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Jung S, Besnard L, Li ML, R Reinfelder J, Kim E, Kwon SY, Kim JH. Interspecific Variations in the Internal Mercury Isotope Dynamics of Antarctic Penguins: Implications for Biomonitoring. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:6349-6358. [PMID: 38531013 DOI: 10.1021/acs.est.3c09452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Mercury (Hg) biomonitoring requires a precise understanding of the internal processes contributing to disparities between the Hg sources in the environment and the Hg measured in the biota. In this study, we investigated the use of Hg stable isotopes to trace Hg accumulation in Adélie and emperor penguin chicks from four breeding colonies in Antarctica. Interspecific variation of Δ199Hg in penguin chicks reflects the distinct foraging habitats and Hg exposures in adults. Chicks at breeding sites where adult penguins predominantly consumed mesopelagic prey showed relatively lower Δ199Hg values than chicks that were primarily fed epipelagic krill. Substantial δ202Hg variations in chick tissues were observed in both species (Adélie: -0.11 to 1.13‰, emperor: -0.27 to 1.15‰), whereas only emperor penguins exhibited the lowest δ202Hg in the liver and the highest in the feathers. Our results indicate that tissue-specific δ202Hg variations and their positive correlations with % MeHg resulted from MeHg demethylation in the liver and kidneys of emperor penguin chicks, whereas Adélie penguin chicks showed different internal responses depending on their exposure to dietary MeHg. This study highlights the importance of considering intra- and interspecific variations in adult foraging ecology and MeHg demethylation when selecting penguin chicks for Hg biomonitoring.
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Affiliation(s)
- Saebom Jung
- Division of Environmental Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, South Korea
| | - Lucien Besnard
- Division of Environmental Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, South Korea
| | - Mi-Ling Li
- School of Marine Science and Policy, University of Delaware, Newark, Delaware 19716, United States
| | - John R Reinfelder
- Department of Environmental Sciences, Rutgers University, New Brunswick, New Jersey 08901, United States
| | - Eunhee Kim
- Citizens' Institute for Environmental Studies (CIES), Seoul 03039, South Korea
| | - Sae Yun Kwon
- Division of Environmental Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, South Korea
- Institute for Convergence Research and Education in Advanced Technology, Yonsei University, 85 Songdogwahak-ro, Incheon 21983, South Korea
| | - Jeong-Hoon Kim
- Korea Polar Research Institute (KOPRI), 26 Songdomirae-ro, Incheon 21990, South Korea
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Maccapan D, Careddu G, Calizza E, Sporta Caputi S, Rossi L, Costantini ML. Effects of Sea-Ice Persistence on the Diet of Adélie Penguin ( Pygoscelis adeliae) Chicks and the Trophic Differences between Chicks and Adults in the Ross Sea, Antarctica. BIOLOGY 2023; 12:biology12050708. [PMID: 37237522 DOI: 10.3390/biology12050708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/24/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023]
Abstract
In Antarctica, prey availability for the mesopredator Adélie penguin, Pygoscelis adeliae, depends on sea-ice dynamics. By affecting cycles of sea-ice formation and melt, climate change could thus affect penguin diet and recruitment. In the light of climate change, this raises concerns about the fate of this dominant endemic species, which plays a key role in the Antarctic food web. However, few quantitative studies measuring the effects of sea-ice persistence on the diet of penguin chicks have yet been conducted. The purpose of this study was to fill this gap by comparing penguin diets across four penguin colonies in the Ross Sea and evaluating latitudinal and interannual variation linked to different sea-ice persistence. Diet was evaluated by analysing the δ13C and δ15N values of penguin guano, and sea-ice persistence by means of satellite images. Isotopic values indicate that penguins consumed more krill in colonies with longer sea-ice persistence. In these colonies, the δ13C values of chicks were lower and closer to the pelagic chain than those of adults, suggesting that the latter apparently catch prey inshore for self-feeding and offshore for their chicks. The results indicate that sea-ice persistence is among the principal factors that influence the spatiotemporal variability of the penguins' diet.
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Affiliation(s)
- Deborah Maccapan
- Department of Environmental Biology, Sapienza University of Rome, Via dei Sardi 70, 00185 Rome, Italy
| | - Giulio Careddu
- Department of Environmental Biology, Sapienza University of Rome, Via dei Sardi 70, 00185 Rome, Italy
- CoNISMa, National Inter-University Consortium for Marine Sciences, Piazzale Flaminio 9, 00196 Rome, Italy
| | - Edoardo Calizza
- Department of Environmental Biology, Sapienza University of Rome, Via dei Sardi 70, 00185 Rome, Italy
- CoNISMa, National Inter-University Consortium for Marine Sciences, Piazzale Flaminio 9, 00196 Rome, Italy
| | - Simona Sporta Caputi
- Department of Environmental Biology, Sapienza University of Rome, Via dei Sardi 70, 00185 Rome, Italy
- CoNISMa, National Inter-University Consortium for Marine Sciences, Piazzale Flaminio 9, 00196 Rome, Italy
| | - Loreto Rossi
- Department of Environmental Biology, Sapienza University of Rome, Via dei Sardi 70, 00185 Rome, Italy
- CoNISMa, National Inter-University Consortium for Marine Sciences, Piazzale Flaminio 9, 00196 Rome, Italy
| | - Maria Letizia Costantini
- Department of Environmental Biology, Sapienza University of Rome, Via dei Sardi 70, 00185 Rome, Italy
- CoNISMa, National Inter-University Consortium for Marine Sciences, Piazzale Flaminio 9, 00196 Rome, Italy
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