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Research Interests:
Early in my time working in the Arctic, I recognized that the August Krogh principle in comparative physiology can apply nearly as well to geographical regions as it does to individual species. That is to say, for a given physiological phenomenon there may be a region where it can be most effectively studied based on the environmental challenges specific to that region. Based on this observation and my personal passion for northern science and education, my research interests have organically grown to focus on ecophysiological questions that are effectively addressed in the Arctic.
Thermal physiology in a variable and warming north
The thermal challenges encountered by Arctic organisms are remarkable over diurnal, seasonal, interannual, and geological timescales. Animals in the Arctic can face extreme cold, however, during the Anthropocene, the Arctic has warmed at over twice the average global rate. Collaborators and I have recently recorded water temperature fluctuations in Arctic fish-bearing rivers of over 10°C in a day and over 20°C in under two weeks with peak temperatures over 21°C. My past and ongoing research is focused on the impacts of these challenges on the cardiorespiratory performance and migratory ecology of Arctic char.
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An Arctic char navigating warm shallow water on its annual upriver migration
Exercise physiology in the land of long-distance migrants
Resource availability in the Arctic is highly spatially and temporally structured. As such many species found in the north undertake impressive migrations to optimize their access to feeding, breeding and overwintering habitat. For example, the Arctic tern undertakes the longest distance migration of any animal in the world, travelling between the Arctic and Antarctic. As such questions related to training and high athletic performance can be studied effectively in the region. My current research in Arctic char is concerned with the acclimation and adaptation of exercise physiology to local migratory conditions.
A Jaeger chasing down a seagull. Both species breed in the north and can undertake impressive migrations to get there
The physiological ecology of ‘feast and famine’ in northern fishes
The extreme seasonality at high latitudes means that many resources (e.g. spawning habitat and food) are only available for brief pulses. As such many Arctic species possess physiological adaptations that facilitate the exploitation of those resources. I am currently studying how the digestive and metabolic physiology of anadromous Arctic char allows them to achieve and maintain functional energetic condition with periods of fasting or restricted feeding spanning up to 20 months.
In addition to the pronounced seasonality, human activities can influence the pulsatile nature of resource availability. For instance, commercial fisheries provide a large resource pulse for scavengers such as gulls, jaegers, and foxes. In the future, I hope to examine how these scavengers naturally exploit pulse resources and how fisheries alter their annual energy dynamics.
Gut size relative to body size following summer feeding or overwinter fasting and sexual maturation in Arctic char
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