maine waters: What we're seeing is this insane level of aggressiveness, said Markus Frederich, a professor at the University of New England, according to National Observer. They're each genetically distinct. Green crabs from Nova Scotia are the same species as their cousins that already inhabit Maine waters, but are ornerier and angrier, threatening to accelerate harm to the coastal ecosystem by gobbling up soft-shell clams and destroying native eel grass, a researcher said. ; The docile green crabs shrink from a threat, while the newcomers are more apt to wave their pincers and charge. The new crab variant that originated in northern Europe is hardier and adapted to colder water than the more docile crab, which originally came from southern Europe. They can destroy eelgrass that provides a hiding place for juvenile sea creatures. Green crabs, even the docile ones, are considered a scourge that can devour soft-shell and juvenile clams. (www.immigrantscanada.com). As reported in the news.