Articles | Volume 12, issue 23
Research article
08 Dec 2015
Research article |  | 08 Dec 2015

Stable isotopes in barnacles as a tool to understand green sea turtle (Chelonia mydas) regional movement patterns

M. Detjen, E. Sterling, and A. Gómez

Abstract. Sea turtles are migratory animals that travel long distances between their feeding and breeding grounds. Traditional methods for researching sea turtle migratory behavior have important disadvantages, and the development of alternatives would enhance our ability to monitor and manage these globally endangered species. Here we report on the isotope signatures in green sea-turtle (Chelonia mydas) barnacles (Platylepas sp.) and discuss their potential relevance as tools with which to study green sea turtle migration and habitat use patterns. We analyzed oxygen (δ18O) and carbon (δ13C) isotope ratios in barnacle calcite layers from specimens collected from green turtles captured at the Palmyra Atoll National Wildlife Refuge (PANWR) in the central Pacific. Carbon isotopes were not informative in this study. However, the oxygen isotope results suggest likely regional movement patterns when mapped onto a predictive oxygen isotope map of the Pacific. Barnacle proxies could therefore complement other methods in understanding regional movement patterns, informing more effective conservation policy that takes into account connectivity between populations.

Short summary
We report on the oxygen isotope signatures in green sea turtle (Chelonia mydas) barnacles (Platylepas sp.) to suggest likely regional movement patterns by mapping these onto a predictive oxygen isotope map of the Pacific. Exploring barnacle proxies potential relevance as an alternative tool with which to study green sea turtle migration, we find that these could complement traditional methods of studying connectivity between turtle populations and help inform more effective conservation policy.
Final-revised paper