Moving Through a Changing North: Exploring the Physiological Capabilities and Movement Behavior of Arctic Char

Global climate change is expected to be most prevalent in the Arctic; to what degree native species can tolerate potential changes remains unknown. One species of particular interest is Arctic Char (Salvelinus alpinus), a salmonid that migrates between freshwater and marine environments many times over its life. Evidence suggests that critical connecting watercourses have already experienced change including decreased flows which make passage more difficult (physically) and decreasing passage windows. To explore this in greater detail, we are studying the physiology and movement behaviour of Arctic Char from the Hingittok Lake-Nulahugyuk Creek system, Nunavut. Swimming performance and energetics will be evaluated using a creek-side swim chamber that will simulate flows representative of current and predicted future climates of the north. Arctic Char will be subjected to fatiguing exercise tests to evaluate capabilities and physiological stress. Also, movement behaviour in the creek will be addressed using PIT tag monitoring arrays and visual observations. The migratory process in the creek (between the lake and ocean) will be monitored relative to flow patterns in the creek. Previous work has identified areas with dispersed flows through boulder gardens where the potential for migratory barriers is high. Movement though these areas will be evaluated in 2012 and during the second phase of the study (2013), a portion of the channel will be manually manipulated to potentially improve passage potential for fish. Combined, the physiological and movement studies will endeavour to answer questions about how alterations to flow regimes in northern watercourses may affect native fishes. We will also determine if artificial manipulation to the fluvial geomorphology of channels can offset the physiological and physical challenges experienced by fish relying on these watercourses for critical portions of their life cycle. Findings may be applied to assist in the maintenance and recovery of other fish stocks that are of cultural and subsistence value to the Inuit people.