Sea Turtle Feeding Patterns

Understanding sea turtle movement and feeding

This project uses stable isotope ratios of nitrogen (d15N), carbon (d13C), sulfur (d34S), and oxygen (d18O) to trace the movement and feeding patterns of Atlantic Green (Chelonia mydas) and Loggerhead (Caretta caretta) sea turtles from nesting beaches in northeast Florida. Carbon, nitrogen, and sulfur isotope ratios will be compared to published known ratios of a variety of oceanic pelagic and benthic species that are in the prey portfolio of sea turtles in the region (Godley, 1998). The ratios of carbon, sulfur, and nitrogen in the eggshell, albumen, and yolk material will be used to determine the trophic feeding levels and the source input regions. The oxygen and carbon isotopes will be used to determine the movements of the nesting female using differences in oxygen isotope values in surface waters and the regional carbon values in prey species of the open Atlantic Ocean and near eastern United States coastal regions (Godley, 1998; Barrow, 2006). Analysis is currently underway with the support of the Stable Isotope Lab, under Dr. Peter Swart, at the Rosenstiel School of Marine and Atmospheric Science. This understanding will aid in conservation and management that could better the regions to help ensure successful nesting and hatching of the sea turtles nesting on northeast Florida beaches.

Kaitlyn Dietz

Marine Biology

Graduate Student, Jacksonville University