Meeting Abstract
Many environmental variables affect the early development of incubating eggs. The effects of temperature on loggerhead sea turtle (Caretta caretta) eggs are often considered in understanding developmental factors such as incubation duration and sex ratios. Until recently, the role of sand moisture has been studied little, but recent work showed that increased moisture in the field may affect sexual differentiation and embryonic development. We hypothesize that loggerhead neonate growth rate may also be impacted by variable moisture. Growth rates and emergence success for natural (in situ) and experimental nests were studied during the 2015 nesting season. Each nest was classified incubating earlier in the nesting season (hot dry conditions) and later in the nesting season (hot wet conditions). In an experimental field study we divided clutches in half and reburied them. One half-clutch of the pair received ambient rainfall (“dry”) while the other half-clutch received ambient rainfall plus daily watering (“wet”). Data loggers monitored incubation temperatures. Upon emerging, turtles were raised in the lab for several months until reaching ~120 g. Weekly mass, straight carapace length (SCL), straight carapace width (SCW), and body depth (BD) measurements were taken and growth/day calculated. Mann-Whitney U tests compared median growth rate for dry versus wet neonates for natural and experimental nests. Turtles from wet nests grew faster in SCL and mass but not SCW and BD. Emergence success was higher for wet nests. Given concerns about increasing temperature and shifting rainfall patterns along Florida coastline due to climatic change these results highlight how varying weather patterns may have otherwise cryptic effects on marine turtles.
