Brian Beal, a University of Maine at Machias biologist, has been studying the decline of clam populations in the state and said warm weather, coupled with an extremely successful predator, historically spells disaster for clams. Green crabs, originally from Japan, were first recorded on Long Island, N.Y., in the mid-1860s and weren’t seen in Casco Bay until the early 1900s, Beal said. The green crab populations have been kept in check by severe cold snaps, Beal said, experienced frequently throughout the last century, allowing clams and other shellfish to recover.
