PLoS ONE (Jan 2013)

Interactions between snow chemistry, mercury inputs and microbial population dynamics in an Arctic snowpack.

  • Catherine Larose,
  • Emmanuel Prestat,
  • Sébastien Cecillon,
  • Sibel Berger,
  • Cédric Malandain,
  • Delina Lyon,
  • Christophe Ferrari,
  • Dominique Schneider,
  • Aurélien Dommergue,
  • Timothy M Vogel

DOI
https://doi.org/10.1371/journal.pone.0079972
Journal volume & issue
Vol. 8, no. 11
p. e79972

Abstract

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We investigated the interactions between snowpack chemistry, mercury (Hg) contamination and microbial community structure and function in Arctic snow. Snowpack chemistry (inorganic and organic ions) including mercury (Hg) speciation was studied in samples collected during a two-month field study in a high Arctic site, Svalbard, Norway (79 °N). Shifts in microbial community structure were determined by using a 16S rRNA gene phylogenetic microarray. We linked snowpack and meltwater chemistry to changes in microbial community structure by using co-inertia analyses (CIA) and explored changes in community function due to Hg contamination by q-PCR quantification of Hg-resistance genes in metagenomic samples. Based on the CIA, chemical and microbial data were linked (p = 0.006) with bioavailable Hg (BioHg) and methylmercury (MeHg) contributing significantly to the ordination of samples. Mercury was shown to influence community function with increases in merA gene copy numbers at low BioHg levels. Our results show that snowpacks can be considered as dynamic habitats with microbial and chemical components responding rapidly to environmental changes.