technique for capturing sea turtles. Turtles were bled 

 immediately after capture and were then taken to Heron Island 

 where they were laparoscopically examined. During that study, we 

 laparoscopically examined 60 immature loggerheads (sex ratio = 

 3.6 M:1.0F), 26 immature hawksbills (sex ratio = 4.2F:1.0M), and 

 2 00 greens (sex ratio = 2.0F:1.0M). In each of the species 

 examined (with the exception of one male green turtle) the serum 

 testosterone titers of the males were always higher than those of 

 the females. Therefore, these data indicate that serum 

 testosterone is an accurate indicator of a sea turtle's sex and 

 it could be used as a conservation tool for studying population 

 sex ratios. However, to use this technique effectively one must 

 1) be capable of processing blood samples in the field (i.e., 

 centrifuging and freezing) and 2) have access to a sensitive 

 radioimmunoassay for testosterone (sensitive down to 

 approximately 5 picograms) . 



350 



