Ringed seals (Phoca hispida) have been used as bioindicator species of environmental contamination in Canada since the 1970s. In the present study, seals were harvested during subsistence hunts in four regions of the Canadian Arctic: Beaufort Sea, Arctic Archipelago, Hudson Bay, and coastal Labrador. An extensive suite of persistent organic pollutants (POPs) was determined in seal blubber collected for multiple years between 1972 and 2016. Results from this long-term study indicate geographical differences in the contaminant concentrations in seals and the significant general decrease of most POPs, including polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and related compounds, chlordanes (CHL), and hexachlorocyclohexanes (HCH) over time in ringed seals. Overall, results suggest that North American and international regulations have led to the long-term reduction of most POPs in Canadian Arctic ringed seals by reducing emissions from primary sources. However, other sources of legacy compounds (e.g., environmental reservoirs) as well changes in food web composition and structure in relation to climate changes could also be influencing the very slow rates of decline, or stable levels, of contaminants found in seals at some sites.
Supplemental Information
The Northern Contaminants Program (NCP, http://www.science.gc.ca/eic/site/063.nsf/eng/h_7A463DBA.html) was established in 1991 in response to concerns about human exposure to elevated levels of contaminants in wildlife species that are important to the traditional diets of northern Aboriginal peoples. Early studies found a wide variety of substances, many of which had no Arctic or Canadian sources, but which were, nevertheless, reaching unexpectedly high levels in the Arctic ecosystem.
The Canadian Cryospheric Information Network (CCIN, https://www.ccin.ca/) and the Polar Data Catalogue (PDC, https://polardata.ca/) have been developed over the past two decades through collaborative partnerships between the University of Waterloo and numerous government, university, and private organizations to provide the data and information management infrastructure for the Canadian cryospheric community. The PDC is one of Canada’s primary online sources for data and information about the Arctic and is Canada's National Antarctica Data Centre.
Polar Data Catalogue Canadian Cryospheric Information Network Metadata Record:
https://www.polardata.ca/pdcsearch/PDCSearch.jsp?doi_id=10780