Current Research Projects

Can lake sediments be used to trace the occupation of ancient Arctic peoples?

Studying how arsenic and mercury affect ecosystems near Yellowknife gold mines

Contaminant and Nutrient Amplification by Migratory Animals (Biovectors)

   Industrial contaminants reaching the Arctic can have a significant impact on people and ecosystems. The prevailing view is that long range transport of semivolatile contaminants to the Arctic is primarily conducted by the physical system (e.g. winds, currents). Although this view may be correct in terms of bulk budgets and fluxes, it neglects the potential of animal behaviour to focus contaminants into foodwebs due to their behaviours and lifecycles. In particular, gregarious animals that biomagnify and bioaccumulate certain contaminants and then migrate and congregate can become the predominant pathway for contaminants in many circumstances following five major steps: emissions, loading, collection, transport, and deposition or transfer of contaminants to receptor sites. Anadromous fish, like sockeye salmon, colonial seabirds, and whales provide prominent examples for such behavior in the Arctic. Over the past ten years, we have been examining the potential for biovector transport in the Arctic to expose receptor ecosystems to pollutants.

Thaw slump Mackenzie Delta, NT (photo:A. Houben)

Impact of Thawing Permafrost on Biogeochemical Cycles

   We are assessing the impact of thawing permafrost on freshwaters on the Mackenzie Delta in the Northwest Territories, and in Old Crow Flats in the Yukon. By identifying lakes affected by recent permafrost thaw slumps with aerial photographs, and comparing lakes receiving large discharges from thawing permafrost with lakes where permafrost degradation is less apparent, we can determine the extent that melting permafrost affects water quality (organic contaminants, metals, nutrients). Using this information, we can develop methods to track permafrost degradation in lakes. By extracting lake sediment cores, we will apply these tools to reconstruct the history of permafrost degradation in lakes, and determine if chemical releases by permafrost thawing diminish over time. Finally, we will determine if contaminants released by degrading permafrost are accumulating in freshwater food webs that constitute an important part of traditional diet and lifestyle.

Impact of Climate Warming on the Biogeochemistry of Northern Environments

   Recent and dramatic climate changes in Arctic freshwaters are affecting the transport and fate of anthropogenic contaminants to aquatic systems, the two largest threats facing northern communities and ecosystems. This research will develop new tools to examine how the fate of anthropogenic contaminants is affected in Arctic regions under different climate change conditions. Due to the paucity of direct environmental monitoring in Arctic regions, this proposal will investigate how contaminant cycles in Arctic freshwater ecosystems are affected by climate change as recorded in sediment archives. We will combine established, state-of-the-art technologies in reconstructing climate from preserved sedimentary paleolimnological proxies, and concurrent records of contaminant deposition histories.

Pharmaceuticals and Personal Care Products in the Environment

   Endocrine disrupting chemicals (EDCs) are a class of chemicals that mimic the action of natural hormones in the environment and adversely affect the function of the endocrine system leading to alteration in growth, development, and reproduction in exposed animals. Steroidal estrogens, alkylphenols, certain pesticides, bisphenol A and synthetic musk fragrances are EDCs that are being detected in the effluent of wastewater treatment plants (WWTPs) as well as the receiving waters and sediments at very low concentrations but are sometimes present at biologically active concentrations. In male fish and frogs, the induction of vitellogenin (VTG), a precursor egg yolk protein synthesized typically in females by the action of their endogenous estrogen, and intersex are well recognized biological endpoints of estrogenic chemicals in the environment.