Polar Ecosystems in Transition: An interdisciplinary case study of the effects of climate change on temporal trends in contaminant accumulation, foraging ecology, and human use of polar bears (Ursus maritimus)

This project is an initiative encompassing various aspects of the impact of climate change on polar bears (Ursus maritimus). The project is examining the effects of climate change on the bioaccumulation and (spatial and temporal) trends of chemical pollutants in polar bears (contaminants, R. Letcher), and the relationship between seal and bear growth over time, which allows to ascertain the direct relationship between polar bears and their principal prey, (predator-prey, M. Dyck). Two other components involves the collection of traditional ecological Inuit knowledge on climate change and the polar bears in Davis Strait (Inuit knowledge, M. Kotirek), and an assessment of change in foraging ecology in two populations over the last 10 – 15 years and assessment of the link between annual survival and individual variation in foraging (foraging ecology, E. Peacock). 

Contaminants and foraging

Robert Letcher EC scientist | Photo: ECCurrently used chemicals that have been found to be “emerging” as contaminants in Arctic wildlife, food webs and ecosystems such as in polar bears include polyfluoroalkyl compounds and their precursors or collectively known as PFCs. PFCs are currently used in e.g., water-repellent coatings such as on carpets and furniture coverings as well as in non-stick coatings for pots and pans. Other emerging contaminants include brominated flame retardant (BFR) materials such as polybrominated diphenyl ethers (PBDEs), which are used in furniture and electronics, have also found their way into polar bears via their Arctic food chain. The main goal of this component of the present IPY project is to investigate changes over time in BFR and PFC patterns and levels in polar bears using tissues (fat, liver and blood) for bears from populations spanning the Canadian Arctic. Utilizing new sample collections and using available archived samples from as many as possible time points as is permissible will permit these BFR and PFC temporal and geographic studies. We are also examining whether climatic (warming) change imposed alterations on ice conditions and duration is reflected in differences in polar bear diets (using ecological tracers of diet and position in the marine food web) and bioenergetics, and thus on the levels and patterns of BFRs and PFCs in polar bears depending on the population.

Additional polar bear tissue samples are required for these 2007-2008 studies, but 2007 contaminant data generated so far suggests that PBDE levels are somewhat lower now than they were in 1999-2002, which may reflect changing human input and use patterns at their sources in lower latitudes. Although the PFC trend results are also very preliminary, PFC patterns among bear populations studied appear to be similar to those reported in 1999-2002, which is the only other time point for PFC reports in the tissues from Canadian polar bears. PFC concentrations in bears from southern Hudson Bay were the highest among zones and samples studies so far, and are comparable to levels reported in 1999-2002. It would appear that the geographical sources of PFCs have not changed and/or increased substantially over the last 5 to 8 years.

Inuit knowledge

Inuit knowledge and values are trying to be used in environmental and wildlife management and throughout the Government of Nunavut.  Further, the Nunavut Land Claims Agreement created a wildlife management system with a principle of an effective role for Inuit in all aspects of wildlife management, including research.  This project examines ways that Inuit knowledge can be used in environmental management by speaking with Inuit and Northerners about polar bears, climate change and Inuit knowledge.

To do this, we speak with elders and northerners in Kimmirut, Pangnirtung and Iqaluit regarding their knowledge of polar bears, climate change and Inuit knowledge.  The elders, identified through Hunters and Trappers Associations and Conservation Officers, are spoken with about their thoughts of polar bears, climate change, Inuit knowledge and their interactions.

Northerners are selected by randomly selecting households and asking residents to participate in the survey.  In addition to their thoughts regarding these issues, other variables are collected to identify possible correlations.

This project will identify what range of knowledge and values Inuit and Northerners have regarding polar bears, climate change, and Inuit knowledge.  In accomplishing this, the project engages elders and the northern public in discussions regarding polar bears, climate change and Inuit knowledge and documents and makes available the varying viewpoints of elders and northerners regarding these issues.  The availability and communication of this knowledge can allow discussion and consensus building on these sometimes controversial issues.

Predator-prey

Polar bear near Cape May, shores of the Hudson Bay | Photo: ECMost of Canada's polar bears exist in Nunavut. Bears play an important cultural, spiritual, and economic role in Inuit society. Climate change could have a detrimental effect on bears, and therefore also on the Inuit culture. Currently, there is very little information available about how, and if, climate change is affecting bears in Nunavut. Biological information of already harvested polar bears and seals is collected (i.e., an non-invasive technique to obtain samples; sex, age by counting growth layer groups (GLGs) in teeth, body length, chest girth) from one area in the High Arctic (i.e. Lancaster Sound [LS]), and one southern area (i.e. western Hudson Bay [WH]) for comparison. Growth layer thickness of animals born in the same year (polar bear and seal cohorts) will be compared, and correlated with environmental data (i.e. Arctic Oscillation Index, ice data, ambient air temperature, etc.). Thickness of growth layers indicates food abundance, and how it affects growth. These growth layers provide indirect information about habitat and food chain health and productivity.

By examining climate information from the past 30 years, as well as tooth growth layer thickness for the same time period, it will be possible to examine how the abiotic factors (i.e., climate) affected biological factors (i.e., growth or condition) in the past. The collection, and continued monitoring, of biological data of bears and seals can indicate how bear and seal populations are doing with respect to climate, and whether any immediate action plans (i.e., recovery strategies) need to be devised and implemented. Continued collection of biological data of bears and seals can indicate changes in habitat/ecosystem and food chain. Traditional knowledge of hunters can help supplement the understanding of these processes.

Polar bear captured to be weighed and tagged  | Photo: ECEstablishing a baseline of morphometric data of harvested polar bears will allow to compare these measurements at a later point in time, and coupled with climate data, it will allow to make inferences whether harvest regimes or climate change might affect polar bear populations in specific ways.

Key activities are photographing microscopic slides of tooth sections of polar bears and seals. The next step is to identify GLGs, measure their thickness, and group bears/seals into cohorts to assess a possible correlation among trophic levels, and to determine whether climatic data is also correlated to GLG thickness. To date, about 500 slides of polar bear tooth sections have been photographed, and are being assessed whether the quality and scale is suitable for GLG thickness measurements. Samples of seals (teeth and measurements) are expected to be provided from Resolute, or alternatively, from DFO Canada (in case none were collected in Resolute).

Principal Investigator
NameAffiliationMailing AddressE-mail AddressTelephone
Elizabeth PeacockGovernment of NunavutBox 209, Igloolik, Nunavut
X0A 0L0
epeacock@nunavutwildlife.ca867-934-2186

Project Team
NameAffiliationRole
(i.e., Co-applicant, Collaborator, Other key contributor, e.g. graduate student, Elder, technician etc.)
Contact Information
Robert J. LetcherWildlife Toxicology and Disease Program, Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment CanadaCo-applicantTel.: 613-998-6696
Fax: 613-998-0458
E-mail: Robert.letcher@ec.gc.ca
Moshi KotierkDepartment of Environment, Government of NunavutCo-applicantTel: 867-934-8434
E-mail:mkotierk@gov.nu.ca
Markus DyckNunavut Arctic CollegeCo-applicantBox 1133, Iqaluit, NU  X0A 0H0
Willie SoonHarvard UniversityCollaboratorwsoon@cfa.harvard.edu
Christina LockyerAge DynamicsCollaboratorChristina_Lockyer@hotmail.com
Steve FergusonDFO CanadaCollaborator, possiblyFergusonSH@dfo-mpo.gc.ca