Large‐scale patterns of green turtle trophic ecology in the eastern Pacific Ocean

Trophic position and niche width are fundamental components of a species’ ecology, reflecting resource use, influencing key demographic parameters such as somatic growth, maturation, survival. Concepts about trophic space have important implications for local management habitat protection, can shed light resilience to changing climate species occurring over broad spatial scales. For elusive marine animals sea turtles, is challenging study, researchers often rely on other metrics, isotopic niche, proxy. Here, stable isotope analysis (δ13C δ15N values) was conducted bulk skin tissue 718 green turtles (Chelonia mydas) distributed among 16 foraging areas in the eastern Pacific from USA Chile, range spanning ~10,000 km. Compound-specific nitrogen amino acids (CSIA-AA) applied 21 seven sites. Isotopic determined via Bayesian ellipse area (BEA) convex hull (CHA) analyses values, which were also used along with acid values determine (TP). Substantial variability δ13C found within sites, confirmed this largely due differences baseline compositions, but lesser extent TP turtle populations. Isotope varied influenced by diversity prey types relative input terrestrial- vs. marine-derived nutrients; BEAs most suitable measurement larger influence outlying CHA approach. Amino isotope-derived estimates that accounted conditions (e.g., mixed seagrass/macroalgae diet) performed best several approaches; ranged 2.3 3.6, indicates an omnivorous diet In addition providing additional resolution isoscapes Pacific, especially coastal habitats, study further establishes CSIA-AA effective tool ecology across variety food webs habitats.