Meeting Abstract

P2.67  Tuesday, Jan. 5  Evaluating the sex ratios of juvenile loggerhead sea turtles inhabiting the Atlantic coastal waters of Florida LAYTON, Jenny Estes; WIBBELS, Thane*; JACOBSON, Elliot; BRISETTE, Micahael; University of Alabama at Birmingham; University of Alabama at Birmingham; University of Florida; Quantum Resources, In Water Research twibbels@uab.edu

All sea turtles have temperature-dependent sex determination (TSD). This type of sex determination has the potential of producing biased sex ratios which are of ecological and evolutionary interest. The loggerhead sea turtle population inhabiting the coastal waters of the southeastern U.S. is one of the largest loggerhead populations in the world. The current study utilizes a testosterone-based sexing technique to evaluate juvenile sex ratios in this population. It is advantageous to evaluate juvenile sex ratios because they represent a condensation of many years of hatchling production. In the current study, several hundred juvenile loggerheads were captured at the St. Lucie Nuclear Power Plant on the Atlantic coast of Florida. This area represents a major nesting location and juvenile foraging ground for loggerheads. Blood samples were taken immediately after capture and the turtles were released into the Atlantic. A radioimmunoassay for testosterone was used to evaluate the sex of the captured turtles. Previous studies of sea turtle sex ratios indicate that TSD can produce a variety of sex ratios including significant biases. Further, a previous study of loggerheads in this same location over two decades ago indicated a significant female bias. The results of the current with are consistent with those of previous studies. The results provide insight on the temporal stability of the population’s sex ratio in a species with TSD. Further, the results have implications for ecological and evolutionary significance TSD.