Understanding the interactions and impacts of climate change and contaminants (exposure, effects) on Arctic seabirds at their southern range limits

Arctic wildlife are currently impacted by multiple stressors, including contaminant levels in seabirds that are of potential concern, and climate change with record-breaking temperatures and rapid changes in ice coverage that are important for wildlife reproduction and survival. Climate change can impact wildlife populations through a mismatch in the timing of breeding and food availability that is important for successful reproduction. For Arctic seabirds, phytoplankton bloom immediately after the ice departs and sets a timeline that determines when maximal food is available for seabird nestlings. Climate change can cause ice to melt more rapidly than seabirds can respond, resulting in a mismatch between the time when seabirds rear their offspring and the time when the maximum amount of food is available for them. The end results may include poor growth of the chicks, excessive and even unsustainable energy expenditure, and possibly impact the survival of the birds. The flexibility of the birds behaviors to respond and adapt to the changes in food availability, contributes to the resiliency of the birds in responding to climate change. Yet the seabirds exposure to contaminants can alter their behavior, endocrine function, and energy expenditure. Our research objectives, established in 2016-17 and repeated in 2017-18 and 2018-19, are as follows:1. To characterize the contaminant exposure of incubating thick-billed murres, specifically mercury, and NCP-priority brominated compounds and perfluorinated compounds; 2. To measure thyroid hormones, corticosterone and nutritional biomarkers, to understand possible interrelationships among contaminant concentrations, changes in hormone status, foraging behaviours, nutritional status, and energetics, in the same individuals; 3. To measure biomarkers that characterize the nutritional status of the same individual birds, and hence identify possible interrelationships with the reduced ice coverage (notable in the past 2 years), the birds altered prey selection, increased energy expenditure, and greater time spent diving while foraging for fish; 4. To use statistical path analysis to link contamination with energy expenditure and intake with hormone levels and DNA methylation status.NOTE: Kim Fernie and Kyle Elliot are both Principal Investigators for this project.