MARBLEHEAD – Selectmen are making their final attempt to prevent Massachusetts Bay Transportation Authority cutbacks that could eliminate Boston-bound bus routes from Marblehead and other North Shore communities.John Heffernan, who represents Marblehead on the MBTA Advisory Board, told selectmen Wednesday evening that the MBTA has completed an extended series of public hearings on service cutbacks and fare increases to resolve a $159 million operating deficit.?The advisory board has come up with a plan with no service reductions,” he said, urging the board to support it.Selectmen voted unanimously to send letters supporting the advisory board proposal and opposing service reductions to Gov. Deval Patrick, state Sen. Thomas McGee, D-Lynn, state Rep. Lori Ehrlich, D-Marblehead and the MBTA Board of Directors, on a motion by Selectman Judy Jacobi.Jacobi attended a public hearing in Lynn to oppose the service cutbacks, on the grounds that MBTA buses carry seniors to medical appointments and other services.?The MBTA and the state need to have more of a long-term plan,” Heffernan said. He pointed out that no study had been made of usage of the Boston-bound bus lines that serve Marblehead and added “People are using them.”?I?m convinced that they really did hear what this board said,” Jacobi said.Heffernan said one creative solution that has been suggested is an additional 50-cent fare on the days of major sporting events, when MBTA usage increases substantially.Selectman Bret Murray recalled that the MBTA faced a similar deficit several years ago. “They can?t keep up with their own costs, let alone long-term increases,” he said.