About This Project

Caretta caretta (loggerhead sea turtle) is a globally threatened species. The Georgia DNR relocates some nests for conservation management, yet we don't fully understand how a multitude of environmental factors may affect success of nests which is critical for successful sea turtle conservation and management. I will evaluate how temperature, moisture, vegetation, flooding, elevation, and dune orientation affect success of loggerhead nests on Ossabaw Island, Ga.

Ask the Scientists

What is the context of this research?

While working on St. Catherines Island, Ga, which relocates almost 60% of loggerhead nests, I noticed that some nests relocated to high dunes (apparent prime locations for incubation) had low hatch success while other nests located 5-10m away had hatch successes in the 80-100% range. After endless sweaty hours of relocating eggs to 'better' locations, to see these nests completely fail during incubation was disheartening. I hypothesized that temperature and moisture--the two factors credited with success in nest incubation--can't be the only things controlling success on these beaches. The current 'higher-nest-higher-success' thought behind management now may become outdated as temperatures increase, and other factors may be more important in determining hatch success.

What is the significance of this project?

This project will help us better understand how temperature, moisture, vegetation, tidal flooding, elevation, and dune morphology interact to impact hatch success (proportion of hatched to unhatched eggs in each nest). Management protocols call for the relocation of nests which are at risk of tidal flooding. While current relocation protocol moves nests to the highest nearby dunes, some studies suggest that with climate change, these nests at high elevations may be getting too hot. Because so many nests are relocated, it is important to move them to locations which have the best chance of success. By improving our knowledge about other environmental factors which could impact nest success, we can update management practices to lead to more successful relocated nests.

What are the goals of the project?

We hope to better incorporate multiple environmental factors that impact hatch success into predictive models using an AIC modeling method to determine which combination of factors is most important in determining hatch success. These models can be used to predict hatch success in environments where nest placement will experience a variety of these factors (eg. nests placed in high elevation, high vegetation, and high temperatures; low elevation, no vegetation, intermediate temperatures). I will work with the Georgia DNR to update loggerhead management for the state of Georgia. Hopefully this will result in better allocation of resources and increase overall success of nests.