Survey of European Green Crabs and Asian Shore Crabs in Salem Sound

Abstract

The European green crab (Carcinus maenas) has been the dominant crab species in New England rocky intertidal zones since the late 1800’s, but since around 2000 they have begun to be outcompeted by a new invasive species, the Asian shore crab (Hemigrapsus sanguineus). Rocky intertidal zones at Chandler Hovey Park in Marblehead, MA and Pavilion Beach in Ipswich, MA were surveyed for both species monthly at low tide from June 2019 through March 2020. Asian shore crabs made up 94% of all crabs surveyed compared to European green crabs (6%). Also, at both sites, the average carapace width of European green crabs was found to be larger than that of the Asian shore crabs collected. From this survey, it appears that Asian shore crabs are outcompeting European green crabs at these locations.