The arrival of the Chinese mitten crab to the San Francisco Bay-San Joaquin Delta (Bay- Delta) ecosystem has been a source of widespread concern. This crab has spread from its native range, in China, to coastal ecosystems throughout Europe and, most recently, into North America. The Chinese mitten crab population in California has exploded within the last decade to cover hundreds of miles of the Bay-Delta and its tributaries. The Chinese mitten crab is a large, catadromous crab, moving from freshwater habitats where it spends its juvenile years to saltwater habitats in order to reproduce. In other countries into which this species has been introduced, the abundance and behavior of the crab has caused detrimental impacts to fisheries and loss of bank stability in areas where it burrows.

Through a grant from the Water Resources Center, we set out to examine the ecology, distribution, and economic and ecological impacts of the Chinese mitten crab in the fresh and saline waters of San Francisco’s South Bay. The Chinese mitten crab offers excellent opportunities to: 1) study the population dynamics of an invasive species; 2) examine differences and similarities for this organism between its native and new environments; and 3) use research findings to make recommendations for understanding and control of this organism.