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. Per- and polyfluoroalkyl substances (PFAS) contamination in marine biota of the Delaware Bay

Collaborators: Aaron Carlisle (U of Delaware). 

We are conducting a pilot project to assess the levels of PFASs in the marine biota from the Delaware Bay and Inland Bays and to investigate how PFAS compounds bioaccumulate in the Delaware marine food web.

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