Baseline
Mercury concentrations, biomagnification and isotopic discrimination factors in two seabird species from the Humboldt Current ecosystem

https://doi.org/10.1016/j.marpolbul.2022.113481Get rights and content

Highlights

  • Hg levels, biomagnification and isotopic discrimination factors in Humboldt seabirds

  • BMFs, Δ13C and Δ15N differed from other seabirds previously studied.

  • Lower Hg concentrations in Humboldt seabirds compared to other regions

  • Potential Hg biodilution in the high biomass of the first trophic levels

Abstract

Assessing mercury (Hg) biomagnification requires the description of prey-predator relationships, for each species and ecosystem, usually based on carbon and nitrogen isotope analyses. Here, we analyzed two seabirds from the Humboldt Current ecosystem, the Guanay cormorant (Phalacrocorax bougainvillii) and the Peruvian booby (Sula variegata), as well as their main prey, the Peruvian anchovy (Engraulis ringens). We reported Hg concentrations, Hg biomagnification (BMF) and isotopic discrimination factors (Δ13C and Δ15N) in seabird whole blood. BMFs and Δ13C in our study (on wild birds where diet was not controlled) were similar to other piscivorous seabirds previously studied in captive settings, but Δ15N were lower than most captive experiments. We observed lower Hg concentrations in Humboldt seabirds compared to other oligotrophic ecosystems, possibly due to Hg biodilution in the high biomass of the first trophic levels. This work calls for a better characterization of Hg trophic dynamics in productive upwelling ecosystems.

Section snippets

CRediT authorship contribution statement

Gaël Le Croizier: Conceptualization, Methodology, Formal analysis, Writing – original draft, Writing – review & editing. David Point: Resources, Writing – review & editing, Supervision, Funding acquisition. Marina Renedo: Formal analysis, Writing – review & editing. Jean-Marie Munaron: Formal analysis, Writing – review & editing. Pepe Espinoza: Resources, Writing – review & editing. Felipe Amezcua-Martinez: Writing – review & editing. Sophie Lanco Bertrand: Resources, Writing – review &

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This work was supported by the cooperative agreement between the Institut de Recherche pour le Développement (IRD), the Peruvian Sea Institute (IMARPE), the Agence Nationale de la Recherche (ANR) project ‘Top Predators as Indicators of Exploited Marine Ecosystem dynamics’ (TOPINEME, PI SB), and the International Joint Laboratory DISCOH 1&2 for sample collection, and funding for carbon and nitrogen isotope and mercury concentration analysis. We thank Gaël Guillou for carbon and nitrogen stable

References (65)

  • J. Giménez et al.

    From the pool to the sea: applicable isotope turnover rates and diet to skin discrimination factors for bottlenose dolphins (Tursiops truncatus)

    J. Exp. Mar. Biol. Ecol.

    (2016)
  • M. Gochfeld

    Mercury levels in some seabirds of the Humboldt Current, Peru

    Environ. Pollut. Ser. A Ecol. Biol.

    (1980)
  • E. Ha et al.

    Current progress on understanding the impact of mercury on human health

    Environ. Res.

    (2017)
  • A.L. Hargreaves et al.

    Concentrations of 17 elements, including mercury, in the tissues, food and abiotic environment of Arctic shorebirds

    Sci. Total Environ.

    (2011)
  • N.E. Hussey et al.

    δ15N and δ13C diet–tissue discrimination factors for large sharks under semi-controlled conditions

  • N.E. Hussey et al.

    Expanded trophic complexity among large sharks

    Food Webs

    (2015)
  • M. Lerma et al.

    Lead, cadmium and mercury in the blood of the blue-footed booby (Sula nebouxii) from the coast of Sinaloa, Gulf of California, Mexico

    Mar. Pollut. Bull.

    (2016)
  • G. López-Berenguer et al.

    A critical review about neurotoxic effects in marine mammals of mercury and other trace elements

    Chemosphere

    (2020)
  • M.A. McKinney et al.

    Global versus local causes and health implications of high mercury concentrations in sharks from the east coast of South Africa

    Sci. Total Environ.

    (2016)
  • A. Médieu et al.

    Lipid-free tuna muscle samples are suitable for total mercury analysis

    Mar. Environ. Res.

    (2021)
  • J. Seco et al.

    Mercury biomagnification in a Southern Ocean food web

    Environ. Pollut.

    (2021)
  • J. Tam et al.

    Trophic modeling of the Northern Humboldt Current Ecosystem, Part I: comparing trophic linkages under La Niña and El Niño conditions

  • M.J. Adkesson et al.

    Analysis of toxic and essential elements in the blood and feathers of Humboldt penguins (Spheniscus humboldti) at Punta San Juan, Peru

    J. Wildl. Dis.

    (2019)
  • C. Barbraud et al.

    Density dependence, prey accessibility and prey depletion by fisheries drive Peruvian seabird population dynamics

    Ecography

    (2018)
  • S. Bearhop et al.

    Dynamics of mercury in blood and feathers of great skuas

    Environ. Toxicol. Chem.

    (2000)
  • S. Bearhop et al.

    Factors that influence assimilation rates and fractionation of nitrogen and carbon stable isotopes in avian blood and feathers

    Physiol. Biochem. Zool.

    (2002)
  • G.L. van den Berg et al.

    Decadal shift in foraging strategy of a migratory southern ocean predator

    Glob. Chang. Biol.

    (2021)
  • J.D. Blum et al.

    Methylmercury production below the mixed layer in the North Pacific Ocean

    Nat. Geosci.

    (2013)
  • A.L. Bond et al.

    Recent Bayesian stable-isotope mixing models are highly sensitive to variation in discrimination factors

    Ecol. Appl.

    (2011)
  • C.A. Caldwell et al.

    Mercury distribution in blood, tissues, and feathers of double-crested cormorant nestlings from arid-lands reservoirs in South Central New Mexico

    Arch. Environ. Contam. Toxicol.

    (1999)
  • S. Caut et al.

    Variation in discrimination factors (Δ15N and Δ13C): the effect of diet isotopic values and applications for diet reconstruction

    J. Appl. Ecol.

    (2009)
  • Y. Cherel et al.

    Isotopic discrimination between food and blood and feathers of captive penguins: implications for dietary studies in the wild

    Physiol. Biochem. Zool.

    (2005)
  • Cited by (9)

    View all citing articles on Scopus
    View full text