One of the biggest threats to the San Francisco Bay's estuarine community is a tiny crab with furry claws. The Chinese mitten crab may sound benign, but its voracious appetite and escalating population is compromising the ecology of this once-thriving system. Invasive Aquatic and Wetland Animals explains how invasive aquatic and wetland animals are introduced, how they affect aquatic systems, and what is being done to contain them.