Hg-Stable Isotope Variations in Marine Top Predators of the Western Arctic Ocean
International audience Recent studies on mercury (Hg)-stable isotopes in Alaskan seabird eggs and ringed seal livers illustrated the control of sea ice cover on marine methyl-Hg photochemistry. Here, complementary marine mammal tissues have been analyzed to document variations in Hg-, carbon (C)-, a...
Published in: | ACS Earth and Space Chemistry |
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Main Authors: | , , , , , |
Other Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2018
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Online Access: | https://hal.archives-ouvertes.fr/hal-01814156 https://doi.org/10.1021/acsearthspacechem.8b00017 |
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Open Polar |
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Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
Arctic isotopes mammals mercury MIF [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry [CHIM.ANAL]Chemical Sciences/Analytical chemistry [CHIM.POLY]Chemical Sciences/Polymers [CHIM.MATE]Chemical Sciences/Material chemistry |
spellingShingle |
Arctic isotopes mammals mercury MIF [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry [CHIM.ANAL]Chemical Sciences/Analytical chemistry [CHIM.POLY]Chemical Sciences/Polymers [CHIM.MATE]Chemical Sciences/Material chemistry Masbou, Jérémy Sonke, Jeroen, Amouroux, David Guillou, Gaël Becker, Paul, Point, David Hg-Stable Isotope Variations in Marine Top Predators of the Western Arctic Ocean |
topic_facet |
Arctic isotopes mammals mercury MIF [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry [CHIM.ANAL]Chemical Sciences/Analytical chemistry [CHIM.POLY]Chemical Sciences/Polymers [CHIM.MATE]Chemical Sciences/Material chemistry |
description |
International audience Recent studies on mercury (Hg)-stable isotopes in Alaskan seabird eggs and ringed seal livers illustrated the control of sea ice cover on marine methyl-Hg photochemistry. Here, complementary marine mammal tissues have been analyzed to document variations in Hg-, carbon (C)-, and nitrogen (N)-stable isotope compositions of Arctic marine food webs. Hg-stable isotope ratios were measured in liver samples of 55 beluga whales (Delphinapterus leucas) and 15 polar bears (Ursus maritimus) collected since 1990. Large variations in δ202Hg (≈2.1‰) and Δ199Hg (≈1.7‰) are observed between species and within species stocks covering the Gulf of Alaska-Bering Sea-Arctic Ocean regions. Polar bears, mainly feeding on ringed seal (δ15N shift of 4.2‰), show identical liver Δ199Hg of 0.5‰, confirming the absence of metabolic mass-independent fractionation, and 0.33 ± 0.11‰ enrichment in heavy Hg isotopes. Beluga whale liver total Hg concentrations increase with age, reflecting lifetime bioaccumulation, while Hg speciation shifts to inorganic Hg with age as a result of hepatic methyl-Hg breakdown. Δ200Hg variations in biota show a small, 0.1‰ decrease from North Pacific Ocean to Arctic Ocean habitats, suggesting atmospheric Hg deposition to be important in the Pacific and terrestrial Hg inputs to dominate in the Arctic Ocean. Similar to seabird eggs, a consistent south to north gradient in Δ199Hg baseline is seen in mammal liver tissues, confirming sea ice cover as a control factor on marine Hg photoreduction and Δ199Hg. Arctic Ocean beluga whales have near zero Δ199Hg, indicating that terrestrial Hg and in-situ-produced methyl-Hg are not measurably photoreduced in the Arctic Ocean before entering the marine food web |
author2 |
Géosciences Environnement Toulouse (GET) Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP) Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD) Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM) Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Masbou, Jérémy Sonke, Jeroen, Amouroux, David Guillou, Gaël Becker, Paul, Point, David |
author_facet |
Masbou, Jérémy Sonke, Jeroen, Amouroux, David Guillou, Gaël Becker, Paul, Point, David |
author_sort |
Masbou, Jérémy |
title |
Hg-Stable Isotope Variations in Marine Top Predators of the Western Arctic Ocean |
title_short |
Hg-Stable Isotope Variations in Marine Top Predators of the Western Arctic Ocean |
title_full |
Hg-Stable Isotope Variations in Marine Top Predators of the Western Arctic Ocean |
title_fullStr |
Hg-Stable Isotope Variations in Marine Top Predators of the Western Arctic Ocean |
title_full_unstemmed |
Hg-Stable Isotope Variations in Marine Top Predators of the Western Arctic Ocean |
title_sort |
hg-stable isotope variations in marine top predators of the western arctic ocean |
publisher |
HAL CCSD |
publishDate |
2018 |
url |
https://hal.archives-ouvertes.fr/hal-01814156 https://doi.org/10.1021/acsearthspacechem.8b00017 |
geographic |
Arctic Arctic Ocean Bering Sea Gulf of Alaska Pacific |
geographic_facet |
Arctic Arctic Ocean Bering Sea Gulf of Alaska Pacific |
genre |
Arctic Arctic Ocean Beluga Beluga whale Beluga* Bering Sea Delphinapterus leucas ringed seal Sea ice Ursus maritimus Alaska |
genre_facet |
Arctic Arctic Ocean Beluga Beluga whale Beluga* Bering Sea Delphinapterus leucas ringed seal Sea ice Ursus maritimus Alaska |
op_source |
ISSN: 2472-3452 ACS Earth and Space Chemistry https://hal.archives-ouvertes.fr/hal-01814156 ACS Earth and Space Chemistry, ACS, 2018, 2 (5), pp.479 - 490. ⟨10.1021/acsearthspacechem.8b00017⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1021/acsearthspacechem.8b00017 hal-01814156 https://hal.archives-ouvertes.fr/hal-01814156 doi:10.1021/acsearthspacechem.8b00017 |
op_doi |
https://doi.org/10.1021/acsearthspacechem.8b00017 |
container_title |
ACS Earth and Space Chemistry |
container_volume |
2 |
container_issue |
5 |
container_start_page |
479 |
op_container_end_page |
490 |
_version_ |
1766308383754813440 |
spelling |
ftccsdartic:oai:HAL:hal-01814156v1 2023-05-15T14:35:35+02:00 Hg-Stable Isotope Variations in Marine Top Predators of the Western Arctic Ocean Masbou, Jérémy Sonke, Jeroen, Amouroux, David Guillou, Gaël Becker, Paul, Point, David Géosciences Environnement Toulouse (GET) Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP) Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD) Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM) Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) 2018 https://hal.archives-ouvertes.fr/hal-01814156 https://doi.org/10.1021/acsearthspacechem.8b00017 en eng HAL CCSD ACS info:eu-repo/semantics/altIdentifier/doi/10.1021/acsearthspacechem.8b00017 hal-01814156 https://hal.archives-ouvertes.fr/hal-01814156 doi:10.1021/acsearthspacechem.8b00017 ISSN: 2472-3452 ACS Earth and Space Chemistry https://hal.archives-ouvertes.fr/hal-01814156 ACS Earth and Space Chemistry, ACS, 2018, 2 (5), pp.479 - 490. ⟨10.1021/acsearthspacechem.8b00017⟩ Arctic isotopes mammals mercury MIF [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry [CHIM.ANAL]Chemical Sciences/Analytical chemistry [CHIM.POLY]Chemical Sciences/Polymers [CHIM.MATE]Chemical Sciences/Material chemistry info:eu-repo/semantics/article Journal articles 2018 ftccsdartic https://doi.org/10.1021/acsearthspacechem.8b00017 2021-12-12T03:21:15Z International audience Recent studies on mercury (Hg)-stable isotopes in Alaskan seabird eggs and ringed seal livers illustrated the control of sea ice cover on marine methyl-Hg photochemistry. Here, complementary marine mammal tissues have been analyzed to document variations in Hg-, carbon (C)-, and nitrogen (N)-stable isotope compositions of Arctic marine food webs. Hg-stable isotope ratios were measured in liver samples of 55 beluga whales (Delphinapterus leucas) and 15 polar bears (Ursus maritimus) collected since 1990. Large variations in δ202Hg (≈2.1‰) and Δ199Hg (≈1.7‰) are observed between species and within species stocks covering the Gulf of Alaska-Bering Sea-Arctic Ocean regions. Polar bears, mainly feeding on ringed seal (δ15N shift of 4.2‰), show identical liver Δ199Hg of 0.5‰, confirming the absence of metabolic mass-independent fractionation, and 0.33 ± 0.11‰ enrichment in heavy Hg isotopes. Beluga whale liver total Hg concentrations increase with age, reflecting lifetime bioaccumulation, while Hg speciation shifts to inorganic Hg with age as a result of hepatic methyl-Hg breakdown. Δ200Hg variations in biota show a small, 0.1‰ decrease from North Pacific Ocean to Arctic Ocean habitats, suggesting atmospheric Hg deposition to be important in the Pacific and terrestrial Hg inputs to dominate in the Arctic Ocean. Similar to seabird eggs, a consistent south to north gradient in Δ199Hg baseline is seen in mammal liver tissues, confirming sea ice cover as a control factor on marine Hg photoreduction and Δ199Hg. Arctic Ocean beluga whales have near zero Δ199Hg, indicating that terrestrial Hg and in-situ-produced methyl-Hg are not measurably photoreduced in the Arctic Ocean before entering the marine food web Article in Journal/Newspaper Arctic Arctic Ocean Beluga Beluga whale Beluga* Bering Sea Delphinapterus leucas ringed seal Sea ice Ursus maritimus Alaska Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Arctic Arctic Ocean Bering Sea Gulf of Alaska Pacific ACS Earth and Space Chemistry 2 5 479 490 |