Stable isotope discrimination factors and between-tissue isotope comparisons for bone and skin from captive and wild green sea turtles (Chelonia mydas)
| Autor: | Calandra N. Turner Tomaszewicz, Jeffrey A. Seminoff, Carolyn M. Kurle, Mike Price |
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| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
Male Zoology Captivity Animals Wild 010603 evolutionary biology 01 natural sciences Bone and Bones Mass Spectrometry Article Analytical Chemistry Animals Mexico Spectroscopy Isotope analysis Skin Carbon Isotopes Pacific Ocean δ13C Isotope Nitrogen Isotopes Chemistry Stable isotope ratio 010604 marine biology & hydrobiology Organic Chemistry δ15N Isotopes of nitrogen Turtles Isotopes of carbon Linear Models Animals Zoo |
| Zdroj: | Rapid communications in mass spectrometry : RCM. 31(22) |
| ISSN: | 1097-0231 |
| Popis: | RATIONALE The ecological application of stable isotope analysis (SIA) relies on taxa- and tissue-specific stable carbon (Δ13C) and nitrogen (Δ15N) isotope discrimination factors, determined with captive animals reared on known diets for sufficient time to reflect dietary isotope ratios. However, captive studies often prohibit lethal sampling, are difficult with endangered species, and reflect conditions not experienced in the wild. METHODS We overcame these constraints and determined the Δ13C and Δ15N values for skin and cortical bone from green sea turtles (Chelonia mydas) that died in captivity and evaluated the utility of a mathematical approach to predict discrimination factors. Using stable carbon (δ13C values) and nitrogen (δ15N values) isotope ratios from captive and wild turtles, we established relationships between bone stable isotope (SI) ratios and those from skin, a non-lethally sampled tissue, to facilitate comparisons of SI among studies using multiple tissues. RESULTS The mean (±SD) Δ13C and Δ15N values (‰) between skin and bone from captive turtles and their diet (non-lipid extracted) were 2.3±0.3 and 4.1±0.4 and 2.1±0.6 and 5.1±1.1, respectively. The mathematically predicted Δ13C and Δ15N values were similar (within 1‰) to the experimentally derived values. The mean δ15N values from bone were higher than those from skin for captive (+1.0±0.9‰) and wild (+0.8±1.0‰) turtles; the mean δ13C values from bone were lower than those from skin for wild turtles (–0.6±0.9‰), but the same as for captive turtles. We used linear regression equations to describe bone vs skin relationships and create bone-to-skin isotope conversion equations. CONCLUSIONS For sea turtles, we provide the first a) bone-diet SI discrimination factors, b) comparison of SI ratios from individual-specific bone and skin, and c) evaluation of the application of a mathematical approach to predict stable isotope discrimination factors. Our approach opens the door for future studies comparing different tissues, and relating SI ratios of captive to wild animals. |
| Databáze: | OpenAIRE |
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