Green crabs may devour America's entire seafood buffet. In New England, the crabs (Carcinus maenas) started by pinching scallop and mussel populations. Now the crabs chomp on clams. Fisheries managers fear that the crabs will move onto the king of American seafood, the Maine lobster (Homarus americanus).
"[The crabs'] food preference has systematically moved through all of shellfish resources on a sequence based on convenience," Chad Coffin, president of Maine Clammers Association, told the Bangor Daily News. "When the clams are gone, what are they going to eat? People may think lobsters are big and tough, but they're not."
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On the other side of the continent, invading hordes of green crabs devour oysters and other crab species, including the delicious Dungeness, in the waters off Oregon and Washington.
Green crabs lack the claw strength to crack into full-grown oysters and other marine mollusks. Instead, the crabs dig young oysters and clams out of up to six inches of sand. The invaders can consume 40 half-inch clams per day, according to the Washington Department of Fish and Wildlife.