Until recently, the story of Maine’s offshore islands has been a dismal tale of declining year-round population. A century ago, there were more than 300 full-time island communities, most of them with general stores and schools and many with their own post offices. That number dropped to 14, as the communities died out and islands became summer resorts.

Now, change is in the air. The total year-round island population grew by 7 percent in the last decade, according to an analysis by the Rockland-based Island Institute. And the number of year-round island communities has risen to 15.

Much of the growth came on Vinalhaven, Maine’s most populous island. It went from 1,072 full-time residents in the 1990 census to 1,235 in the 2000 census. The fifteenth full-time settlement, says the institute, is Great Diamond and Little Diamond in Casco Bay, which were practically deserted in winter for many years. Great Diamond now has new townhouses, a health club and a restaurant catering to new residents including retirees and some who work in Portland, a 20-minute ferry ride away.

According to census figures, the Cranberry Isles, off Mount Desert Island, have slipped from 189 year-rounders in 1990 to 128 in 2000. Town Clerk Frances Bartlett, who keeps her own running census, puts the present year-round population at 138 – 53 on Great Cranberry and 85 on Little Cranberry, also known as Islesford. Her higher figure includes several island families who spend winters on the mainland while they have children in high school.

Both islands have stores and post offices. The school on Great Cranberry has suspended operations, but the Islesford school still is going strong, with 12 students, including one who goes over from Great Cranberry. The non-profit Cranberry Isles Realty Trust is helping maintain island population by providing affordable housing for qualified year-round residents.

To round out the Cranberry Isles picture, Ms. Bartlett puts the number of summer residents at 198 for Great Cranberry, 242 for Islesford, and another 90 for the three other islands in the group, Baker, Bear and Sutton, which are deserted in the winter.