2. Asian shore crab (East Coast states from Maine through North Carolina)
Asian or Japanese shore crab is native to to parts of Russia and Japan, but has become invasive along the East Coast, from Maine through North Carolina. It was probably introduced into the United States by international ship travel. Asian shore crabs are small, usually measuring not more than an inch and a half across, but are opportunistic feeders and will consume small fish, crustaceans, algae and anything else they come across. Its primary negative impact as an invasive species is displacement of native crab populations, as it competes for similar habitat to native blue crab, rock crab, and lobster.