Smaller Size of Nesting Loggerhead Sea Turtles in Northwest Florida

The distribution of individual body sizes within a population can have substantial impacts on recovery estimates for endangered species. Recent studies have observed a reduction in the size of nesting sea turtles with potential implications for fecundity. To investigate the size of reproductive individuals and subsequent impacts on hatchling production for loggerhead turtles in northwest Florida, we evaluated a seven-year dataset from St. George Island, Florida, USA-the dominant nesting site in this region. Morphometric measurements and GPS locations were collected during nighttime surveys, whereas nest disturbances and hatchling production were reported from morning surveys. Mean minimum curved carapace length (CCL_min) was 94.3 cm ± 5.7 cm SD (range: 80.2-109.1 cm). Out of 232 individuals, 9.1% fell below the 87 cm CCL_min threshold currently adopted by U.S. agencies as the minimum size at maturity. For each 1 cm increase in CCL_min, an increase by 1 egg was observed in clutch size, and wash-out rates increased by 0.52%. Though the largest turtles laid the largest clutches, these nests also had a greater probability of wave wash-out, potentially moderating overall hatchling production from these individuals. These results highlight size-mediated factors related to fecundity-important elements for demographic modeling and management decisions.