Bacterial Dynamics in Supraglacial Habitats of the Greenland Ice Sheet

Authors Organisations
  • Miranda Jane Nicholes(Author)
    University of Bristol
  • Christopher James Williamson(Author)
    University of Bristol
  • Martyn Tranter(Author)
    University of Bristol
  • Alexandra Holland(Author)
    University of Bristol
  • Ewa Poniecka(Author)
    Prifysgol Caerdydd | Cardiff University
  • Marian Louise Yallop(Author)
    University of Bristol
  • Black and Bloom Team(Author)
  • Tristram Irvine-Fynn(Author)
  • Alexandre Anesio(Author)
    University of Bristol
    Aarhus University
Type Article
Original languageEnglish
Article number1366
Number of pages9
JournalFrontiers in Microbiology
Volume10
DOI
Publication statusPublished - 03 Jul 2019
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Abstract

Current research into bacterial dynamics on the Greenland Ice Sheet (GrIS) is biased toward cryoconite holes, despite this habitat covering less than 8% of the ablation (melt) zone surface. In contrast, the expansive surface ice, which supports wide-spread Streptophyte micro-algal blooms thought to enhance surface melt, has been relatively neglected. This study aims to understand variability in bacterial abundance and production across an ablation season on the GrIS, in relation to micro-algal bloom dynamics. Bacterial abundance reached 3.3 ± 0.3 × 105 cells ml−1 in surface ice and was significantly linearly related to algal abundances during the middle and late ablation periods (R2 = 0.62, p < 0.05; R2 = 0.78, p < 0.001). Bacterial production (BP) of 0.03–0.6 μg C L−1 h−1 was observed in surface ice and increased in concert with glacier algal abundances, indicating that heterotrophic bacteria consume algal-derived dissolved organic carbon. However, BP remained at least 28 times lower than net primary production, indicating inefficient carbon cycling by heterotrophic bacteria and net accumulation of carbon in surface ice throughout the ablation season. Across the supraglacial environment, cryoconite sediment BP was at least four times greater than surface ice, confirming that cryoconite holes are the true “hot spots” of heterotrophic bacterial activity.