NAHANT – Town and Coast Guard searchers scoured the coastline from Swampscott to the Saugus River Monday morning after a lobsterman found a kayak floating off East Point with a backpack in it.The pack provided no identification information but Town Manager Andrew Bisignani said town officials would like to locate the kayak’s owner.”If anything knows anything, please call Nahant police (781-581-1212). If you lost a kayak, please let us know so we can close this out,” he said.Fire Chief Edward Hyde said the lobsterman found the kayak adrift off Shag Rocks and reported the discovery to public safety officials at 8:55 a.m. Bisignani said the roughly 10-foot-long kayak also contained a signal flare. He did not know whether the flare had been fired.Town authorities launched searchers in the Fire Department ocean rescue boat and harbormaster’s boat. A Coast Guard helicopter based on Cape Cod zoomed low mid-morning across the Nahant coastline while a searcher on a Jet Ski nosed into narrow inlets between rocks along East Point.”We did a thorough search of probable areas. Nahant emergency services responded immediately and efficiently,” Bisignani said.A 45-foot Coast Guard response boat from Scituate joined the search and, by noon, officials expanded the search area to include the entire town coastline as well as offshore water along Revere Beach, Egg Rock and the Saugus River mouth.Officials called off the search at 1 p.m. and Coast Guard spokesman Ross Ruddell said the incident will be filed in Coast Guard records as “a false alarm.”Bisignani said searchers factored currents, wind direction and tides into the search. He said the kayak might have drifted from the Saugus River to Nahant. He did not have an exact cost estimate for town employee overtime and fuel costs associated with the search.”Plus, there is the untold cost of risk to responders, but that is what we are here for,” he said.