Publications des scientifiques de l'IRD

Le Croizier Gael, Sonke J. E., Lorrain Anne, Renedo M., Hoyos-Padilla M., Santana-Morales O., Meyer L., Huveneers C., Butcher P., Amezcua-Martinez F., Point David. (2022). Foraging plasticity diversifies mercury exposure sources and bioaccumulation patterns in the world's largest predatory fish. Journal of Hazardous Materials, 425, 127956 [9 p.]. ISSN 0304-3894.

Titre du document
Foraging plasticity diversifies mercury exposure sources and bioaccumulation patterns in the world's largest predatory fish
Année de publication
2022
Type de document
Article référencé dans le Web of Science WOS:000734372600003
Auteurs
Le Croizier Gael, Sonke J. E., Lorrain Anne, Renedo M., Hoyos-Padilla M., Santana-Morales O., Meyer L., Huveneers C., Butcher P., Amezcua-Martinez F., Point David
Source
Journal of Hazardous Materials, 2022, 425, 127956 [9 p.] ISSN 0304-3894
Large marine predators exhibit high concentrations of mercury (Hg) as neumtoxic methylmercury, and the potential impacts of global change on Hg contamination in these species remain highly debated. Current contaminant model predictions do not account for intraspecific variability in Hg exposure and may fail to reflect the diversity of future Hg levels among conspecific populations or individuals, especially for top predators displaying a wide range of ecological traits. Here, we used Hg isotopic compositions to show that Hg exposure sources varied significantly between and within three populations of white sharks (Carcharodon carcharias) with contrasting ecology: the north-eastern Pacific, eastern Australasian, and south-western Australasian populations. Through Delta Hg-200 signatures in shark tissues, we found that atmospheric Hg deposition pathways to the marine environment differed between coastal and offshore habitats. Discrepancies in delta Hg-202 and Delta Hg-199 signatures among white sharks provided evidence for intraspecific exposure to distinct sources of marine methylmercury, attributed to population and ontogenetic shifts in foraging habitat and prey composition. We finally observed a strong divergence in Hg accumulation rates between populations, leading to three times higher Hg concentrations in large Australasian sharks compared to north-eastern Pacific sharks, and likely due to different trophic strategies adopted by adult sharks across populations. This study illustrates the variety of Hg exposure sources and bioaccumulation patterns that can be found within a single species and suggests that intraspecific variability needs to be considered when assessing future trajectories of Hg levels in marine predators.
Plan de classement
Limnologie biologique / Océanographie biologique [034] ; Pollution [038]
Description Géographique
ATLANTIQUE ; OCEAN INDIEN ; MEXIQUE ; AUSTRALIE
Localisation
Fonds IRD [F B010083892]
Identifiant IRD
fdi:010083892
Contact