Northern Labrador

Ringed seal health in response to environmental change

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High trophic level ringed seals (Pusa hispida) are particularly vulnerable to persistent organic pollutants (POPs) such as PCBs. Although long-range transport of persistent organic pollutants (POPs) through air currents, ocean currents and rivers are responsible for the delivery of the majority of POPs found in Nunatsiavut, local sources also exist with two hotspots being associated with two former military radar sites at Saglek and Hopedale. Up to 60% of ringed seals studied along the Northern Labrador coast are contaminated by local sources and average 

concentrations in adult male ringed seals exceed a threshold for endocrine and immunotoxic effects. Gene transcripts and metabolite levels measured in ringed seals from Labrador have been associated with PCB concentrations, suggesting that some 

adverse effects have been caused by the combination of local and long-range sources. Altered metabolite levels were also observed in ringed seals collected during an unfavorable ice condition year, suggesting health- or diet-related responses to climate change. This study uses omics approaches (transcriptomics and metabolomics) to carry out a health effects assessment in ringed seals in Northern Labrador. Gene transcript and metabolite profiles in a priority population of ringed seals will be 

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evaluated over time as a function of both contaminant exposure and climate-related stressors. This project will deepen our understanding of contaminant related health effects in marine mammals by building on our earlier transcriptomic and metabolomic studies. Our results have bearing on the health of the ringed seal population in Labrador, in addition to those community members that rely on this species as important country food.

Mallory Carpenter