%0 Journal Article
%T Reconstructing sea turtle ontogenetic habitat shifts through trace element analysis of bone tissue
%A Eric Parks
%A Jeffrey A. Seminoff
%A Jessica A. Miller
%A Larisa Avens
%A Lisa R. Goshe
%A Matthew D. Ramirez
%A Melissa L. Snover
%A Selina S. Heppell
%J Marine Ecology Progress Series (MEPS)
%@ 1616-1599
%D 2018
%R 10.3354/meps12796
%X ABSTRACT: Trace element analysis has emerged as a powerful tool to elucidate past movement and habitat use in aquatic animals, but has been underutilized in studies of non-fish species. When applied to sequentially deposited tissues (e.g. fish otoliths, sea turtle humerus bone), the technique can be used to infer aspects of an individual¡¯s ecology through time. The goal of this study was to evaluate whether trace elements could be used to reconstruct transitions between oceanic and neritic life stages in 2 species of sea turtle. We sampled the annual humerus bone growth layers of loggerhead Caretta caretta and Kemp¡¯s ridley Lepidochelys kempii sea turtles for concentrations of 7 elements (Mg, Ca, Mn, Cu, Zn, Sr, Ba) using laser ablation-inductively coupled plasma-mass spectrometry. Previous studies have demonstrated that stable nitrogen isotope (¦Ä15N) values can be used to reconstruct ontogenetic shifts between oceanic (offshore) and neritic (nearshore) habitats in these species; therefore, bone ¦Ä15N data were also collected for comparison. Bone strontium to calcium (Sr:Ca) and barium to calcium (Ba:Ca) ratios were significantly higher in oceanic versus neritic life stages for both species. Changes in bone elemental ratios within individuals coincided with known changes in resource use, as indicated by ¦Ä15N values, and fell within the range of body sizes and ages typical for oceanic-to-neritic ontogenetic shifts in each species. We conclude that bone Sr:Ca and Ba:Ca ratios may identify oceanic versus neritic resource use in sea turtles, but that additional studies are needed to identify the specific mechanisms underpinning these differences.
%U https://www.int-res.com/abstracts/meps/v608/p247-262/