Leatherback turtles (Dermochelys coriacea) are critically endangered, largely due to a variety of human activities. While many aspects of their life history are documented, there is virtuallynothing known about survival of hatchlings during their first hours at sea. It is widely thought that most mortality occurs very early in the life of sea turtles. The pattern of this early survival influences whether offshore release could provide a conservation benefit. We tracked leatherback hatchlings leaving Playa Grande, Costa Rica and observed the mortality rate of the hatchlings at different distances from shore (0, 1, 2, 4, and 8km). Our sample size at any given distance is small, precluding significance testing for effects of distance from shore, but predation rates appear to be greatest near shore (0-2km), then to decline precipitously. Moonlight has a significant effect on survival, with predation far more likely when the moon is up. While the results suggest that offshore release may substantially enhance survival, we need more data before promoting offshore release as a conservation tool.
Emily Wachutka, ’08 Kaneohe, HI
Erin Lappen, ’08 Chanhassen, MN
Majors: Biology, Environmental Studies
Sponsor: S. Andrew McCollum