This article is about the green crab from Europe that has threatened many native species in the US. Although the green crab is an invasive species, the species that are now in Cape Cod have indirectly prevented erosion by driving down the population of a native crab species that has multiplied out of control. The native crab species is the purple marsh crab. Due to over fishing, the crabs predators have depleted which caused the puple marsh crab population to soar. Since the the population soar, they have eaten massive amounts of marsh grasses which hold the marsh soil together, preventing erosion. Although green crabs do not regularly live in marshes, the invasive green crabs have begun to colonize in the marshes. Researchers showed that green crabs evict purple marsh crabs from burrows, either killing them or scaring them away. Both these species have helped prevent erosion by eating the grasses. Although invasive species are normally regarded to ruin populations, these crabs have been seen to help improve the marshlands.
Ecology and The Living World: Invasive Species