Eriocheir sinensis H. Milne Edwards, 1853

The broad, opportunistic diet of the mitten crab suggests that it could be a competitor for food with other detritivorous species, such as freshwater crayfish. The mitten crab could also compete for shelter or space with crayfish and other benthic invertebrate species. Our initial surveys of the crayfishing community and experimental interactions between adult mitten crabs and signal crayfish support such concerns. (Rudnick et al., 2000)

Mitten crabs are likely to effect other Bay species as well. In the North Bay and Delta, mitten crabs are likely to interact with the signal crayfish, in addition to other benthic invertebrates including the Harris mud crab, Rithropanopeus harrissi. The mitten crab has also become established in tributaries of San Pablo Bay (between North San Francisco Bay and the Delta) that provide habitat for the endangered California freshwater shrimp, Syncaris pacifica. The crab's opportunistic foraging habitats could include such shrimp as a prey item. (Rudnick et al., 2000)

Mitten crab burrows were only very dense in tidally influenced areas with steep banks. We observed mitten crab burrow densities ranging from 2/m2 - 18/m2 in 1995/1996, and from 18/m2 to 39/m2 in 1999 (Figure 12). We observed limited areas of bank collapse in areas with high densities of mitten crab burrows. Bank collapse often altered the morphology of the bank, changing the bank from a near vertical wall to a more reduced slope. (Rudnick et al., 2000)

E. sinensis could also reduce populations of native invertebrates through predation and alter the structure of benthic communities (Normant et al. 2002).

The mitten crab is a consumer of autochthonous nutrient sources including benthic macroinvertebrates, and represents new predation pressure particularly in intertidal areas that previously had few large benthic crustaceans. The crab also provides a major new route of nutrient export out of freshwater ecosystems. Given the periodic abundance and widespread distribution of both species throughout this ecosystem, the scale and magnitude of their trophic impacts are likely to be substantial. (RUDNICK & RESH, 2005)