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

PLoS One. 2013 Nov 25;8(11):e79972. doi: 10.1371/journal.pone.0079972. eCollection 2013.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arctic Regions
  • Environmental Monitoring*
  • Gene Dosage
  • Hydrogen-Ion Concentration
  • Mercury / analysis*
  • Mercury / chemistry
  • Microbial Interactions
  • Nitrogen / analysis
  • Nitrogen / chemistry
  • Nitrogen / metabolism
  • Phylogeny
  • RNA, Ribosomal, 16S / chemistry
  • RNA, Ribosomal, 16S / genetics
  • Snow / chemistry*
  • Snow / microbiology
  • Sulfur / analysis
  • Sulfur / chemistry
  • Sulfur / metabolism
  • Water Microbiology

Substances

  • RNA, Ribosomal, 16S
  • Sulfur
  • Mercury
  • Nitrogen

Grants and funding

The authors would like to thank the Institut Polar Emile Victor (CHIMERPOL 399) for financing the field campaign. They also thank Alan Le Tressoler, Nicolas Soumis and Nicolas Marusczak for their invaluable assistance in the field, and M. De Angelis for analytical support. This research was supported by grants from EC2CO (INSU/CNRS) and CL acknowledges the FQRNT (Le Fonds Québécois de la Recherche sur la Nature et les Technologies) for a PhD research fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.