The Concerned Citizens of Montauk will hold its annual meeting at the Montauk Firehouse on Saturday at 3 p.m. After a brief meeting, “Beaches or Boulders: Montauk’s Future Shoreline” will be discussed by guest speakers including Orrin H. Pilkey, a James B. Duke professor emeritus of earth and ocean sciences at Duke University. A pre-eminent marine and coastal geologist, Mr. Pilkey specializes in the study of ocean beaches and coastal policy, particularly in resort communities.