Coast Guard crews are investigating the death of a 77-year-old fisherman off Boothbay Harbor. Crews received a distress call from a fishing boat captain Saturday afternoon, saying a lobster boat was adrift without anyone on board. A helicopter crew located the fisherman floating in the water just after 3 o’clock Saturday afternoon, one mile south of Squirrel Island. Officials say the man was not wearing a life vest of a survival suit. His name has not been released.