Northern aquatic microbiomes faced with rapid environmental change.

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Microorganisms are a diverse and important component of aquatic ecosystems. My research program investigates the biodiversity, metabolic versatility, and evolution of these important aquatic microbes using novel genomics-based molecular approaches. Aquatic ecosystems under investigation include northern oceans, estuaries, and most recently, seasonally ice-covered northern lakes. All these ecosystems are impacted by climate change and other anthropogenic perturbations to varying degrees. My research program is coordinated to provide insights into how microbial distributions and activities may be influenced by these environmental pressures and the long-term objective is to develop a predictive understanding of how microorganisms respond to environmental variability in aquatic ecosystems. Previously, we employed advanced genomics approaches to discover and describe important carbon, nitrogen, and sulfur cycling metabolic pathways in coastal and estuarine marine systems. Based on past successes, the research program is expanding to investigate microbes in the rapidly changing Arctic Ocean and seasonally ice-covered northern lakes. Specific objectives include: (1) to assess the interannual variability of microbial community structure and function in the rapidly changing AO, (2) to identify microbial taxa that are endemic to the AO and characterize their adaptive traits using comparative genomics, (3) to assess the variability of microbial community structure and function in northern lakes during ice-free and ice-covered periods of the year. Program objectives will be addressed by a research team that is integrated into large-scale collaborative studies on the influence of environmental change on aquatic ecosystems. We have access to a unique archive of microbial samples collected throughout the Arctic Ocean over the past 10 years as part of an ongoing oceanographic monitoring program. In addition, we have generated a multi-year archive of microbial samples collected throughout the ice-free and ice-covered periods from three lake observatories located in different regions of Quebec. Using a variety of cultivation-independent' molecular methods including metagenomics and in situ gene expression analysis, we will provide an unprecedented view of microbial distributions and activities in these changing northern ecosystems. Insights generated by the research program will be essential in the development of models that predict the relationships between microbial community structure and function and the physical and biogeochemical processes that are shifting as a result of climate change. This work will provide novel insight in the fields of microbial ecology and oceanography by revealing previously unrecognized patterns in microbial diversity and metabolism associated with changing conditions in the Canadian northern waters.