Establishment and Growth of a Sea Turtle Rookery: The Population Biology of the Leatherback in Florida
Kelly Stewart, Duke University Marine Laboratory
21 Sep 2007
Despite facing serious threat of extirpation in the Eastern Pacific, the critically endangered leatherback (Dermochelys coriacea) appears to be thriving in the Atlantic. This work establishes a critical baseline of biological data for the leatherback at the northern limit of its nesting range in the northwestern Atlantic (Florida). Four major objectives of the Federal (US) Leatherback Recovery Plan for the east coast of Florida were addressed. 1) Using a multilevel modeling approach, I found an increase of 11.3 ± 1.9% each year in the number of nests since 1979. 2) By tagging and recapturing individual females, the annual survival rate (95.6%) and nesting population size was determined. 3) I used novel GPS tags and tag returns to discover the full nesting range and true clutch frequency of individual turtles. Leatherbacks in Florida nest at broad spatial scales, distributing at least five nests within a single season up to 139.8 km from first encounter. 4) Finally, I used microsatellites and mtDNA to determine the relatedness of this population and found evidence for ongoing migration from Caribbean rookeries. Although the Florida population is relatively small, it has the potential to contribute to further increases of leatherbacks in the Atlantic, thereby achieving objectives of the US Recovery Plan.