Open AccessStable isotopes as measure of niche breadth of nesting green turtles (Chelonia mydas) on Rocas Atoll, Brazil
Author(s) -
Karoline Fernanda Ferreira Agostinho,
Leandro R. Monteiro,
Carlos Eduardo Veiga de Carvalho,
Ana Paula Madeira Di Beneditto
Publication year - 2021
Publication title -
revista ibero-americana de ciências ambientais
Language(s) - English
Resource type - Journals
ISSN - 2179-6858
DOI - 10.6008/cbpc2179-6858.2021.003.0008
Subject(s) - carapace , benthic zone , biology , trophic level , ecology , turtle (robot) , niche , population , isotope analysis , sea turtle , fishery , crustacean , demography , sociology
The study analysed the niche breadth of nesting green turtles, Chelonia mydas, on Rocas Atoll, Brazil, through stable isotopes (δ15N and δ13C), comparing samplings of egg yolk and carapace collected from two nesting groups (2017 and 2019). The mean δ15N values in egg yolk and carapace were 7.1‰ (2017) and 6.8‰ (2019), and 7.8‰ (2017) and 7.3‰ (2019), respectively. For δ13C, the mean values were -17.4‰ (2017) and -17.5‰ (2019) in egg yolk, and -18.4‰ (2017) and -17.9‰ (2019) in carapace. The results suggest herbivory in coastal-benthic environments as the main feeding pattern in this nesting population. The niche breadth was similar between 2017 and 2019 in both tissues. In general, the trophic diversity (NR, CR, CD and SEA) was comparable between years as well as the trophic redundancy (MNND and SDNND), which was overall high. The niche metrics pointed to a homogeneous feeding pattern in the two nesting groups (2017 and 2019). This study adds a piece to solve the puzzle of adult green turtle trophic ecology.