Besnard Lucien, Le Croizier Gael, Sonke J. E., Galván-Magaña F., Trueman C., Martínez-Rincón R. O., Harrod C., Kraffe E., Point David, Soto-López K., Schaal G. (2025). Using carbon, nitrogen, sulfur, and mercury isotopes to trace elasmobranch foraging habitats in contrasting biogeochemical environments. Environmental Science and Technology, [Early access], [13 p.]. ISSN 0013-936X.
Titre du document
Using carbon, nitrogen, sulfur, and mercury isotopes to trace elasmobranch foraging habitats in contrasting biogeochemical environments
Année de publication
2025
Auteurs
Besnard Lucien, Le Croizier Gael, Sonke J. E., Galván-Magaña F., Trueman C., Martínez-Rincón R. O., Harrod C., Kraffe E., Point David, Soto-López K., Schaal G.
Source
Environmental Science and Technology, 2025,
[Early access], [13 p.] ISSN 0013-936X
Stable isotopes are well established as routine and reliable tracers of nutrient flux and trophic structure. However, inferring trophic ecology from isotopic data is challenging due to variability at the food web base and systematic differences in biochemical fractionation during metabolism. Analyses of isotope systems from multiple elements with contrasting fractionation drivers may resolve some sources of variance, strengthening connections between measured isotopic variations and inferred ecological processes. This study combines carbon (delta 13C), nitrogen (delta 15N), sulfur (delta 34S), and mercury (Delta 199Hg/delta 202Hg) isotopes to investigate trophic niches of coastal and oceanic elasmobranchs across two ecosystems in northwestern Mexico. In the Pacific Ocean, similar delta 13C, delta 15N, Delta 199Hg, and delta 202Hg values suggest that elasmobranchs relied on common pelagic resources, likely from upwelling events. In the Gulf of California, coastal species with higher delta 13C and delta 15N values and lower Delta 199Hg and delta 202Hg values fed on prey isotopically distinct from those offshore, allowing classification trees to identify foraging habitats more accurately than in the Pacific. Meanwhile, delta 34S values systematically decreased from oceanic to coastal species at both sites and were highlighted as the most discriminative isotopic tracer by random forests. This study advocates for integrating complementary isotopic analyses to better comprehend biogeochemical and ecological mechanisms.
Plan de classement
Ecologie, systèmes aquatiques [036]
Description Géographique
PACIFIQUE
Localisation
Fonds IRD [F B010094846]
Identifiant IRD
fdi:010094846
