Victorine Lambert
McGill University
M.Sc. candidate
Supervisor: Melissa McKinney
Steve Ferguson, University of Manitoba
Start: 2024-05-01
End: 2026-04-30
M.Sc. candidate
Supervisor: Melissa McKinney
Steve Ferguson, University of Manitoba
Start: 2024-05-01
End: 2026-04-30
Project
Exploring the Ecological Implications of Arctic Sea-Ice Loss: Insights from Killer Whale Diets and Contaminant LevelsThe accelerating retreat of Arctic sea ice, driven by global warming, presents challenges as well as novel opportunities for Arctic ecosystems. In particular, the expanding territory of seasonal species in response to changing ice conditions offers a unique lens through which to understand ecological dynamics. In the Canadian Arctic, the extended presence of killer whales (Orcinus orca), typically from July to October, underscores this ecological shift, as these predators exploit new avenues to opportunistically feed on higher latitude species such as ringed seals or narwhals among the redesigned Arctic waters. Simultaneously, the phenomenon of global distillation, whereby persistent organic pollutants (POPs) are transported towards polar regions due to their physicochemical properties, poses significant concerns for Arctic marine life. The anticipated rise in POPs levels within Arctic waters raises questions about the implications for upper trophic level predators like killer whales. Their position atop the food chain makes them great bioindicators of ecosystem contamination. To address the pressing ecological questions around the impact of global climate change on Arctic ecosystems, we propose a comprehensive investigation of contaminants through compound-specific isotope analysis of blubber fatty acids in Canadian Arctic killer whales. By correlating δ13C values, deriving from primary producers indicating dietary sources, with levels of persistent organic pollutants (POPs) in 43 blubber samples from the Canadian Arctic between 2020 and 2022, we aim to investigate the potential relationship between δ13C and contaminant intake. Preliminary analyses of blubber fatty acids are expected to reveal disparities in feeding behaviour from pelagic to coastal sources, reflecting changes in prey availability and distribution influenced by sea-ice dynamics. Subsequent determination of contaminant levels within individual blubber samples will be statistically evaluated for their correlation with δ13C values, shedding light on the relationship between diet composition and contaminant levels through novel techniques. This research endeavours to provide critical insights into the ecological ramifications of shifting dietary patterns among Arctic predators in response to changing environmental conditions and their consequences of contaminants levels over time. By elucidating the linkages between diet, contaminant intake, and biomagnification processes within marine ecosystems, our study aims to equip stakeholders with valuable tools for informed decision-making and targeted interventions to mitigate pollutant impacts in the Arctic. In sum, this interdisciplinary approach not only advances our understanding of Arctic ecosystem dynamics but also underscores the urgent need for proactive measures to safeguard the health and integrity of these vulnerable environments in the face of ongoing climate change.
