Understanding variations in health and immune function across life stages is important for population monitoring and for understanding species’ responses to anthropogenic disturbances. Sea turtles are a model species for evaluating these changes within and across life stages due to their long lifespans with ontogenetic habitat and diet shifts. For my dissertation, I tested whether health-immune proxies differed: across the reproductive season, between species and foraging groups, and with reproductive output for adult female turtles. I tested whether these proxies differed between two habitats, across turtle size, water temperatures, disease severity and species for juvenile turtles, and across three green turtle life stages. Overall, I collected blood samples from turtles captured in the Gulf of Mexico/America, near-shore Florida habitats, and nesting females in Florida between 2020 and 2023. Multivariate statistics, generalized linear mixed models, and hierarchical generalize additive modelswere used to evaluate relationships between collective proxies and predictors within each life stage and across life stages. I found differences across species and foraging aggregations of adult turtles which indicate potential energetic tradeoffs. I also found that smaller juveniles with severe disease states had stronger fluctuations in proxies, especially during colder months. Across life stages, I found proxy differences that align with green turtle ontogenetic habitat and diet shifts and stress-related proxy fluctuations for neritic juveniles. This dissertation highlights the importance of high-quality habitat for all turtle life stages and provides insight into ontogenetic shifts and species comparisons for regional populations. My results suggest conservation priorities should focus on maintaining or improving high-quality habitats and foraging grounds to best support sea turtle populations.
Tiffany Dawson
Dr. Kate Mansfield, Advisor