Meeting Abstract

P1.6  Tuesday, Jan. 4  Loggerhead Turtle Nest Metabolism and Gas Exchange in Greece SUSS, J.S.*; O’CONNOR, M.P.; SPOTILA, J.R.; Drexel University, Philadelphia, PA; Drexel University, Philadelphia, PA; Drexel University, Philadelphia, PA jss27@drexel.edu

Metabolism is important to embryonic development in oviparous reptiles and is influenced by gas exchange, hydric and thermal conditions, and nest density. Many reptiles deposit their eggs underground where gas exchange is limited by the diffusive properties of the substrate. The clutch of eggs acts as an oxygen sink and a carbon dioxide source. Loggerhead turtles bury their clutches 40 cm in the beaches along Laganas Bay, Zakynthos and southern Kyparissia Bay, Western Peleponnese, Greece. Since these nests cannot move, the air and water in the sand immediately surrounding the nest influences metabolism. These beaches provide a wide range of sand particle size distributions from fine sand to coarse sand that contribute to differences in gas flow and water potential. Measurements of the physical characteristics of the sand on these beaches, and the temperature, oxygen, and carbon dioxide levels in nests allow us to understand the limitations of gas exchange on sea turtle nests. Nest temperatures also differ among the beaches, influencing sex ratios and incubation duration. Additionally, the beaches differ in nest densities; nests very close together share respiratory space and influence gas concentrations. The summer in Greece is very dry, and as such, the dry front can reach the top eggs in a shallow nest affecting the nest hydration. During incubation, oxygen decreases and carbon dioxide increases in the nests until hatch. That the eggs in loggerhead nests are able to develop under a wide range of environments speaks to the importance of adaptive plasticity during activity-limited life stages.