Glacier recession is accelerating with alarming speed across the high latitude and elevation parts of our planet. Despite this urgency, we have only a limited understanding of the resident microbial life inhabiting these disappearing environments, and know even less about factors that might structure their communities. This is partially due to logistical challenges associated with accessing and sampling these large and diverse habitats, which is amplified due to their discontinuous geographical distributions. However, analysis of glacier-exported microbial cells in meltwater may reveal substantial information about the biogeography/dispersal of organisms, local biogeochemical processes, and dominant hydrological pathways, making comparisons between glaciers and regions more straightforward.
In a new paper published in Frontiers in Microbiology, led by Tyler and co-authored by Petra, Lukáš, Jakub, and Marek, microbial assemblages recovered from meltwater were used as proxies to study microbial communities inhabitating glacial habitats across the Arctic and sub-Arctic. In all, 24 glaciers from 6 major regions of the (sub-)Arctic were sampled. All glaciers were dominated by a handful of the same OTUs (shall we call them ‘microbial pigeons’?), though up to a third of the diversity was regionally unique; alpha diversity decreased with increasing latitude. Overall, assemblages were poorly explained by meltwater chemistry, despite containing metabolically-specific OTUs, suggesting the presence of localized microbial hotspots within the glacial environment. Overall, these results improve our understanding of microbial communities residing in glacial environments, and demonstrate that the study of microbial cells in meltwater may provide unique insights into these rapidly disappearing habitats.
Kohler TJ, Vinšová P, Falteisek L, Žárský JD, Yde JC, Hatton JE, Hawkings JR, Lamarche-Gagnon G, Hood E, Cameron KA, Stibal M (2020) Patterns in microbial assemblages exported from the meltwater of Arctic and sub-Arctic glaciers. Frontiers in Microbiology 11:669 doi: 10.3389/fmicb.2020.00669