Title
You are what you eat and where you eat it: Interpreting the isotopic niche of the Caribbean green turtle
Author(s)
Vander Zanden, Hannah B.; Arthur, Karen; Bolten, Alan B.; Popp, Brian N.; Lagueux, Cynthia J.; Harrison, Emma C.; Campbell, Cathi L.; Bjorndal, Karen A.
Published
2023
Published Version DOI
https://doi.org/10.25923/pc94-bm94
Abstract
We investigate the trophic ecology and spatial distribution of green turtles (Chelonia mydas) in the Caribbean through stable isotope analysis. The isotopic niche is a proxy for the ecological niche encompassing the diet and habitat resources used by a consumer, and has become a tool to identify differences among or within populations. We assess the trophic and spatial contributions to carbon and nitrogen isotope values in the aggregate nesting population at Tortuguero, Costa Rica. We compare the isotopic niche of the nesting population to that of five foraging grounds. We evaluate variability in trophic position and differences in isotopic compositions of primary producers using analyses of the primary diet item Thalassia testudinum from the Greater Caribbean and using compound-specific stable isotope analysis of amino acids in a subset of the nesting population. The nesting population had greater isotopic variability resulting in a larger isotopic niche compared to each of the foraging grounds. The combined results indicate that the population likely feeds at the same trophic level, while geographic differences in the isotopic compositions at the base of the food web contribute to the isotopic variation in the nesting population. These spatial differences also allow us to estimate the proportion of the nesting population using a specific foraging area. This study can be useful in better understanding the foraging ecology of highly dispersed and migratory populations.

Access Full Text


Back

DMX4995500000