Winter ecology of polynya and floe edge habitats in eastern Hudson Bay: impacts of climate and hydroelectric developments on sea ice ecosystems


***Monday, April 30, 2012
Redfield Auditorium - 12:00 Noon
Dr. Joel Heath
NSERC Postdoctoral Fellow, Mathematical Biology Program
Dept. Mathematics, University of British Columbia

Polynyas and floe edges in east Hudson Bay provide important winter habitat for wildlife, particularly Common Eiders and their benthic invertebrate prey. Inuit have reported extensive changes to the dynamics of these habitats associated with hydroelectric developments and climate related environmental change. The increasing frequency and severity of mass-mortality events of eiders is of particular concern, representing the proverbial ‘canary in the coal mine’ for the changes occurring in this ecosystem. My research program investigates how sea ice and oceanographic conditions influence the foraging and community ecology of eiders in these habitats, combining Inuit knowledge and quantitative ecological approaches. Eiders require open water to dive for food like mussels and sea urchins, and so their winter foraging range is constrained by sea ice extent. Strong currents can maintain open water, but influence diving and foraging costs. Inuit knowledge indicates currents are slowing down, which may reduce diving costs for eiders but also affects the availability of these habitats through the winter. Based on long term winter field studies, I have developed a quantitative individual based model that considers these trade-offs and provides a mechanistic understanding of winter survival and mortality that can be linked to landscape and population dynamics. In conjunction with oceanographic deployments, my program is now using aerial and underwater time lapse imaging technologies to simultaneously monitor wildlife and sea ice dynamics in these habitats as part of a multi-scale community based research and monitoring program developed during International Polar Year. I will present a summary of physical and biological changes observed by Inuit and academic research, demonstrate how quantitative ecological models can help understand current and future impacts of environmental change, and propose future directions for expanding our community based monitoring programs in the eastern Arctic including the development of positive working relationships with the hydroelectric industry.