A 1500-year record of mercury isotopes in seal feces documents sea ice changes in the Antarctic
Abstract Temporal and spatial variations in sea ice coverage at high Northern Hemisphere latitudes have been shown to affect the photodegradation of methylmercury in seawater and the mercury isotope signatures in biological samples, suggesting the potential of mercury isotopes to reconstruct sea ice...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-07-01
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| Series: | Communications Earth & Environment |
| Online Access: | https://doi.org/10.1038/s43247-023-00921-3 |
| _version_ | 1797778717184884736 |
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| author | Hongwei Liu Wang Zheng Bridget A. Bergquist Yuesong Gao Fange Yue Lianjiao Yang Liguang Sun Zhouqing Xie |
| author_facet | Hongwei Liu Wang Zheng Bridget A. Bergquist Yuesong Gao Fange Yue Lianjiao Yang Liguang Sun Zhouqing Xie |
| author_sort | Hongwei Liu |
| collection | DOAJ |
| description | Abstract Temporal and spatial variations in sea ice coverage at high Northern Hemisphere latitudes have been shown to affect the photodegradation of methylmercury in seawater and the mercury isotope signatures in biological samples, suggesting the potential of mercury isotopes to reconstruct sea ice variability. Here we study the mercury isotopic composition of a 1500-year sediment profile strongly affected by seal activities on the Fildes Peninsula, King George Island, Antarctic Peninsula. The mass independent isotope fractionation of mercury (represented by Δ199Hg) in sediments dominated by seal feces input reflects the Δ199Hg of marine methylmercury before entering the food web, documenting the changes in the degree of photodemethylation. We found much higher Δ199Hg in sediments deposited during a warm period (~700-1000 years ago), suggesting that reduced sea ice promoted greater photodemethylation. Thus, this study demonstrates the modulation of methylmercury photodegradation by sea ice in the Antarctic, and that mercury isotopes can record historical sea ice changes. |
| first_indexed | 2024-03-12T23:20:30Z |
| format | Article |
| id | doaj.art-a4a1d348b76b47abb1c1ef5428d41510 |
| institution | Directory Open Access Journal |
| issn | 2662-4435 |
| language | English |
| last_indexed | 2024-03-12T23:20:30Z |
| publishDate | 2023-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Communications Earth & Environment |
| spelling | doaj.art-a4a1d348b76b47abb1c1ef5428d415102023-07-16T11:29:08ZengNature PortfolioCommunications Earth & Environment2662-44352023-07-014111010.1038/s43247-023-00921-3A 1500-year record of mercury isotopes in seal feces documents sea ice changes in the AntarcticHongwei Liu0Wang Zheng1Bridget A. Bergquist2Yuesong Gao3Fange Yue4Lianjiao Yang5Liguang Sun6Zhouqing Xie7Department of Environmental Science and Engineering, Anhui Key Laboratory of Polar Environment and Global Change, University of Science and Technology of ChinaInstitute of Surface-Earth System Science, School of Earth System Science, Tianjin UniversityDepartment of Earth Sciences, University of TorontoDepartment of Environmental Science and Engineering, Anhui Key Laboratory of Polar Environment and Global Change, University of Science and Technology of ChinaDepartment of Environmental Science and Engineering, Anhui Key Laboratory of Polar Environment and Global Change, University of Science and Technology of ChinaDepartment of Environmental Science and Engineering, Anhui Key Laboratory of Polar Environment and Global Change, University of Science and Technology of ChinaDepartment of Environmental Science and Engineering, Anhui Key Laboratory of Polar Environment and Global Change, University of Science and Technology of ChinaDepartment of Environmental Science and Engineering, Anhui Key Laboratory of Polar Environment and Global Change, University of Science and Technology of ChinaAbstract Temporal and spatial variations in sea ice coverage at high Northern Hemisphere latitudes have been shown to affect the photodegradation of methylmercury in seawater and the mercury isotope signatures in biological samples, suggesting the potential of mercury isotopes to reconstruct sea ice variability. Here we study the mercury isotopic composition of a 1500-year sediment profile strongly affected by seal activities on the Fildes Peninsula, King George Island, Antarctic Peninsula. The mass independent isotope fractionation of mercury (represented by Δ199Hg) in sediments dominated by seal feces input reflects the Δ199Hg of marine methylmercury before entering the food web, documenting the changes in the degree of photodemethylation. We found much higher Δ199Hg in sediments deposited during a warm period (~700-1000 years ago), suggesting that reduced sea ice promoted greater photodemethylation. Thus, this study demonstrates the modulation of methylmercury photodegradation by sea ice in the Antarctic, and that mercury isotopes can record historical sea ice changes.https://doi.org/10.1038/s43247-023-00921-3 |
| spellingShingle | Hongwei Liu Wang Zheng Bridget A. Bergquist Yuesong Gao Fange Yue Lianjiao Yang Liguang Sun Zhouqing Xie A 1500-year record of mercury isotopes in seal feces documents sea ice changes in the Antarctic Communications Earth & Environment |
| title | A 1500-year record of mercury isotopes in seal feces documents sea ice changes in the Antarctic |
| title_full | A 1500-year record of mercury isotopes in seal feces documents sea ice changes in the Antarctic |
| title_fullStr | A 1500-year record of mercury isotopes in seal feces documents sea ice changes in the Antarctic |
| title_full_unstemmed | A 1500-year record of mercury isotopes in seal feces documents sea ice changes in the Antarctic |
| title_short | A 1500-year record of mercury isotopes in seal feces documents sea ice changes in the Antarctic |
| title_sort | 1500 year record of mercury isotopes in seal feces documents sea ice changes in the antarctic |
| url | https://doi.org/10.1038/s43247-023-00921-3 |
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