Date of Award

Spring 2021

Project Type

Thesis

Program or Major

Biological Sciences

Degree Name

Master of Science

First Advisor

Nathan B Furey

Second Advisor

Nigel E Hussey

Third Advisor

Elizabeth A Fairchild

Abstract

Seasonal fluctuations in environmental conditions drive ecosystem processes across the globe, particularly at the earth’s poles. Seasonality in Arctic marine systems is exemplified by an annual summer ice-off that promotes primary productivity blooms and provides nutrients for upper trophic level consumers who often migrate to these productive areas. Arctic char (Salvelinus alpinus) are an economically and culturally important salmonid that migrate from freshwater spawning locations into the marine environment, presumably to feed. In this thesis, I describe two studies investigating the movement and feeding of Arctic char within Tremblay Sound, Nunavut, Canada, a newly designated National Marine Conservation Area (Tallurutiup Imanga). Through the combination of acoustic telemetry and ice data, I found Arctic char migrating into Tremblay Sound before ice-off began in the marine environment, which validates visual observations from the 1950’s and 1970’s. I found potential evidence of multiple populations of Arctic char utilizing Tremblay Sound in the summer or ontogenetic shifts in migration distance. Stomach content analysis suggested that char consume high rates of food during the ice-off season within Tremblay Sound. The frequency of occurrence certain prey items, notably Arctic cod (Boreogadus saida) and Onisimus spp., changed between years, and was likely related to local ice conditions and differences in sampling time between years. Collectively, this thesis expands our understanding of the interactions between movement and feeding during the marine component of Arctic char migration. The results have important implications for management and the potential resiliency of Arctic char in an ever-changing high Arctic.

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