WELLFLEET -- An acoustic receiver, attached to a buoy, that uses email to alert officials and lifeguards to the presence of a tagged white shark is in place in the waters off Wellfleet’s Newcomb Hollow Beach and will soon be installed off Nauset Beach in Orleans and Head of the Meadow in Truro, according to shark researcher and scientist Greg Skomal, of the state Division of Marine Fisheries. The device can detect a tagged shark if it swims within 100 to 200 meters of the buoy, he said, but issues no alert when non-tagged sharks, population unknown, swim by, meaning...