Stable isotope discrimination (δ13C and δ15N) between soft tissues of the green sea turtle Chelonia mydas and its diet
Year: 2006
Type: article
Abstract: The foraging ecology and movements of vertebrate species have been increasingly studied via stable isotope analyses of small quantities of body tissues.However, the theoretical and experimental basis of this method remains poorly validated for most taxa despite numerous studies using these techniques in natural systems.In this study, we measured stable carbon and stable nitrogen diet -tissue discrimination (Δ dt ) in whole blood, red blood cells, blood plasma, and epidermis of 8 captive green turtles Chelonia mydas maintained on a control diet (41% protein, 12% lipids, 4% fiber) for 619 d.During the course of the study, mean straight carapace length increased from 45.2 ± 1.2 to 53.7 ± 2.1 cm, whereas mean body mass increased from 11.7 ± 0.7 to 19.9 ± 2.2 kg.Both diet and tissue isotope values remained constant throughout the study, indicating that diet -tissue equilibrium had been achieved.Whereas Δ dt 13 C ranged from -1.11 ‰ (red blood cells) to + 0.17 ‰ (epidermis), Δ dt 15 N ranged from + 0.22 ‰ (red blood cells) to + 2.92 ‰ (blood plasma).These results contrast with the widely accepted discrimination factors of 0 to 1 ‰ for δ 13 C and 3 to 5 ‰ for δ 15 N. Comprising the initial enrichment factors available for green turtles, these data will be useful in future interpretations of field isotopic values for this species.
Source: Marine Ecology Progress Series
DOI: 10.3354/meps308271
Authors: JA Seminoff, TT Jones, T Eguchi, DR Jones, PH Dutton
Language: English
Topic: Isotope Analysis in Ecology
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1968318776