Green Crab Invasion

The green crab invasion is the worldwide spread of the European green crab Carcinus maenas, native to the northeast Atlantic and Baltic and one of the IUCN 100 of the World’s Worst Invasive Alien Species. It has established on the North American Atlantic and Pacific coasts, in Australia, South Africa, Japan, and South America, carried in ballast water, hull fouling, and shellfish movements. The crab reaches about 90 mm carapace width, tolerates a wide salinity and temperature range, and preys on clams, mussels, and juvenile bivalves, degrading eelgrass and damaging soft-shell clam and other shellfisheries. Most programs now aim at population control rather than eradication.