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Microbial mercury methylation in Antarctic sea ice


Atmospheric deposition of mercury onto sea ice and circumpolar sea water provides mercury for microbial methylation, and contributes to the bioaccumulation of the potent neurotoxin methylmercury in the marine food web. Little is known about the abiotic and biotic controls on microbial mercury methylation in polar marine systems. However, mercury methylation is known to occur alongside photochemical and microbial mercury reduction and subsequent volatilization. Here, we combine mercury speciation measurements of total and methylated mercury with metagenomic analysis of whole-community microbial DNA from Antarctic snow, brine, sea ice and sea water to elucidate potential microbially mediated mercury methylation and volatilization pathways in polar marine environments. Our results identify the marine microaerophilic bacterium Nitrospina as a potential mercury methylator within sea ice. Anaerobic bacteria known to methylate mercury were notably absent from sea-ice metagenomes. We propose that Antarctic sea ice can harbour a microbial source of methylmercury in the Southern Ocean.

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Figure 1: Sea-ice and sea-water mercury and chlorophyll concentrations.
Figure 2: Fisher's exact test of taxonomic profiles for bulk sea-ice and brine metagenomes.
Figure 3: Maximum likelihood tree of HgcA-like sequences retrieved from polar and marine metagenomes and sequenced PCR products from this study (blue text).
Figure 4: Structural model of the Nitrospina HgcA-like protein complexed with cobalamin.


  1. 1

    Cossa, D. et al. Mercury in the southern ocean. Geochim. Cosmochim. Acta 75, 4037–4052 (2011).

    CAS  Google Scholar 

  2. 2

    Bargagli, R. Environmental contamination in Antarctic ecosystems. Sci. Total Environ. 400, 212–226 (2008).

    CAS  PubMed  Google Scholar 

  3. 3

    Arrigo, K. R. & Thomas, D. N. Large scale importance of sea ice biology in the southern ocean. Antarct. Sci. 16, 471–486 (2004).

    Google Scholar 

  4. 4

    Bowman, J. S., Berthiaume, C. T., Armbrust, E. & Deming, J. W. The genetic potential for key biogeochemical processes in Arctic frost flowers and young sea ice revealed by metagenomic analysis. FEMS Microbiol. Ecol. 89, 376–387 (2014).

    CAS  PubMed  Google Scholar 

  5. 5

    Møller, A. K. et al. Diversity and characterization of mercury-resistant bacteria in snow, freshwater and sea-ice brine from the High Arctic. FEMS Microbiol. Ecol. 75, 390–401 (2011).

    PubMed  Google Scholar 

  6. 6

    Møller, A. K. et al. Mercuric reductase genes (merA) and mercury resistance plasmids in High Arctic snow, freshwater and sea-ice brine. FEMS Microbiol. Ecol. 87, 52–63 (2014).

    PubMed  Google Scholar 

  7. 7

    Poulain, A. J. et al. Potential for mercury reduction by microbes in the high arctic. Appl. Environ. Microbiol. 73, 2230–2238 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  8. 8

    Parks, J. M. et al. The genetic basis for bacterial mercury methylation. Science 339, 1332–1335 (2013).

    CAS  PubMed  Google Scholar 

  9. 9

    Gilmour, C. C. et al. Mercury methylation by novel microorganisms from new environments. Environ. Sci. Technol. 47, 11810–11820 (2013).

    CAS  PubMed  Google Scholar 

  10. 10

    Heimbürger, L.-E. et al. Shallow methylmercury production in the marginal sea ice zone of the central Arctic Ocean. Sci. Rep. 5, 10318 (2015).

    Google Scholar 

  11. 11

    Lehnherr, I., St. Louis, V. L., Hintelmann, H. & Kirk, J. L. Methylation of inorganic mercury in polar marine waters. Nature Geosci. 4, 298–302 (2011).

    CAS  Google Scholar 

  12. 12

    Schartup, A. T. et al. Freshwater discharges drive high levels of methylmercury in Arctic marine biota. Proc. Natl Acad. Sci. USA 112, 11789–11794 (2015).

    CAS  PubMed  Google Scholar 

  13. 13

    Podar, M. et al. Global prevalence and distribution of genes and microorganisms involved in mercury methylation. Sci. Adv. 1, e1500675 (2015).

    PubMed  PubMed Central  Google Scholar 

  14. 14

    Humphries, R. et al. Boundary layer new particle formation over East Antarctic sea ice—possible Hg driven nucleation? Atmos. Chem. Phys. 15, 13339–13364 (2015).

    CAS  Google Scholar 

  15. 15

    Mason, R. P. et al. Mercury biogeochemical cycling in the ocean and policy implications. Environ. Res. 119, 101–117 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  16. 16

    Beattie, S. A. et al. Total and methylated mercury in arctic multiyear sea ice. Environ. Sci. Technol. 48, 5575–5582 (2014).

    CAS  PubMed  Google Scholar 

  17. 17

    Dommergue, A. et al. Overview of mercury measurements in the Antarctic troposphere. Atmos. Chem. Phys. 10, 3309–3319 (2010).

    CAS  Google Scholar 

  18. 18

    Ebinghaus, R. et al. Antarctic springtime depletion of atmospheric mercury. Environ. Sci. Technol. 36, 1238–1244 (2002).

    CAS  PubMed  Google Scholar 

  19. 19

    Andersson, M., Sommar, J., Gårdfeldt, K. & Lindqvist, O. Enhanced concentrations of dissolved gaseous mercury in the surface waters of the Arctic Ocean. Marine Chem. 110, 190–194 (2008).

    CAS  Google Scholar 

  20. 20

    Whalin, L., Kim, E.-H. & Mason, R. Factors influencing the oxidation, reduction, methylation and demethylation of mercury species in coastal waters. Marine Chem. 107, 278–294 (2007).

    CAS  Google Scholar 

  21. 21

    Chaulk, A., Stern, G. A., Armstrong, D., Barber, D. G. & Wang, F. Mercury distribution and transport across the ocean-sea ice-atmosphere interface in the Arctic Ocean. Environ. Sci. Technol. 45, 1866–1872 (2011).

    CAS  PubMed  Google Scholar 

  22. 22

    Constant, P., Poissant, L., Villemur, R., Yumvihoze, E. & Lean, D. Fate of inorganic mercury and methyl mercury within the snow cover in the low Arctic tundra on the shore of Hudson Bay (Québec, Canada). J. Geophys. Res. 112, D08309 (2007).

    Google Scholar 

  23. 23

    St Louis, V. L. et al. Methylated mercury species in Canadian high Arctic marine surface waters and snowpacks. Environ. Sci. Technol. 41, 6433–6441 (2007).

    CAS  PubMed  Google Scholar 

  24. 24

    Larose, C. et al. Springtime changes in snow chemistry lead to new insights into mercury methylation in the Arctic. Geochim. Cosmochim. Acta 74, 6263–6275 (2010).

    CAS  Google Scholar 

  25. 25

    Soerensen, A. L. et al. A mass budget for mercury and methylmercury in the Arctic Ocean. Global Biogeochem. Cycles 30, 560–575 (2016).

    CAS  Google Scholar 

  26. 26

    Hamelin, S., Amyot, M., Barkay, T., Wang, Y. & Planas, D. Methanogens: principal methylators of mercury in lake periphyton. Environ. Sci. Technol. 45, 7693–7700 (2011).

    CAS  PubMed  Google Scholar 

  27. 27

    Desrosiers, M., Planas, D. & Mucci, A. Mercury methylation in the epilithon of boreal shield aquatic ecosystems. Environ. Sci. Technol. 40, 1540–1546 (2006).

    CAS  PubMed  Google Scholar 

  28. 28

    Leclerc, M., Planas, D. & Amyot, M. Relationship between extracellular and low-molecular-weight thiols and mercury species in natural lake periphytic biofilms. Environ. Sci. Technol. 49, 7709–7716 (2015).

    CAS  PubMed  Google Scholar 

  29. 29

    Yin, Y., Li, Y., Tai, C., Cai, Y. & Jiang, G. Fumigant methyl iodide can methylate inorganic mercury species in natural waters. Nature Commun. 5, 4633 (2014).

    Google Scholar 

  30. 30

    Manley, S. L. & de la Cuesta, J. L. Methyl iodide production from marine phytoplankton cultures. Limnol. Oceanogr. 42, 142–147 (1997).

    CAS  Google Scholar 

  31. 31

    Celo, V., Lean, D. R. S. & Scott, S. L. Abiotic methylation of mercury in the aquatic environment. Sci. Total Environ. 368, 126–137 (2006).

    CAS  PubMed  Google Scholar 

  32. 32

    Grégoire, D. S. & Poulain, A. A little bit of light goes a long way: the role of phototrophs on mercury cycling. Metallomics 6, 396–407 (2014).

    PubMed  Google Scholar 

  33. 33

    Tynan, C. T. Ecological importance of the southern boundary of the Antarctic Circumpolar Current. Nature 392, 708–710 (1998).

    CAS  Google Scholar 

  34. 34

    Mason, R. & Fitzgerald, W. Alkylmercury species in the equatorial Pacific. Nature 347, 457–459 (1990).

    CAS  Google Scholar 

  35. 35

    Cossa, D., Averty, B. & Pirrone, N. The origin of methylmercury in open Mediterranean waters. Limnol. Oceanogr. 54, 837–844 (2009).

    CAS  Google Scholar 

  36. 36

    Sunderland, E. M., Krabbenhoft, D. P., Moreau, J. W., Strode, S. A. & Landing, W. M. Mercury sources, distribution, and bioavailability in the North Pacific Ocean: insights from data and models. Global Biogeochem. Cycles 23, GB2010 (2009).

  37. 37

    Bowman, K. L., Hammerschmidt, C. R., Lamborg, C. H. & Swarr, G. Mercury in the North Atlantic Ocean: the US GEOTRACES zonal and meridional sections. Deep-Sea Res. II 116, 251–261 (2015).

    CAS  Google Scholar 

  38. 38

    Bowman, J. P. et al. Diversity and association of psychrophilic bacteria in Antarctic sea ice. Appl. Environ. Microbiol. 63, 2068–3078 (1997).

    Google Scholar 

  39. 39

    Maccario, L., Vogel, T. M. & Larose, C. Potential drivers of microbial community structure and function in Arctic spring snow. Front. Microbiol. 5, 413 (2014).

    Google Scholar 

  40. 40

    Smith, S. D. et al. Site-directed mutagenesis of HgcA and HgcB reveals amino acid residues important for mercury methylation. Appl. Environ. Microbiol. 81, 3205–3217 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  41. 41

    Tringe, S. G. et al. Comparative metagenomics of microbial communities. Science 308, 554–557 (2005).

    CAS  PubMed  PubMed Central  Google Scholar 

  42. 42

    Zhou, J., Riccardi, D., Beste, A., Smith, J. C. & Parks, J. M. Mercury methylation by hgcA: theory supports carbanion transfer to Hg(ii). Inorg. Chem. 53, 772–777 (2013).

    PubMed  Google Scholar 

  43. 43

    Levipan, H. A., Molina, V. & Fernandez, C. Nitrospina-like bacteria are the main drivers of nitrite oxidation in the seasonal upwelling area of the Eastern South Pacific (Central Chile 36°S). Environ. Microbiol. Rep. 6, 565–573 (2014).

    CAS  PubMed  Google Scholar 

  44. 44

    Ngugi, D. K. et al. Diversification and niche adaptations of Nitrospina-like bacteria in the polyextreme interfaces of Red Sea brines. ISME J 10, 1383–1399 (2016).

    CAS  PubMed  Google Scholar 

  45. 45

    Barber, D. et al. Frost flowers on young Arctic sea ice: the climatic, chemical, and microbial significance of an emerging ice type. J. Geophys. Res. 119, 11593–11612 (2014).

    CAS  Google Scholar 

  46. 46

    Delmont, T. O., Hammar, K. M., Ducklow, H. W., Yager, P. L. & Post, A. F. Phaeocystis antarctica blooms strongly influence bacterial community structures in the Amundsen Sea polynya. Front. Microbiol. 5, 646 (2014).

  47. 47

    Boyd, E. S. & Barkay, T. The mercury resistance operon: from an origin in a geothermal environment to an efficient detoxification machine. Front. Microbiol. 3, 349 (2012).

    Google Scholar 

  48. 48

    Pitts, K. E. & Summers, A. O. The roles of thiols in the bacterial organomercurial lyase (MerB). Biochemistry 41, 10287–10296 (2002).

    CAS  PubMed  Google Scholar 

  49. 49

    Hamlett, N., Landale, E., Davis, B. & Summers, A. Roles of the Tn21 merT, merP, and merC gene products in mercury resistance and mercury binding. J. Bacteriol. 174, 6377–6385 (1992).

    CAS  PubMed  PubMed Central  Google Scholar 

  50. 50

    Gionfriddo, C. M., Tate, M., Krabbenhoft, D. P., Moreau, J. W. & Schofield, R. Total and Methyl- mercury Analysis of Sea Ice, Seawater, Snow, and Brine Samples Collected During the SIPEX II Voyage of the Aurora Australis (Australian Antarctic Data Centre, 2013, updated 2015).

    Google Scholar 

  51. 51

    Gionfriddo, C., Tate, M., Krabbenhoft, D., Moreau, J. W. & Schofield, R. Gaseous Elemental Mercury Measurements of Boundary Layer Air Made by a Tekran 2537 During the SIPEX II Voyage of the Aurora Australis, 2012 (Australian Antarctic Data Centre, 2013, updated 2015).

    Google Scholar 

  52. 52

    Chever, F., Schallenberg, C. & Bowie, A. R. Trace Metal Water Column Samples Collected on the SIPEX II Voyage of the Aurora Australis (Australian Antarctic Data Centre—CAASM Metadata, 2013, updated 2014).

    Google Scholar 

  53. 53

    Meiners, K., King, R., Reeve, J., Jordan, M. & Williams, J. Conductivity, Temperature and Depth (CTD) Data from the SIPEX II Voyage of the Aurora Australis (Australian Antarctic Data Centre—CAASM Metadata, 2013, updated 2014);

  54. 54

    Meiners, K., Westwood, K., Van Den Enden, D. & Ugalde, S. Sea Ice Main Biology Sampling Collected During the SIPEX II Voyage of the Aurora Australis, 2012 (Australian Antarctic Data Centre—CAASM Metadata (2013, updated 2014);

  55. 55

    Lannuzel, D. et al. Sea Ice Trace Metals Sampling During the SIPEX II Voyage of the Aurora Australis, 2012 (Australian Antarctic Data Centre—CAASM Metadata (2013, updated 2014);

  56. 56

    Olson, M. L. & DeWild, J. F. Techniques for the Collection and Species-Specific Analysis of Low Levels of Mercury in Water, Sediment, and Biota, Report No. 99–4018B (US Geological Survey, 1999).

  57. 57

    Hammerschmidt, C. R., Bowman, K. L., Tabatchnick, M. D. & Lamborg, C. H. Storage bottle material and cleaning for determination of total mercury in seawater. Limnol. Oceanogr. Methods 9, 426–431 (2011).

    CAS  Google Scholar 

  58. 58

    Miller, L. A. et al. Methods for biogeochemical studies of sea ice: the state of the art, caveats, and recommendations. Elementa: Sci. Anthropocene 3, 000038 (2015).

    Google Scholar 

  59. 59

    Lannuzel, D. et al. Iron biogeochemistry in Antarctic pack ice during SIPEX-2. Deep-Sea Res. II (2014).

  60. 60

    Roukaerts, A. et al. Sea ice algal primary production and nitrogen uptake rates off East Antarctica. Deep-Sea Res. II (2015).

  61. 61

    Boetius, A., Anesio, A. M., Deming, J. W., Mikucki, J. A. & Rapp, J. Z. Microbial ecology of the cryosphere: sea ice and glacial habitats. Nature Rev. Microbiol. 13, 677–690 (2015).

    CAS  Google Scholar 

  62. 62

    Deming, J. W. Psychrophiles and polar regions. Curr. Opin. Microbiol. 5, 301–309 (2002).

    CAS  PubMed  Google Scholar 

  63. 63

    Junge, K., Eicken, H. & Deming, J. W. Bacterial activity at −2 to −20 °C in Arctic wintertime sea ice. Appl. Environ. Microbiol. 70, 550–557 (2004).

    CAS  PubMed  PubMed Central  Google Scholar 

  64. 64

    Garrison, D. L. & Buck, K. R. Organism losses during ice melting: a serious bias in sea ice community studies. Polar Biol. 6, 237–239 (1986).

    Google Scholar 

  65. 65

    Mikkelsen, D. M. & Witkowski, A. Melting sea ice for taxonomic analysis: a comparison of four melting procedures. Polar Res. 29, 451–454 (2010).

    Google Scholar 

  66. 66

    Ewert, M., Carpenter, S., Colangelo-Lillis, J. & Deming, J. Bacterial and extracellular polysaccharide content of brine-wetted snow over Arctic winter first-year sea ice. J. Geophys. Res. 118, 726–735 (2013).

    CAS  Google Scholar 

  67. 67

    Meiners, K. M. et al. Physico-ecobiogeochemistry of East Antarctic pack ice during the winter–spring transition. Deep-Sea Res. II 58, 1172–1181 (2011).

    CAS  Google Scholar 

  68. 68

    Becquevort, S. et al. Biogeochemistry and microbial community composition in sea ice and underlying seawater off East Antarctica during early spring. Polar Biol. 32, 879–895 (2009).

    Google Scholar 

  69. 69

    Li, D., Liu, C.-M., Luo, R., Sadakane, K. & Lam, T.-W. MEGAHIT: an ultra-fast single-node solution for large and complex metagenomics assembly via succinct de Bruijn graph. Bioinformatics 31, 1674–1676 (2015).

    CAS  PubMed  Google Scholar 

  70. 70

    Meyer, F. et al. The metagenomics RAST server—a public resource for the automatic phylogenetic and functional analysis of metagenomes. BMC Bioinformatics 9, 386 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  71. 71

    Peng, Y., Leung, H. C., Yiu, S.-M. & Chin, F. Y. IDBA-UD: a de novo assembler for single-cell and metagenomic sequencing data with highly uneven depth. Bioinformatics 28, 1420–1428 (2012).

    CAS  Google Scholar 

  72. 72

    Altschul, S. F., Gish, W., Miller, W., Myers, E. W. & Lipman, D. J. Basic local alignment search tool. J. Mol. Biol. 215, 403–410 (1990).

    CAS  PubMed  PubMed Central  Google Scholar 

  73. 73

    Wilke, A. et al. The M5nr: a novel non-redundant database containing protein sequences and annotations from multiple sources and associated tools. BMC Bioinformatics 13, 141 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  74. 74

    Rice, P., Longden, I. & Bleasby, A. EMBOSS: the European molecular biology open software suite. Trends Genet. 16, 276–277 (2000).

    CAS  Google Scholar 

  75. 75

    Eddy, S. R. Accelerated profile HMM searches. PLoS Comput. Biol. 7, e1002195 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  76. 76

    Cavicchioli, R. Microbial ecology of Antarctic aquatic systems. Nature Rev. Microbiol. 13, 691–706 (2015).

    CAS  Google Scholar 

  77. 77

    Thompson, J. D., Gibson, T. & Higgins, D. G. Multiple sequence alignment using ClustalW and ClustalX. Curr. Protoc. Bioinformatics Ch. 2, Unit 2.3 (2002).

  78. 78

    Tamura, K., Stecher, G., Peterson, D., Filipski, A. & Kumar, S. MEGA6: molecular evolutionary genetics analysis version 6.0. Mol. Biol. Evol. 30, 2725–2729 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  79. 79

    Korbie, D. J. & Mattick, J. S. Touchdown PCR for increased specificity and sensitivity in PCR amplification. Nature Protoc. 3, 1452–1456 (2008).

    CAS  Google Scholar 

  80. 80

    Zemla, A. et al. AS2TS system for protein structure modeling and analysis. Nucleic Acids Res. 33, W111–W115 (2005).

    CAS  PubMed  PubMed Central  Google Scholar 

  81. 81

    Zemla, A. T., Lang, D. M., Kostova, T., Andino, R. & Zhou, C. L. E. StralSV: assessment of sequence variability within similar 3D structures and application to polio RNA-dependent RNA polymerase. BMC Bioinformatics 12, 226 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  82. 82

    Krivov, G. G., Shapovalov, M. V. & Dunbrack, R. L. Improved prediction of protein side-chain conformations with SCWRL4. Proteins Struct. Funct. Bioinformatics 77, 778–795 (2009).

    CAS  Google Scholar 

  83. 83

    Chen, V. B. et al. MolProbity: all-atom structure validation for macromolecular crystallography. Acta Crystallogr. D 66, 12–21 (2009).

    PubMed  Google Scholar 

  84. 84

    Pettersen, E. F. et al. UCSF Chimera—a visualization system for exploratory research and analysis. J. Comput. Chem. 25, 1605–1612 (2004).

    CAS  PubMed  PubMed Central  Google Scholar 

  85. 85

    Parks, D. H., Tyson, G. W., Hugenholtz, P. & Beiko, R. G. STAMP: statistical analysis of taxonomic and functional profiles. Bioinformatics 30, 3123–3124 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  86. 86

    Schlitzer, R. Ocean Data View (Alfred Wegener Institute for Polar and Marine Research, 2015);

  87. 87

    Kurtz, N. T. & Markus, T. Satellite observations of Antarctic sea ice thickness and volume. J. Geophys. Res. 117, C08025 (2012).

    Google Scholar 

  88. 88

    Markus, T. et al. Freeboard, snow depth, and sea ice roughness in East Antarctica from in-situ and multiple satellite data. Ann. Glaciol. 52, 242–248 (2011).

    Google Scholar 

  89. 89

    Cavalieri, D. J. et al. Deriving long-term time series of sea ice cover from satellite passive-microwave multisensor data sets. J. Geophys. Res. 104, 15803–15814 (1999).

    Google Scholar 

  90. 90

    Cavalieri, D. J., Parkinson, C. L., DiGirolamo, N. & Ivanoff, A. Intersensor calibration between F13 SSMI and F17 SSMIS for global sea ice data records. IEEE Geosci. Remote Sensing Lett. 9, 233–236 (2012).

    Google Scholar 

  91. 91

    Müller, S. et al. Selective incorporation of dissolved organic matter (DOM) during sea ice formation. Marine Chem. 155, 148–157 (2013).

    Google Scholar 

  92. 92

    Sierra, C., Ordóñez, C., Saavedra, A. & Gallego, J. Element enrichment factor calculation using grain-size distribution and functional data regression. Chemosphere 119, 1192–1199 (2015).

    CAS  PubMed  Google Scholar 

  93. 93

    Cox, G. F. N. & Weeks, W. F. Equations for determining the gas and brine volumes in sea-ice samples. J. Glaciol. 29, 306–316 (1983).

    Google Scholar 

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The authors acknowledge funding support from the Australian Antarctic Division (AAD4032, awarded to R.S., J.W.M., M.T.T. and D.P.K.) and The University of Melbourne Joyce Lambert Antarctic Research Seed Funding Grant (no. 501325, awarded to M.B.S., K.E.H. and J.W.M.). The authors thank K. Meiners for contributions to the sea ice chemistry data and shipboard logistical support as the Chief Scientist of SIPEX II; A. Klekociuk (Australian Antarctic Division, Co-Investigator on AAD4032) for shipboard logistical support; D. Lannuzel and A. Bowie (University of Tasmania) for making trace metal data available and for shipboard sampling and logistical support; K. Westwood at the Australian Antarctic Division for assistance in the biology laboratory and contributions to water chemistry data; and A. Martin, S. Ugalde, F. Chever, C. Schallenberg and J. Janssens (SIPEX II Science Party) for logistical assistance on the ice. The authors also thank J. Banfield and B. Thomas (University of California-Berkeley) for help with ggKbase. The authors thank J. Santillan and C. Gilmour (Smithsonian Environmental Research Center) for their constructive review that helped to improve this manuscript.

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C.M.G. and J.W.M. designed the project and wrote the manuscript with contributions from all co-authors. C.M.G. was the shipboard scientist on the Aurora Australis for SIPEX II, and J.W.M. and R.S. were the research co-supervisors. M.T.T. assisted C.M.G. with the installation of Hg analytical equipment, and C.M.G. performed the laboratory-based Hg analyses with assistance from M.T.T. and under the supervision of D.P.K. and J.W.M. C.M.G., R.R.W. and M.B.S. performed the metagenomic and bioinformatic analyses, supervised by K.E.H. and J.W.M. A.Z. and M.P.T. performed the protein analysis and structural modelling with inputs from C.M.G., J.W.M. and K.E.H.

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Correspondence to John W. Moreau.

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Gionfriddo, C., Tate, M., Wick, R. et al. Microbial mercury methylation in Antarctic sea ice. Nat Microbiol 1, 16127 (2016).

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