My Research Program is Based at the Georgia Sea Turtle Center / Jekyll Island Authority.
Monitoring of Nesting Loggerhead Sea Turtles on Jekyll Island, Georgia
Loggerhead Sea Turtles (Caretta caretta) are a federally-threatened species that nest along North America’s Atlantic Coast from Florida to Virginia. Approximately 50 females nest each year on Jekyll Island, Georgia depositing a total of over 100 nests (each female will deposit several nests within a nesting season). We are continuing a long-term monitoring effort in collaboration with the Georgia Department of Natural Resources to track overall trends for the species in the region. During the nesting season (May-July) we patrol the beach every night to identify individual turtles while also locating and protecting their nests. This monitoring program lends itself to several research projects.
- Genetics of Loggerhead Sea Turtles Nesting in Georgia. The data and biological samples we collect on Jekyll Island contribute to a large-scale effort led by Drs. Brian Shamblin and Joseph Nairn (University of Georgia) that uses genetics to identify mother turtles associated with each nest, allowing us to learn more about population trends and behavior of individual animals.
- Characterizing Loggerhead Sea Turtle Behavior Following False Crawls. Loggerhead Sea Turtles often crawl on shore but leave without nesting, a behavior known as a false crawl. We know little about this behavior although it often (but not exclusively) occurs in response to anthropogenic disturbance. Through a combination of physical tagging efforts and genetic data, we are working to determine where and when Loggerhead Sea Turtles eventually nest following false crawls; this information will help us learn more about the biology of these animals while identifying how false crawls should be interpreted in the context of management plans.
- Injury Rates Among Loggerhead Sea Turtles in Georgia Waters. Boat strikes, interactions with fishing gear, and predators all have the potential to influence federally-threatened Loggerhead Sea Turtles, by characterizing injuries observed among nesting females as well as those captured at sea, we are assessing the prevalence of injuries among individual animals and hope to use these data to make inferences about the population.
- Endocrine Disrupting Chemicals in Nesting Loggerhead Sea Turtles and Assessing Transfer to Offspring. Contaminants in the environment have the potential to accumulate in marine reptiles and lead to negative effects. For example, endocrine disrupting chemicals may be carcinogenic and affect sexual development. In collaboration with investigators at Loggerhead MarineLife Center and UGA, we are taking blood samples from nesting Loggerhead Sea Turtles, quantifying concentrations of endocrine disruptors, and identifying whether females pass these chemicals off to their developing offspring.
Diet and Plastic Ingestion of Sea Turtles in the Southeastern United States
It can be difficult to generate even basic natural history information for large and wide-ranging marine reptiles like sea turtles. At the same time, there is increasing interest in whether these animals are susceptible to plastic ingestion. We are taking advantage of sea turtles admitted into the GSTC hospital by collecting fecal samples and storing them for analysis. This information will help us understand both the natural diet of sea turtles as well as whether they are susceptible to ingesting plastics in the region.
Interactions Between Recreational Anglers and Sea Turtles
Although considerable attention has been dedicated to issues surrounding sea turtles and commercial fishing operations, less is known regarding how recreational fishing is impacting these animals, particularly near shore. Juvenile Kemp’s Ridley Sea Turtles forage in the region and each year many are accidentally hooked by anglers on fishing piers. In collaboration with multiple partners, we are generating new information that will help us learn more about how and why this conflict occurs in the hopes of offering recommendations that will reduce impacts to this critically-endangered species.
Spatial Ecology of Box Turtles on a Barrier Island Managed for People and Wildlife
The four golf courses on Jekyll Island, Georgia are each Certified Audubon Cooperative Sanctuaries. We are using radio-telemetry to track Box Turtles that use these golf courses and are characterizing their movements and habitat preferences. It is our hope that this information will allow us to continue to use the landscape in ways that are compatible for both people and reptiles.
Long-term Monitoring of a Barrier Island Freshwater Turtle Assemblage
Jekyll Island is home to over a dozen species of freshwater turtles and we are continuing a long-term effort to mark and identify these animals. Over time these observations help us understand the size of their populations as well as how the different species are distributed across the island. We are also learning a lot about their biology and conservation; for example by x-raying the turtles we capture we can determine how many eggs they lay and if they have ingested any foreign objects like fish hooks.
Maintaining Vitamin D Levels for Sea Turtles Undergoing Rehabilitation
Wildlife rehabilitation facilities are tasked with improving the health of sick and injured marine turtles but their size and physiology present unique challenges. One of the most significant challenges for indoor facilities is maintaining appropriate Vitamin D3 levels, essential for a wide range of bodily functions including skeletal growth, reproduction, and development. In collaboration with Zoo Med, we are evaluating novel lighting systems and hope to generate recommendations for the captive care of sea turtles undergoing rehabilitation.
Survival and Development of Loggerhead Sea Turtle Eggs in a Changing World
Climate change is predicted to influence the temperature and humidity of sea turtle nests, with unknown consequences for these animals. In collaboration with Dr. Adam Rosenblatt (University of North Florida), we are developing an experimental framework to evaluate how environmental conditions influence both the survival and sex ratio of Loggerhead Sea Turtle hatchlings.
Survival and Movements of Freshwater Turtles Following Rehabilitation
Freshwater turtles are admitted to wildlife rehabilitation centers throughout North America following interactions with dogs, fish hooks, and cars, among other threats. Although considerable resources are used to treat these turtles and get them healthy enough to be released back to the wild, we have little information to evaluate the long-term effects of the injuries and subsequent rehabilitation. We are using radio-telemetry to monitor a variety of freshwater turtles released on Jekyll Island to assess their survival and behavior.