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. Assessing the transport, transformation, and fate of PFAS across the land-sea transition.
Collaborators: Holly Michael (U of Delaware), Andrea Tokranov (USGS), Michelle Lorah (USGS), Emily Majcher (USGS).
We conduct a field-based research project to characterize the distribution, transport, fate, and potential remediation mechanisms from upland to coastal environments, specifically,
in two Delaware watersheds with contrasting PFAS point sources (wastewater treatment plant vs. air force base) and land uses (agriculture vs. urban).
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).
Mercury can pose risks to marine ecosystem health in the Canadian Arctic. Rapid changes in Arctic climate may have affected mercury transport and bioaccumulation in Arctic species in 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 better understand how climate, ecological, and human influences have interacted to drive historical trends in Beaufort beluga mercury concentrations.
Shannon Jones (left) and Tim Smoot (right) were sampling bivalves in Inland Bay, Delaware.
From left to right: Ashley Pavia, Shannon Jones, and Mi-Ling Li conducted fieldwork in St. Jones Reserve, a saltmarsh in the Delaware coast.