They’re shoring up a way of life. America’s most northerly East Coast state has 15 offshore islands, like Vinalhaven, that are inhabited year-round. It’s gotten harder over the years to keep communities thriving in an environment whose industries, like granite cutting, have faded, and island kids often want to escape the isolation. Today’s population is half of what it once was. But affordable housing projects, focused development efforts, and community support for lifelines like ferries and schools are stabilizing life there, helping ensure that Maine’s islands can stay afloat.