Young notes that the first appearance of the relatively new invasive species was in 1988, but it is now found up and down the East Coast.
“The larvae spend about a month drifting in the water so (they) can be transported considerable distances along the coast pretty quickly,” he wrote in an email. The crabs were found locally in Salem and Marblehead in 2000.
Unlike the invasive European green crab, the Asian shore crab prefers rocky cobble beaches but can be found in soft sands, as well.
“It is very successful as an invasive species, at least partly because its reproductive rate is very high,” Young said. “A single female can produce 50,000 eggs three to four times during the summer, whereas native crabs reproduce only twice each season.”
Asian shore crabs also feed on juvenile clams and other invertebrates, but pose less of a threat than the European green crab because the shore crab generally hunts in places where clams are absent anyway, Young wrote.