Loggerhead sea turtles

Antibiotic resistance is a growing concern due to the improper use of antibiotics. Not only is antibiotic resistance increasingly occurring in human populations, but it appears to be spreading in wildlife populations too due to drug overuse and misuse in medicine, farming, and industrial settings, and the subsequent release into watersheds. This project examined the prevalence of antibiotic resistant bacteria in the hindgut microbiome of green (Chelonia mydas) (n=60) and loggerhead (Caretta caretta) (n=57) sea turtles. Hindgut swabs were cultured for gram negative bacteria and exposed to 6 antibiotics. 83.3% of samples were resistant or intermediately resistant to at least one antibiotic, and 27.7% of samples were resistant or intermediately resistant to three antibiotics. This study provides more information regarding the relationship between turtle characteristics and the presence of antibiotic resistance in the hindgut of Florida sea turtles, as well as examine the types of bacteria found in the hindgut.

This study examined the environmental and anthropogenic factors that may influence loggerhead sea turtle nest site selection and how these factors vary between successful nesting attempts and false crawls on a high-density sea turtle nesting beach in Boca Raton, Florida. Beach morphology, sand texture, and nests’ proximity to artificial structures were measured using a combination of drone-based photogrammetry, traditional surveys with Real Time Kinematic Global Positioning System (RTK GPS), and sediment granulometry. Proximity to dune crossover stairs was significantly different between nests and false crawls, and the probability of a false crawl occurring decreased as proximity to dune crossover stairs increased. The results of this study will provide researchers with a new tool for nest monitoring and a better understanding of the microhabitat cues that may influence loggerhead sea turtle nest site selection and aid in guiding beach and sea turtle management decisions.

Despite decades of conservation efforts, population recovery remains elusive for the loggerhead sea turtles (Caretta caretta) nesting in Florida, the largest aggregation globally. Limited studies exist regarding reproductive strategies and in-water habitat use of loggerheads in southeastern Florida. I used satellite telemetry to track the movements of 17 nesting loggerheads on Juno and Jupiter Beaches during the 2020 and 2021 nesting seasons. The majority of females displayed high nest-site fidelity. Inter-nesting intervals ranged from 10–19 days and were negatively correlated with water temperatures. Core inter-nesting areas ranged from 3.7–805.8 km2 and were located a mean 1.6 km from land. Mean clutch frequency was 5.9 nests/female, the highest reported for any loggerhead population worldwide. These findings suggest the number of females in the southeastern Florida population may be over-estimated due to an underestimated clutch frequency. Protective measures should target high-use coastal areas to maximize conservation benefits.