Research

What we do

Chemical pollution is a major global threat to human, wildlife, and environmental health. Anthropogenic chemicals are one of the five main drivers of global biodiversity loss and have the potential to alter vital Earth system processes necessary for human life. Investigating chemical pollution of the environment is a gargantuan task given the >350,000 chemicals currently in use or registered for production globally and the addition of thousands of new chemicals each year. Regulation of chemicals is typically achieved by screening against a set of priority criteria based on PBLT properties: Persistence (does it break down?), Bioaccumulation (does it accumulate in wildlife?), Long-range transport (does it travel away from source regions?) and Toxicity (does it negatively impact wildlife?). Standard or traditional approaches in toxicology are based on live animal experiments, which come with obvious logistical challenges and ethical concerns. Furthermore, the time and monetary constraints of animal tests place limits on the number of chemicals that can be tested in a year, making it impossible to keep up to new chemical developments. To address these major challenges in ecotoxicology, we are increasingly turning to 21st Century approaches including in vitro (cell-based laboratory experiments) and in silico (computer-based experiments).

In the ecotoxicology and wildlife stress lab, we are interested in how ecological and anthropogenic factors influence how chemical pollutants move in the environment, accumulate in organisms, and their potential impacts on the physiology, health, and fitness of wildlife populations. One of the overarching practical goals of our work is to improve chemical management and wildlife risk assessment and to promote improved environmental health. To do this, we develop projects to assess the PBLT properties of legacy and new emerging chemicals. Our research focuses largely on the Arctic and high trophic feeding marine predators like polar bears, seals, and toothed whales that accumulate very high levels of chemicals in their body.

A wide variety of research tools and approaches are used to tackle our research questions, including in vitro experiments and molecular biomarkers (e.g., transcriptomics), ecological studies with wildlife, and ecological models of animal energetics, chemical accumulation and effects, and population dynamics. The lab is always growing and evolving, but our research falls broadly into the following major themes:

1. Wildlife ecology and toxicology: marine and terrestrial mammals are chronically exposed to multiple stressors that cumulatively impact the health and fitness of individuals and populations. We study how individual and multiple stressors impact wildlife across biological scales, from the molecular to population levels. Our big questions remain if and how impacts across scales are linked and can molecular biomarkers be used to assess ecologically relevant conservation questions? Here we will use a mixture of sampling and analytical approaches in wildlife, including chemical tissue residues, cell culture, immunotoxicology, transcriptomics, and dietary tracers to study the processes influencing exposure and effects of chemical pollution and other stressors like climate change. Sampling of chronological inert tissue like teeth, claws, tusk, hair and whiskers also offers exciting opportunities to explore interactions between stressors and animal ecology.

Photo credits: J. Desforges (seal, muskos), R. Dietz (tusk), P. Outridge (skull).

Photo credits: J. Desforges.

2. In vitro toxicology: Addressing the huge challenge of toxicity testing in the modern world containing hundreds of thousands of chemicals requires rapid, inexpensive, and animal-free methods. One approach is to rely on laboratory and cell-based assays to screen for PBLT properties of priority chemicals. Research in my lab focuses on developing and applying in vitro exposure and effects experiments to determine if and how chemicals accumulate and exert adverse effects, i.e. toxicokinetics and toxicodynamics. Here we explore both commercial cell lines and primary cells collected from wild animals. Assays include things like functional immunity and neurotoxicity. Another important question for us is how can use in vitro toxicity data outside of the lab? Here we combine experiments and modelling to explore in vitro to in vivo extrapolation.

3. Ecological and energy budget modelling: Conservation of biodiversity requires understanding of how individuals and populations interact with and respond to changes in their environment. Environmental conditions mediate demographic rates like survival, growth, and reproduction, and species life history strategies further mediate types of population responses. Energy has been put forward as a common currency to link environmental conditions to animal metabolic processes and fitness, which then ultimately determine population dynamics. Research in my lab focuses on the use of energetic modelling, specifically dynamic energy budget (DEB) Theory models, to link animals to their environment and predict how individuals and populations respond to natural and anthropogenic stressors like chemical pollution, climate change, and habitat loss/degradation. We use models to integrate information across scientific fields (molecular biology, movement ecology, ecophysiology, population biology, etc.) to answer questions about stress ecology in fish and wildlife.

Check out the People and Publication pages for more information about specific projects!