Smaller Size of Nesting Loggerhead Sea Turtles in Northwest Florida

Area of Science:

• Marine Biology
• Conservation Science
• Ecology

Background:

• Sea turtle populations face recovery challenges, with body size distribution affecting estimates.
• Recent observations indicate a decrease in nesting sea turtle size, raising concerns about reproductive capacity.

Purpose of the Study:

• To examine the relationship between loggerhead turtle size and hatchling production.
• To assess the implications of reduced body size on loggerhead turtle fecundity and population dynamics.

Main Methods:

• Analyzed a seven-year dataset of loggerhead turtle nesting on St. George Island, Florida.
• Collected morphometric data (CCLmin) and GPS locations during nighttime surveys.
• Monitored nest disturbances and hatchling production from morning surveys.

Main Results:

• Mean minimum curved carapace length (CCLmin) was 94.3 cm; 9.1% of turtles were below the 87 cm minimum size at maturity threshold.
• Clutch size increased by one egg per 1 cm increase in CCLmin, while wash-out rates rose by 0.52%.
• Larger turtles produced larger clutches, but these nests experienced increased wave wash-out, potentially limiting net hatchling output.

Conclusions:

• Body size significantly influences loggerhead turtle fecundity and nest success.
• Size-mediated factors are crucial for accurate demographic modeling and effective conservation strategies for endangered sea turtles.
• Management decisions should consider the complex relationship between turtle size, clutch size, and nest survival rates.