I had the pleasure of going to Sapelo Island in September 2004. It is off the coast of Georgia, about 30 miles from Savannah. It is one of the few islands that are untouched by the trappings of tourism and gentrification. There is some kind of decree or something that declares the island not be gentrified and kept as a landmark. I went for a writing workshop and one of our workshop leaders was Cornelia Walker Bailey, a native Geechee who wrote
God, Dr. Buzzard, and the Bolito Man : A Saltwater Geechee Talks About Life on Sapelo Island, Georgia.
http://www.amazon.com/gp/product/0385493770/qid=1139984467/sr=1-1/ref=sr_1_1/103-1453902-3147020?s=books&v=glance&n=283155

Cornelia is a walking encylopedia on the Geechee culture and the island. She said they are called Geechee on the islands off the coast of Georgia and called Gullah on the islands off the coast of S.C. The children ride the ferry to go to school on the mainland. The population is dwindling as you say as more young people move to the mainland for jobs and go away to school. The island is beautiful and full of history.