University of Georgia scientist: genetics show Kiawah’s turtles are linked across the South Atlantic and Kiawah should host male-index work

Members of the town council and volunteers gathered for the inauguration of "Kiawah Conversations" to hear Dr. Brian Chamblin, an associate research scientist at the Warnell School of Forestry and Natural Resources, University of Georgia, present new findings about loggerhead and green turtle genetics.

Kaye, a town council member and chair of the environmental and resiliency committees, opened the program by saying residents were "deeply concerned about the health of our turtles, our dolphins, our shorebirds, our bobcats" and that the new series aims to increase public understanding and involvement.

Dr. Chamblin described a long-running genetic tagging effort that uses microsatellite markers to build unique genetic fingerprints for nesting females. "We have assigned 129,000 nests to almost 15,000 unique females in this population," he said, explaining that eggshell or small eggshell/tissue samples let researchers match nests to individual mothers without needing to handle adult turtles.

That genetic database has allowed researchers to sharpen population estimates and detect relatedness among females, Chamblin said. For the Northern Recovery Unit (north of Florida), the project has recorded roughly 15,000 distinct females; for Kiawah Island specifically, he reported nearly 5,000 nests and approximately 1,000 different mothers on record since the local sampling began in about 2010.

Chamblin outlined a newer technique to detect breeding males by extracting and genotyping sperm DNA trapped in the yolk membrane of eggs. He described pilot and validation work in Florida and at other study sites and reported pilot-sample results: "From 565 hatchlings from 324 nests we assigned 245 mothers and 241 fathers," which suggests male contributions in that sample were closer to a 1:1 ratio than earlier estimates derived from different sampling methods.

The presenter cautioned that methods and sample windows matter, and that many uncertainties remain. He also discussed how climate-driven warming affects hatchling sex ratios—hotter nests produce more females—and warned that management actions such as moving clutches can have complex consequences for hatchling size, sex ratio and survival.

Arguing for strengthened local participation in the male-detection work, Chamblin asked the audience to consider making Kiawah an index site to build a male database and to map where mating is occurring offshore. He also thanked the conservancy and local fundraisers: "We don't have federal funding anymore to do any of this work," he said, noting current efforts rely on donations and volunteer sample collection.

Audience members asked questions about species differences in hatchling behavior, long-term nesting observations and whether males are mediating genetic mixing across the region. Chamblin said males likely move and breed at large scales and that the mixture seen in nuclear DNA supports male-mediated connectivity between Florida and more northern nesting sites.

The town council and volunteers closed by recognizing turtle-patrol members and encouraging continued participation in monitoring and sample collection, which Chamblin described as essential to scaling the genetics work.

Next steps: Chamblin asked local organizers and volunteers to consider supporting an index-site effort for Kiawah, and he provided a QR code to his lab website for further information and volunteer coordination.