P3.6 Friday, Jan. 6 Predicting impacts of global climate change on the Northwest Atlantic Loggerhead sea turtle (Caretta caretta) population: Locomotor responses of hatchlings to differing incubation temperatures FISHER, L.*; OWENS, D.; GODFREY, M.; College of Charleston; College of Charleston; North Carolina Division of Environment and Natural Resources email@example.com
Sea turtles have a temperature-based sex determination system. For the Atlantic loggerhead sea turtle (Caretta caretta), a major concern of rapid climate change is that increasing sand temperatures on nesting beaches are female-skewing the hatchling sex ratio. Apparent population-wide female-biased hatchling sex ratios contrast with observations of juvenile populations, where sex ratios have remained constantly female-biased at about 2 to 1 over the past 30 years. It has been suggested that some unknown factor is affecting loggerhead survival resulting in an unexplained differential loss of ~60% of female hatchlings per year. The principle theory to explain this hatchling mortality is that incubation temperature affects traits that influence survival. Previous studies on hatchling performance have not tested the upper or lower limits of incubation temperature, and fitness consequences remain untested or unconfirmed. In this study, laboratory experiments will be conducted to test for an effect of incubation temperature on performance of loggerhead hatchlings. The initial hatchling dispersal period will be simulated in a controlled laboratory setting, and performance and locomotor variables will be tested over a 24-hour period. Differences in performance that may be seen from hatchlings incubated at high temperatures are important in light of increased sand temperatures, and could indicate increased mortality from incubation temperature effects. Preliminary performance data will be presented. By conducting controlled laboratory experiments on hatchlings, the results will support or refute incubation temperature as a significant variable affecting loggerhead hatchling survival.