Evaluating Environmental and Climatic Influences on Nesting in Leatherback Sea Turtles (Dermochelys coriacea) in St. Kitts, West Indies

Abstract

Leatherback sea turtles (Dermochelys coriacea) are endangered throughout their range. To protect these animals, research is needed to develop conservation programs that protect the turtles during all of their life stages, including foraging, breeding, nesting, and hatching. The purpose of this study was to focus on issues related to nesting by determining if environmental and climatic factors influence nesting for female leatherback sea turtles. A variety of climatic and environmental samples were collected during the nesting season from May-July 2008. Data was collected during nesting events and non-nesting events for comparison. Sea turtles were found to be significantly more likely to nest during the later lunar phases (p = 0.001) and when cloud cover was low (less than 50%) over the natal beaches (p = 0.02). Sand conductivity was significantly lower (p=0.008) at the nesting level of the sand compared with the surface sand (0.09 microS/cm). There were also significant differences in the pH (p=0.001) of the sand taken at control surfaces and nesting surfaces along with significant difference between the control samples taken from nest depth as compared to turtle nests in pH (p= 0.020), temperature (p= 0.037), and sand grain size (p= 0.001). These findings suggest that select climatic and environment factors do vary between nesting and non-nesting sites in this species, and it is possible that these differences could ultimately influence when and where the turtles deposit their eggs. This information should be considered when developing conservation plans for this species, including habitat management and personnel use during the nesting season.