native Olympia Oysters, Ostrea lurida, because of greater claw strength (Yamada et al. 2010). Palacios and Ferraro (2003) found that Carcinus maenas preferred O. lurida to 3 other species of bivalves (introduced Venerupis philippinarum (Japanese Littleneck) and native Macoma nasuta (Bent-nose Macoma) and Cryptomya californica (California Softshell), when offered in equal amounts. | ||