eDNA metabarcoding for diet analyses of green sea turtles (Chelonia mydas)

Green sea turtles (Chelonia mydas) in the Bijagós Archipelago primarily consume red macroalgae, particularly from the Rhodymeniophycidae subclass, with incidental ingestion of diatoms. This dietary pattern was revealed using a novel, minimally invasive eDNA metabarcoding method targeting the 18S rRNA gene on esophageal and cloacal swab samples. Esophageal samples showed higher dietary richness (11 ± 5 ASVs) compared to cloacal ones (8 ± 2 ASVs), confirming feeding behavior through environmental DNA analysis. The study validates this approach as a powerful tool for understanding sea turtle trophic ecology, particularly in complex or inaccessible foraging habitats.

Díaz-Abad, L., Bacco-Mannina, N., Madeira, F. M., Neiva, J., Aires, T., Serrao, E. A., Regalla, A., Patrício, A. R., & Frade, P. R. (2021). eDNA metabarcoding for diet analyses of green sea turtles (Chelonia mydas). Marine Biology, 169(1). https://doi.org/10.1007/s00227-021-04002-x