|Transoceanic transport mechanisms: the introduction of the Chinese mitten crab Eriocheir sinensis to California|
|Cohen, A.N.; Carlton, J.T. (1997). Transoceanic transport mechanisms: the introduction of the Chinese mitten crab Eriocheir sinensis to California. Pac. Sci. 51(1): 1-11|
|In: Pacific Science: Honolulu. ISSN 0030-8870, more|
Introduced species; Eriocheir sinensis H. Milne Edwards, 1853 [WoRMS]; INE, USA, California, San Francisco Bay [gazetteer]; Marine; Brackish water
Live importation of the Chinese mitten crab, (Eriocheir sinensis H. Milne-Edwards, 1854) was banned by both California and the United States in the late 1980s because of concerns about potential damage to levees, rice crops, and natural ecosystems, and because it harbors a human parasite. Nevertheless, mitten crabs were present in San Francisco Bay by 1992 and well established by 1994, providing the most recent example in a late-twentieth-century pulse of human-mediated transoceanic and interoceanic crab dispersals. Of 10 mechanisms available for the long-distance transport of crabs, evidence from the history of the mitten crab's global spread, data on ship traffic, the sampling of ballast water fauna, and recent patterns of introductions support the hypothesis of introduction via ballast water. Alternatively, the pattern of governmental interception of mitten crabs, their high market value, and continuing pressure to lift the import ban suggest that introduction may have been achieved via an intentional, private-party inoculation to establish a food resource. For either mechanism, the immediate source is more likely Asia than Europe. Amid a global burgeoning of potential transport mechanisms for estuarine and neritic organisms, knowledge of which mechanisms are in fact acting is essential for directing efforts to moderate the pace of such introductions.