Our research approach is multidisciplinary, combining analytical isotope geochemistry, quantitative modeling, and ecological fieldwork. Some big questions that we are interested in are as follows.
1. What are the sources and exposure pathways of essential and deleterious chemicals found in wildlife and humans?
2. How do living organisms metabolize toxicants? Does the toxicokinetic mechanism vary across species including humans?
3. How does climate change drive ecological changes in marine ecosystems (e.g., food web structure and dynamics, migration timing, etc.)?
4. How do climate and ecological changes influence the exposures of wildlife and humans to contaminants and nutrients?
1. Global flows of methylmercury and fatty acids from fisheries harvests.
Collaborators: Colin Thackray & Elsie Sunderland (Harvard U), Vicky Lam & William Cheung (U of British Columbia).
This work links previously modeled Hg deposition into the ocean and seawater reservoirs of Hg species to MeHg flows associated with harvests of commercially important fish stocks. In addition, we simulate essential fatty acid flows from fish in the global oceans to humans for evaluating the risks and benefits of seafood consumption.
2. Deciphering changes in foraging habitats of beluga using lead isotopes.
Collaborators: Lisa Loseto (Canada Fisheries and Oceans), Dominique Weis (U of British Columbia), Craig Kastelle & Thomas Helser (NOAA).
We are developing geochemical tools (e.g., lead isotopes) to assess if the diet and habitat use patterns of Beaufort Sea beluga have changed in the past decade, potentially as a response to rapid climate change in the Arctic.
3.Modeling influences of environmental change on levels and trends of methylmercury in the Beaufort beluga food web.
Collaborators: Amanda Giang (U of British Columbia), Lisa Loseto (Canada Fisheries and Oceans), Carie Hoover (Dalhousie U), William Cheung (U. of British Columbia), Eva Kruemmel & Michale Scheer (ScienTissiME), Ruth Goldstein (UC Irvine).
Mercury can pose risks for marine ecosystem health in the Canadian Arctic. Rapid changes in Arctic climate may have affected mercury transport and bioaccumulation in Arctic species many different ways, and the causes of observed historical trends in beluga mercury are still unclear. The goals of this project are to use models to: (1) better understand how climate, ecological, and human influences have interacted to drive historical trends in Beaufort beluga mercury concentrations; (2) explore how mercury concentrations may respond to future climate change and mercury emissions
Image credit: Steve Snodgrass via Wikimedia Commons