Grant: Research Tools and Instruments

We are requesting funding to acquire three integral components of a system to quantify the size distribution and elemental composition of dissolved organic matter (DOM) in Arctic watersheds. Permafrost soils represent a large store of soil organic matter (SOM), which represents a potential source of atmospheric carbon (CO2 and CH4) that could result in a positive feedback on climate warming if this organic matter is subject to decomposition. Climate warming is increasing the physical disturbance and thaw of permafrost, which is exposing previously buried and frozen pools of SOM, leading to mobilization and transport of this source of organic carbon as DOM in Arctic watersheds. It is well known that the bioavailability and toxicity of many metals and contaminants, and the biodegradability of DOM is related to its size. Yet very little is known about the distribution, composition or reactivity of different size fractions of DOM across the Canadian Arctic. This lack of knowledge is a critical gap, that limits our ability to assess the potential impact of permafrost degradation on both the permafrost carbon feedback and contaminant transport in permafrost watersheds. We are requesting funding for a Shimadzu TOC-LPCH high sensitivity combustion system for the elemental analysis of total organic carbon (TOC) and total nitrogen (TN) in DOM, a Minimate tangential flow filtration (TFF) system for the size fractionation of DOM, and a Millipore Direct 8 water system to generate the ultrapure and carbon-free water that is required to conduct these analyses. This DOM size fractionation and elemental analysis system will enhance and further distinguish our research programs by providing the capacity to investigate the critical questions of how carbon biodegradability (and thus flux of C to the atmosphere) and contaminant bioavailability depend on the size fractions of organic matter in degrading permafrost environments. The equipment requested are essential analytical tools that will be subject to intensive year round usage in support of HQP training and research for our collaborative and integrated research programs at sites across the Canadian Arctic including: the Niaqunguk (Apex) watershed in Iqaluit, Bylot Island, Ward Hunt Island, and the Cape Bounty Arctic Watershed Observatory (CBAWO) on Melville Island. These research programs continue to generate highly cited and internationally recognized research that is contributing to modelling and predicting how Arctic watersheds will respond to, and feedback, on global climate change. All of the supported research projects will inform Arctic communities and decision makers of the sensitivity of ecosystems and water quality to climate related permafrost degradation, and will facilitate developing policy to better protect water resources as local climate changes.