Microbial Sentinels: Unveiling Arctic Lake Dynamics and Bioindicators of Climate Change

Lakes are often referred to as sentinels of climate change due to the shifting of physical, chemical, and biological responses occurring throughout their watersheds. Despite the fundamental role of microorganisms in the maintenance of a properly functioning lake ecosystem, microbial community structure and functioning remains poorly understood in the context of a changing Arctic. Additionally, the extent in which microorganisms act as sentinels of environmental changes remains largely overlooked. Here, we aimed to identify an Arctic lake core microbiome to assess its contribution to the overall gene pool; and further characterize select members of this intrinsic community by whole genome sequencing and carbon utilization measurements to assess their response to projected changes in the Arctic. To this end, the genetic content of clear-water Arctic lakes (Bylot Island, NU, Canada) and their surrounding areas (soils, inlets, etc.) was analyzed using high-throughput amplicon sequencing. These analyses revealed non-unique assemblages among the different lakes sampled, leading to the conclusion that innate lake characteristics drive microbial community partitioning in these environments. Moreover, the bacterial isolate studies disclosed specific substrates of interest for enhanced viability, and ongoing genomic analyses will further identify the main metabolic pathways used by these organisms. Since these lakes have low nutrient thresholds, environmental pressures attributed to climate change, such as brownification, can significantly alter internal biotic processes.

Primary Presenter: Emily Hallett, INRS (emily.hallett@inrs.ca)

Authors:

Emily Hallett, Institut national de la recherche scientifique  (Emily.Hallett@inrs.ca)

Thomas Deschênes, Institut national de la recherche scientifique  (Thomas.Deschenes@inrs.ca)

Maude Pomerleau, Institut national de la recherche scientifique  (maude.pomerleau@inrs.ca)

Jérôme Comte, Institut national de la recherche scientifique  (Jerome.Comte@inrs.ca)