Invaders to our coastline come in all forms—plants, animals, parasites—but they all have one thing in common: By their very presence, they alter the balance of ecosystems that produce some of our most sought-after commercial and recreational species of fish and underwater food. Although estimates vary as to the economic impact of these unwelcome newcomers, some put the cost to businesses as high as $100 billion a year.

The mitten crab—which like any good villain has an a.k.a., in this case either the big binding crab and the Shangahi hairy crab—is at the top of the list of invasive species that are an almost constant threat to what we have come to think of as the natural population of our waters.