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The History and Effects of Exotic Species in San Francisco Bay
San Francisco Bay Project, Water Resources Division
J. Thompson, F. Parchaso, A. Alpine, J. Cloern, B. Cole, O. Mace, J. Edmunds, J. Baylosis, S. Luoma, F. Nichols
What are the exotic species doing now?
Plus, the unexpected effects of exotic species introduction.

Click on any photo to see larger images.
Chinese Mitten CrabThe Chinese Mitten Crab may have been illegally introduced in 1992-94 as a food resource. It burrows into and weakens dikes and levees. It is also a host to the oriental lung fluke, a human parasite. It is also a host to the oriental lung fluke, a human parasite.
Atlantic Green CrabThe Atlantic Green Crab, first seen in the bay 1989-90, preys on juvenile Dungeness Crab which use the bay as a nursery ground.
Unexpected effects ...
Unexpected effects of exotic speciesAny introduced species may create a new pathway for contaminants into the higher trophic levels. New species may accumulate contaminants more efficiently and be more productive than native species and thus may increase the contaminants passed up the food web.
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CordgrassSmooth cordgrass was first planted in the bay to mitigate a destroyed marsh in the 1970's. It replaces the native species and advances onto and reduces the mudflat area.

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Page Last Modified: Thursday, 13-Dec-2007 12:21:11 PST