%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Besnard, Lucien
%A Le Croizier, Gael
%A Sonke, J. E.
%A Galván-Magaña, F.
%A Trueman, C.
%A Martínez-Rincón, R. O.
%A Harrod, C.
%A Kraffe, E.
%A Point, David
%A Soto-López, K.
%A Schaal, G.
%T Using carbon, nitrogen, sulfur, and mercury isotopes to trace elasmobranch foraging habitats in contrasting biogeochemical environments
%D 2025
%L fdi:010094846
%G ENG
%J Environmental Science and Technology
%@ 0013-936X
%K trophic ecology ; isotopic niche ; Gulf of California ; Pacific Ocean ; shark ; ray ; biogeochemical processes ; upwelling
%K PACIFIQUE
%K CALIFORNIE GOLFE
%M ISI:001545773400001
%P [13 ]
%R 10.1021/acs.est.5c01680
%U https://www.documentation.ird.fr/hor/fdi:010094846
%> https://www.documentation.ird.fr/intranet/publi/2025-09/010094846.pdf
%V [Early access]
%W Horizon (IRD)
%X 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.
%$ 036