Journal article
Foraging plasticity diversifies mercury exposure sources and bioaccumulation patterns in the world's largest predatory fish
Journal of Hazardous Materials, Vol.425, pp.1-9
05/03/2022
PMID: 34986563
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Source: InCites
Abstract
Large marine predators exhibit high concentrations of mercury (Hg) as neurotoxic 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 Δ200Hg signatures in shark tissues, we found that atmospheric Hg deposition pathways to the marine environment differed between coastal and offshore habitats. Discrepancies in δ202Hg and Δ199Hg 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.
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•Mercury (Hg) isotopes were analyzed in three white shark populations.•Δ200Hg values showed different atmospheric Hg deposition pathways across habitats.•Δ199Hg and δ202Hg values indicated population variations in marine Hg exposure.•Hg concentrations in adult sharks differed by a factor of three between populations.•Hg contamination in ocean predators may not vary uniformly under global change.
Details
- Title
- Foraging plasticity diversifies mercury exposure sources and bioaccumulation patterns in the world's largest predatory fish
- Creators
- Gaël Le Croizier - Observatoire Midi-PyrénéesJeroen E Sonke - Observatoire Midi-PyrénéesAnne Lorrain - Université Bretagne de OccidentaleMarina Renedo - Observatoire Midi-PyrénéesMauricio Hoyos-Padilla - Pelagios-Kakunjá A.C.Omar Santana-Morales - ECOCIMATI A.C., 22800 Ensenada, Baja California, MexicoLauren Meyer - Flinders UniversityCharlie Huveneers - Flinders UniversityPaul Butcher - NSW Department of Primary IndustriesFelipe Amezcua-Martinez - Universidad Nacional Autónoma de MéxicoDavid Point - Observatoire Midi-Pyrénées
- Publication Details
- Journal of Hazardous Materials, Vol.425, pp.1-9
- Publisher
- Elsevier BV
- Grant note
- Gaël Le Croizier was supported by a postdoctoral grant from the French National Research Institute for Sustainable Development (IRD) and the ISblue "Interdisciplinary graduate School for the blue planet" project (ANR-17-EURE-0015). We thank the French National Research Agency ANR-17-CE34-0010 project ‘Unraveling the origin of methylMERcury TOXin in marine ecosystems’ (MERTOX, PI DP) for providing financial support for Hg isotope analysis. The project was funded in Mexico by Alianza WWF-TELCEL, The Annemberg Foundation, International Community Foundation, Fins Attached Marine Research and Conservation and Pfleger Institute of Environmental Research. We also thank the Save Our Seas Foundation, Holsworth Wildlife Research Endowment (HWRE2016R2098), Oceania Chondrichthyan Society and Passions of Paradise for providing funding to support sample collection.
- Identifiers
- 991012988297002368
- Copyright
- © 2021 Elsevier B.V. All rights reserved.
- Academic Unit
- Faculty of Science and Engineering; Science; National Marine Science Centre
- Language
- English
- Resource Type
- Journal article