Dr. Jean-Pierre Desforges is an Assistant Professor in the department of Environmental Studies and Sciences at the University of Winnipeg. His research focuses on understanding the impacts of human activities on the environment and wildlife populations. With the continuing loss of sea ice due to climate change, Arctic species like the polar bear and ringed seal are under threat. Desforges and his team have developed an innovative approach to study the health of polar bear populations; a method that can provide valuable insights into their biology, ecology, and behaviour affected by long-term environmental change in the arctic.

On this episode the research question is: what can polar bear teeth tell us about the impacts of climate change?

KENT DAVIES: Polar bears, one of the most iconic species in the world. Polar bears are not only important because they help maintain the balance of the Arctic ecosystem, they also hold a deep cultural significance in many communities. Over the years they have become symbols of conservation in the face of unrelenting climate change. Because these apex predators rely on sea ice to hunt, their survival is directly tied to the health of the Arctic ecosystem.[i]

JEAN-PIERRE DESFORGES: Those warmer temperatures are melting ice and snow. We’re losing sea ice thickness, losing sea ice extent. So, the overall coverage in the Arctic Ocean. And that’s changing not only the habitat for species that live in the Arctic, right. So, we call them endemic species like polar bears, Arctic seals, narwhals. They’ve evolved millions of years to interact with that sea ice. They rely on it for many parts of their life and what we know is we’re losing that sea ice, right, year after year. We’re just losing way more than we ever have before. 

KENT DAVIES: That’s Dr. Jean-Pierre Desforges, an Assistant Professor in the department of Environmental Studies and Sciences at the University of Winnipeg. Desforges researches environmental toxicology and wildlife stress ecology, focusing on understanding the impacts of human activities on ecosystems. Desforges and his team is taking up a new approach to research the health of polar bear populations. A method that can provide valuable insights into a variety of aspects of their biology, ecology, and behavior affected by long-term environmental change in the arctic.

On this episode the research question is: what can polar bear teeth tell us about the impacts of climate change?

From the University of Winnipeg Oral History Centre, you’re listening to Research Question- amplifying the impact of discovery of the researchers of the University of Winnipeg.

KENT DAVIES: Dr. Jean-Pierre Desforges’ research sometimes involves experiencing close up encounters with wildlife in some of the world’s most remote locations.

JEAN-PIERRE DESFORGES: I’ve certainly been fortunate enough to see some pretty amazing animals that have always been on my kind of bucket list to see. Working in the North with fairly rare animals that are in remote areas. Every encounter I find, you know, pretty unique and special in that sense. We’ve encountered polar bears in the field, whether we’re specifically looking for bears for a sampling program, or we are there for something else. And you run into a couple bears, which is always, you know, scary and also exciting because that’s what you’re hoping is going to happen in a safe environment. I’ve gone to Northeast Greenland to sample narwhal in these amazing picturesque fjords where you have ice on both sides tall as skyscrapers, then a pod of narwhals come, you know, their tusks up above the water. So, feelings like that have been really, really amazing.

KENT DAVIES: Looking back, arctic field research wasn’t necessarily something that Desforges thought he would be doing as part of his job.

JEAN-PIERRE DESFORGES: So, I grew up in southwestern Ontario, home of Wayne Gretzky, Brantford, Ontario in a French community. My parents are both Franco-Ontarian, and I went to school French my whole life. They’re moved to Woodstock, another kind of very small town.

My family was never truly kind of an outdoor family. You know, like we might have gone camping here and there and, you know, gone on family road trips and seen some cool places. We did that quintessential trip to Banff. You go drive through the Rockies and I remember seeing grizzly bears on the side of the road and we saw lynx and we saw really cool wildlife. And that really had been the first kind of time that I think I was really exposed to that. So, I think that kind of piqued some interest, but I really think it kind of came later in life.

I went and did my undergraduate degree at the University of Ottawa. So, you know, moved away from home, started learning about environmental science. Expanding my horizons, trying to figure out what I wanted to do with my life. Not really knowing where I was going to go, but knowing I was interested in science. 

KENT DAVIES: At the University of Ottawa, Desforges came across a paper which piqued his interest towards a certain field of research.

JEAN-PIERRE DESFORGES: What really chose the field that I’m in now, so I’m an environmental toxicologist and study wildlife. I didn’t know that was a field. I didn’t know that existed. I didn’t know that was a thing you could do with your life until my third-year course called environmental toxicology, where you started learning about that, right? You started learning about pollution, some of the chemicals that humans are releasing in the environment, and how those get into people, as well as animals, and what that does to them, right? What the health effects of those contaminants are. And as part of that, I read a paper by Peter Ross, who later became my master’s supervisor, and that paper was about a certain group of chemicals in the three populations of Pacific killer whales, And it was a really cool paper talking about, why the levels were so different between these three types of killer whale populations. What that meant for the health of killer whales. Two of those populations are threatened under some sort of species at risk category. So, it was just really fascinating. It combined my interest in kind of toxicology, so the study of pollution with my interest in wildlife. And then the kind of the third bonus was the potential to kind of move out west where you can be closer to wildlife, or at least a lot easier to interact with wildlife.

KENT DAVIES: During his undergrad, Desforges had taken basic environmental field courses in Northern Ontario but it wasn’t until his masters when he got to experience what research was like in the arctic.

JEAN-PIERRE DESFORGES: So, I was at the University of Victoria with Peter Ross. I had a project working on beluga whales in the Northwest Territories, up in the Beaufort Sea, so the Canadian Western Arctic. So, there we flew out into Inuvik, the kind of closest community with an airport there, and then we traveled remotely by boat to some small islands, and we worked with Inuit hunters from that region. And they collect beluga as part of their subsistence hunt, right? It’s a food source for them, and then we partner with them to collect samples and analyze questions that they’re interested in, right? This is their food, they want to know what’s in it, are the animals healthy, are there pollutants that they need to worry about. And then, you know, questions that researchers are also kind of interested in as well. So that was really, you know, that was my first foray into that field of work. So, not only was it remote, so I was far up in the Arctic, out of cell phone service, camping on a small island with a few other researchers, and then some Inuit families. That was about two, three weeks long, so, you know, an extended period of time, kind of far away, and doing this really amazing work. And that was also my first time in the Arctic, and that kind of really opened up doors, because I’ve been working in the Arctic ever since.

KENT DAVIES: Field research in the Arctic presents a unique set of challenges due to its extreme environmental conditions.

JEAN-PIERRE DESFORGES: It’s really fascinating, I mean, from an environmental perspective, like, the landscapes are incredibly different, right, we’re in different ecosystems entirely, so being up in the tundra is just an amazing kind of difference and feel. It’s 24 hours daylight in the summer, 24 hours darkness in the winter. You know, so you get just that change in perspective from being in a different environment. It’s amazing. The cultural differences are really kind of stark, and you really feel the strength of the people who live in these remote areas, where you think it’d be impossible to survive. And they’ve been there for centuries and millennia. It’s really amazing to kind of work with communities up there and feel that strength and the culture that’s still alive today.

KENT DAVIES: Cooperation with different agencies and building and maintaining relationships with Northern Indigenous communities is crucial to doing any arctic research.[ii]

JEAN-PIERRE DESFORGES: You know, community research anywhere, you know, here in Winnipeg or anywhere, it’s about building relationships, and that takes time. It can be a major challenge for a new researcher, like myself, right? I’m in a new position here and I’m trying to build a permanent program here, where I can keep doing this research. Build on our relationships and answer really interesting research questions, right, that are valuable for both the community and stuff that I’m interested in as well. And that really is— at the heart of those relationships are existing relationships. It’s through my collaborators like, you know, scientists at Fisheries and Oceans Canada, as well as Environment and Climate Change Canada, who’ve been working in the North for decades, right? And they have long-term programs in place with a lot of communities, so there’s a lot of trust built into those relationships.

KENT DAVIES: The region is a unique and valuable place to study climate change; offering insights into how ecosystems respond to rapid changes, and how those changes might affect the rest of the world.

JEAN-PIERRE DESFORGES: I think these days, we all kind of understand what climate change means. How it affects us in our daily life I think is something we need to kind of keep discussing. But the fact of the matter is in the Arctic climate change is real and is visible. We know that the global average temperature has gone up about one degree and the Arctic that has gone up by four degrees in that same time frame, right. So, over the past 50, 60 years or so. Climate change is happening way faster in the Arctic than any other place on the planet. Because of that, things are changing fast, temperatures are way warmer. That affects the land but for the ecosystems I work in, which is primarily marine ecosystems, we’re talking about sea ice as a major driver of change. Likely by the end of the century, the Arctic summers are going to look just like an open ocean. So that’s affecting all the species that live there, as well as it’s introducing a lot of new species that have never been in the Arctic before, whether it’s fish, crabs, invertebrates, whatever. Whether it’s larger animals like different species of seals and whales that have just traditionally been kind of kept out of the Arctic because of that ice, right? Now we’re seeing them more and more all the time. And a really good example of that is killer whales. There’s a lot of communities up in the Arctic that are wondering and they’re worried about killer whales starting to hunt and eat narwhal and the beluga, which are the traditional, you know, food sources for a lot of these communities. So, there’s a lot of really kind of unique and interesting questions that are showing up in terms of the effects on Arctic species, the effects on southern species, you know, what does that mean for Inuit communities? How does that affect the whole ecosystem?

KENT DAVIES: Climate change is also driving up pollution levels in the Arctic. As the ice melts, shifting atmospheric patterns and increased human activity contribute to the mobilization of chemical pollutants.[iii]

JEAN-PIERRE DESFORGES: Obviously other things are happening with climate change, and the big one is with the loss of sea ice humans can start showing up a lot more. So, we’re getting a lot more oil and gas development. The Northwest Passage is opening up so ships can go through for longer periods of the summer than ever before. Tourism is increasing. A lot of these communities are seeing these large tour boats show up nowadays. With all that comes kind of all the other human impacts, right? So, pollution is a big one. And as an environmental toxicologist, this is really one of the fields that I study a lot. Many of the pollutants I study actually come from long range transport. What that means is that these are chemicals, right, chemical pollutants that we use kind of further down south, whether it’s industrial, whether it’s pesticides, whether it’s chemicals in household products. You know, they get flushed down the drain, they end up in the dump, whatever, they get into the environment. And a lot of these chemicals persist for a long time, right? They don’t break down in the environment. So, once they get in the water, some of them tend to be volatile, so they get into the air as well, and they’ll just follow natural currents, right? And if you look at your global map of air and ocean currents, they pretty much head towards the poles. In the northern hemisphere, all the chemicals we use around here slowly make their way towards the Arctic. Because the Arctic is cold, that means all those volatile chemicals, they no longer evaporate, right? So, they drop to the ground, ocean currents kind of end there. When things are cold, things move a lot slower, they can get trapped in snow and ice. So, contaminants just tend to accumulate in the Arctic. You know, it’s a really unique situation because we know that these are remote communities far away from most industrialized areas. And the unfortunate truth is for the communities there that rely on these natural food sources, fish and marine mammals as part of their traditional diet, they’re being exposed to some of the highest levels of these chemicals anywhere in the world, right? So, we’re kind of the ones using them, we’re producing them, we’re the ones throwing them out in the environment. But the people suffering the most are those Arctic Inuit communities and the wildlife that are being exposed to these high levels of contaminants.

KENT DAVIES: Screening for chemical pollution in the Arctic involves a combination of techniques, sampling methods, and environmental monitoring tools to detect a variety of contaminants. Desforges’ primary focus is on the biological sampling of wildlife. 

JEAN-PIERRE DESFORGES: I’m not an analytical chemist, so my colleagues that I work with, you know, they’re the ones with the mass specs, which are either water, there’s stations up in the Arctic, that sample air, for example. We work with wildlife and human samples, so we can take blood, we can take a small piece of fat, so the blubber of a marine mammal. And you can extract the chemicals in those tissues and you can analyze it on these highly expensive mass spec machines. And there is various ways that you can do it whether, you know, we call them targeted or non-target approaches. So, the target approach is you know exactly what you’re looking for, then you analyze your sample for those things, right? So, these are kind of your well-known contaminants. But there was a time where we didn’t know what was present in animals and wildlife and humans in the Arctic. But now we monitor for these things, right? Good examples are things like mercury, PCBs are an industrial chemical that we’ve been studying probably for 50 years or so, but levels are still extremely high in any wildlife and human sample you take in the Arctic. So, we can monitor for those to see if, for example, you know, international legislation to try to reduce these chemicals, you know, are they working or not? So, we can keep track to see if chemical levels are going down alongside with, you know, when regulations are being introduced. And if they’re not, then we know we are doing something wrong. And then the non-target approaches, you know, these are kind of higher-end technologies and you need a lot more expertise, but that you’re essentially just opening the door and you’re saying, you know, what’s in there? You’re trying to identify new chemicals that we haven’t been monitoring before. And that always leads to interesting results, right? We always find new chemicals that weren’t there before, you know, and that really opens up the door for more research, right? Where did this chemical come from? What’s it used in? Has it always been there? We just haven’t seen it before, right? So, we can go back in time, start looking in our archives and looking at old samples to see, you know, when did this chemical start showing up? Does it line up with when we know something happened in the chemical industry, for example, right? Did we ban PCBs and then a new chemical kind of came on the scene? So that’s one of these long-term projects and long-term sampling programs. So, we have samples from, you know, seals and bears going back to the ’80s where we can go back in time and do these kinds of analyses and there’s a whole lot of strength in that kind of monitoring power to identify when chemicals came on the scene and whether regulation are effectively reducing those levels in animals and people.

KENT DAVIES: One of the ways Desforges has been able to study chemical pollution affecting sea wildlife has been through the examination of narwhal tusks.[iv]

JEAN-PIERRE DESFORGES: That’s a good example of a partnership with an Inuit community. That particular project was in West Greenland in a few communities there. So, I did my PhD in Denmark and we did a lot of research in Greenland as there’s the Denmark Greenland connection there. And the researchers I was working with there have, again, really good long-term connections with communities all across of Greenland and narwhal is an incredibly important food source for a lot of those communities. So, for that project specifically, we collected about ten tusks from some hunted narwhals. All the animals were hunted that year and because they were all different ages, I think the oldest animal was close to 60 or 70 years old. And the way that the tusk is formed, it’s kind of like the rings of a tree where every year, a tree gets older, it adds a new tree ring, right? So, when you take a cut of a tree, you can just count the rings and essentially get the age of the tree, right? The narwhal tusk is the exact same way. So, it grows incrementally, so the bigger it is, usually the more layers that you can find. We call these annual growth layer groups. So, the older the animal, the more annual groups we can sample. So, we can actually go back in time, and if we measure things like mercury, for example, in each of these annual layers, now we have a record of the exposure of that animal to mercury over its full lifespan. So, we went back 70 years and now we had this amazing track record of essentially what happened to this animal for the past 70 years in terms of mercury exposure.

KENT DAVIES: Desforges’ PHD research using Narwhal teeth has led him to study other animals whose teeth can provide valuable insights into changing Arctic ecosystems. Leading us back to our research question… what can polar bear teeth tell us about the impacts of climate change?

JEAN-PIERRE DESFORGES: The same principle applies to most mammalian teeth, so the polar bear is no exception. We get that same annual deposition of cementum in polar bear teeth. We can analyze that, again, over the full lifetime of an animal to understand something about its life essentially. And depending on what we sample and what we analyze in those teeth, we can learn a lot of information. The narwhal study, we included mercury as well as stable isotopes, which tell us a lot about the diet of the animal. For this new project on polar bear teeth, we’re looking at the thickness of the annual layers that are deposited in the tooth of the bear. And it turns out, we know this from previous studies of a lot of different types of animals, that the thickness of these annual growth layers tell us a lot about the nutritional quality of the bear that year that tooth was deposited in. So, essentially by analyzing that, it can tell us something about kind of their nutritional quality. Do they eat a lot of food that year? Were they nutritionally stressed? It can tell us about the reproductive status. So, essentially reproductive females often won’t eat as much, and they’re releasing a lot of energy, right? They’re producing milk for their offspring, for example. And because of that, we actually know it changes the size of these growth layer groups. So, if you’re kind of able to decipher the information that’s stored in the teeth of these animals, we can learn a lot about kind of what’s been happening in the life of that animal for the past 10, 20, 30 years, depending on how old that animal is. With teeth samples that we have through, again, great collaborations with Environment Canada and DFO, we’re trying to understand how has climate change affected polar bear populations for the past 40, 50 years? And the best way to do that is with these great long-term data sets stored in the teeth of these animals.

KENT DAVIES: The project, Reconstructing life history and climate associations from teeth of polar bear and ringed seals in Western Hudson Bay examines how the productivity of polar bears are linked and affected by long-term environmental change.[v]

JEAN-PIERRE DESFORGES: This particular project is focused in Western Hudson Bay. We’re collaborating with communities primarily in Nunavut, and Arviat is probably our strongest community partner for this project. So, I was just there last week meeting with community members, meeting with the hunters and trappers organization, we also did some workshops with some local high schools there to kind of teach kids about our project, some of the science that we’re doing. So, it was a really kind of cool experience to engage with the community. On top of that, Environment and Climate Change Canada has had a long-term monitoring program with polar bears out of Churchill, and they’ve been doing this since the early 1980s, and that’s kind of an independent program that they run, and that’s a live sampling program. So, they’ll go out and capture bears and take samples, take measurements for a long time. They’ve been taking teeth from bears as well. And with that particular program, they’ve been able to sample something like 4,000 bears. A lot of those are repeat samples of the same individual over time. Each time they sample, they have information on things like the body condition of the bear, right? How fat is it? Is it a reproductive mother? Is it pregnant? Does it have cubs? How many cubs does it have? If they catch it again the next year, they kind of know did that the cub survive? So, they have an amazing data set of information on polar bears kind of in that region of Western Hudson Bay. And then we can get additional samples from harvested bears as well as ring seals. So, this project is focused on kind of combining information from polar bears and their primary prey, which is the ring seal, from the same region. And the ring seal samples all come from harvested seals primarily from Arviat. And again, there we’re doing the same thing. We’re collecting teeth from those seals. We can count those annual layers and the cementum of the seal to first get their age, right? We just count them when we know how old they are. And then we get that kind of loaded physiological, ecological information that’s stored in kind of the morphology of those layers. And we have to try to unpack that and understand what are those layers telling us about the life of those animals.

KENT DAVIES: The samples end up here at the newly established, eco-toxicology and wildlife stress lab here at the University of Winnipeg. Using a variety of research approaches including genomics, molecular biology, in vitro experiments, population biology, and ecological modeling, the lab helps provide a greater understanding of human-wildlife-environment interactions to better help wildlife conservation and chemical management.[vi]

JEAN-PIERRE DESFORGES: It’s funny going from a student to not that long ago to start in your own independent lab. It’s such a huge transition, you know, it requires a different way of thinking. Probably the strength of my own research program is the collaborations that I have in place. So, I’ve been, you know, lucky to be able to kind of take off running with those collaborations at DFO and Environment Canada. As the name kind of suggests, I tried to pick a broad term for kind of my lab. Trying to kind of extend what I’ve been doing over the past ten years into my own research program and it’s been really exciting and it’s been really cool to expand on different approaches that I’ve used in the past. So, I use a lot of, you know, field-based approaches to go collect samples in the past. I’ve done a lot of immunology work where we can collect, you know, blood from animals, and then we can do kind of experiments with those white blood cells to understand, you know, how are chemicals affecting the immune system, for example. So, I’m trying to grow that kind of program and one way we do that here at the university in my lab is I have a cell culture facility where we can collect cells from some of these animals that we sample from in the wild and then we grow them in the lab. So, I have several grad students right now that are trying to grow cells from different animals to understand, you know, what is that connection between exposure to contaminants like mercury and PCBs and pesticides to potential mechanisms of effects, right? That may actually impair the health of an animal in the field. And studying that in the field is extremely challenging, as you can imagine. But isolating that system and growing cells in the lab, exposing them to chemicals and then looking at, you know, various bioassays, be they gene expression to enzyme activity to try to understand some of those mechanisms. And that’s a major component of my research lab here. As well as some of these projects relating to teeth and tusks and hair and feathers, right? These are all, we call them inert chronological tissues, right? Because once they’re deposited, they’re not really modified anymore. They can last, you know, forever. So, we can even use archaeological samples to kind of go back in time even longer and analyze some of these samples for, you know, questions like how climate change has affected the, you know, forging ecology or exposure to contaminants over long periods of time.

KENT DAVIES: According to Desforges, the location of the eco-toxicology and wildlife stress lab is crucial to the success of the project.

JEAN-PIERRE DESFORGES: A lot of the projects I have ongoing now are through communities in Nunavut and working with researchers in Churchill. And the reason those work so well is that direct access. Starting next week, so the polar bear harvest in Nunavut is beginning. The hunters will be going out and collecting polar bears. And I have a project now where they’ll be sending tissues to us in the lab where we can try to isolate cells and grow those cells in the lab for these kinds of exposure experiments I was talking about. And the only reason we can do that and the cells can stay alive is because there’s a direct flight, Winnipeg, to Rankin Inlet, which is one of the communities that we work with. And Rankin Inlet is only a 45-minute flight from Arviat, which is another community that we work with. So, you know, in a matter of hours, there could be a sample collected in Nunavut and they can be in our lab here in Winnipeg and then we could work on those samples right away. So, it’s a really unique opportunity to have those collaborations that just don’t exist in many other places. It’s really fascinating. It’s also been great for recruiting students and getting people to the lab to do this kind of work has been really nice. I mean, I admit I never thought I’d move to Winnipeg and start a research career here. Getting the job opportunity was, you know, a great chance to move here and then come to that realization that there’s probably no better place in Canada to do this type of work.

KENT DAVIES: By uncovering the impacts of climate change and chemical contaminants in the arctic, Desforges believes this type of research can help drive policy changes towards reducing pollution, safeguarding public health, and protecting ecosystems.

JEAN-PIERRE DESFORGES: As a young person interested in environmental work, it was really about figuring out what can I do with my life that’s going to have an impact, right, like feeling like my work was impactful. And I stumbled into toxicology, environmental toxicology kind of haphazardly, but the reason I’ve been driven in this field has been because of the direct implications of the work. I find it really rewarding that not only do I get to work with communities, work in amazing places and have great experiences, but the work that we do directly helps manage environmental chemical issues and the best example of that is international regulation of persistent organic pollutants, these are a class of chemicals that we study a lot because they make their way to the Arctic quite easily and they last a very long time. If you ever heard the term forever chemicals, it’s kind of in the news a lot lately, these are a group of perfluorinated chemicals within that kind of similar family. And these are regulated through the Stockholm Convention on Persistent Organic Pollutants, which is a UN initiative signed by over 180 countries. And through that convention, the primary driver of management of chemicals is Arctic research and rightly so, because if a chemical can be transported far away from its source, if it can last in the environment of really long time, so it’s persistent, and if it’s toxic, we’re going to detect it in Arctic wildlife, right? By definition, it has been long-range, transported somewhere, and it hasn’t broken down, so just by detecting it in the Arctic, we’re already kind of checking off most of the boxes for chemical regulation as part of the Stockholm Convention. And then on top of that, the work that I’m interested in, which is one of the effects of the chemical. That’s the toxicity side. And again, if we can show that these chemicals do have toxic effects, then we can submit that information, and we do so in published papers and reports. We can submit all that information to policymakers at the Stockholm Convention, and then they take all that in and they decide whether or not a chemical should be regulated at the international level, right? And that has led to the banning of many chemicals, including PCBs as a good example. Another really great example are these brominated flame retardants, so they’re called PBDEs, and that kind of replaced PCBs a lot in the early days, and again, because of arctic work, we found that levels were increasing in wildlife across the Arctic, we showed that these chemicals were toxic, and then we banned them in various phases throughout the 2000s, 2010s, and then now we’re seeing levels decline again. It’s an amazing realization that the work you do can lead to positive change. That’s really at the heart of a lot of the stuff that I’m interested in, and I’m hoping that by doing so, not only do we benefit the wildlife that are exposed to these contaminates but also all the communities that are consuming these wildlife and are being exposed to these high levels of chemicals, and they have no right to be exposed to those. So if I can contribute to that in a meaningful way, then I’m just really thrilled to be part of that.

KENT DAVIES: You’ve been listening to Research Question. Research Question is produced by the University of Winnipeg Research Office and the Oral History Centre.

The University of Winnipeg is located on Treaty 1 Territory, the heartland of the Metis people.

Written, narrated and produced by myself, Kent Davies.

Our theme music is by Lee Rosevere.

For more on University of Winnipeg research, go to uwinnipeg.ca/research

For more information on the University of Winnipeg Oral History Centre, and the work that we do, go to oralhistorycentre.ca.

Thanks for listening.

 

[i] Andrew E. Derocher, Nicholas J. Lunn, and Ian Stirling. “Polar bears in a warming climate.” Integrative and comparative biology 44, no. 2 (2004): 163-176. Ian Stirling, and Andrew E. Derocher. “Effects of climate warming on polar bears: a review of the evidence.” Global Change Biology 18, no. 9 (2012): 2694-2706; Voorhees, Hannah, Rhonda Sparks, Henry P. Huntington, and Karyn D. Rode. “Traditional knowledge about polar bears (Ursus maritimus) in Northwestern Alaska.” Arctic (2014): 523-536; Douglas Clark, Kyle Artelle, Chris Darimont, William Housty, Clyde Tallio, Douglas Neasloss, Aimee Schmidt, Andrew Wiget, and Nancy Turner. “Grizzly and polar bears as nonconsumptive cultural keystone species.” Facets 6, no. 1 (2021): 379-393.

[ii] Arctic and Northern Policy Framework, Government of Canada. Accessed December 4, 2024.

[iii] Hayley Hung, Crispin Halsall, Hollie Ball, Terry Bidleman, Jordi Dachs, Amila De Silva, Mark Hermanson et al. “Climate change influence on the levels and trends of persistent organic pollutants (POPs) and chemicals of emerging Arctic concern (CEACs) in the Arctic physical environment–a review.” Environmental Science: Processes & Impacts 24, no. 10 (2022): 1577-1615; Desforges, Jean-Pierre, Steven H. Ferguson, Anaïs Remili, Melissa A. McKinney, Cortney A. Watt, and Cory JD Matthews. “Assessment of persistent organic pollutants in killer whales (Orcinus orca) of the Canadian Arctic: Implications for subsistence consumption and conservation strategies.” Environmental Research 244 (2024): 117992.

[iv] Jean-Pierre Desforges, Rune Dietz, Frank F. Rigét, Aurore Aubail, Eva Garde, Per Ambus, Robert Drimmie, Mads Peter Heide-Jørgensen, and Christian Sonne. “Analysis of narwhal tusks reveals lifelong feeding ecology and mercury exposure.” Current Biology 31, no. 9 (2021): 2012-2019. Desforges, J. P., B. Mikkelsen, M. Dam, F. Rigét, S. Sveegaard, C. Sonne, R. Dietz, and N. Basu. “Mercury and neurochemical biomarkers in multiple brain regions of five Arctic marine mammals.” Neurotoxicology84 (2021): 136-145.

[v] Polar bears, seals and their molars, UWinnipeg News, October 9, 2024. Accessed November 5, 2024.

[vi] Ecotoxicology and Wildlife Stress Lab, Accessed November 5, 2024.