Viruses in permafrost thaw ponds
Global warming due to climate change has caused an increase in the number of permafrost thaw ponds (thermokarst) in the northern polar region. Thermokarst ponds are supersaturated in carbon dioxide and methane and are thus important sources of greenhouse gases (GHG). Microbial activity is responsible for the majority of GHG production in these ponds. However, little is known about the sources of mortality in these communities. One potentially major top down factor is the viruses. Viruses play an essential ecological role in all aquatic ecosystems, yet these assemblages remain essentially uncharacterized in thermokarst ponds. Towards this end, we have focused on cultivation dependent and independent approaches to characterizing the viral community in this ecosystem of global importance.
Wild viruses in the High Arctic
The most abundant and diverse biological entities in aquatic environments are the protists, prokaryotes, and viruses that comprise the microbial community. Microbes play a critical role in the cycling of nutrients and energy, and therefore understanding the dynamics and interactions of this group is vital to understanding the ecology of aquatic ecosystems as a whole. An important, but relatively understudied, component of the microbial community is the viruses. As well as being the most abundant and diverse biological entities on Earth, viruses influence the community structure and evolution of their hosts, and ultimately the productivity of the entire biota. I am building my research program around two major themes, aquatic viral ecology in a changing climate and viral discovery. The Arctic is a model environment to pursue these two themes because the region is experiencing some of the most dramatic changes due to climate change on Earth and it harbors a wide diversity of aquatic habitats whose viral communities are largely uncharacterized. The long-term goal of my research is thus to gain a deeper understanding of the impact, diversity and dynamics of the in situ virus communities in diverse Arctic aquatic habitats, and how viral ecology is affected by the rapid and evolving changes in this ecosystem. Short-term: Towards this end, I propose to work in two locations in the Arctic that exemplify the dynamism of the region attributable to climate change to answer some important first order ecological questions about viruses. The first sampling site is an epishelf lake located on the northern coast of Ellesmere Island in the Canadian High Arctic and the second is Cambridge Bay, a location in the Canadian Arctic Archipelago on the southeastern coast of Victoria Island
Aerosols in the High Arctic
In collaboration with the Bioaerosols lab at Université Laval headed by Caroline Duchaine, we have started a project to characterize the diversity of microbes, and viruses in particular, in aerosols in the High Canadian Arctic. Led by Catherine Girard, a Sentinel North Postdoctoral Fellow, the overarching themes of this research are to characterize the diversity, functionality and activity of Arctic microbes in aerosols, how aerosols contribute to the hydrological cycles of representative aquatic systems, and elucidate the aerosol fingerprint of anthropogenically-influenced regions in the High North