Climate change consequences for an Arctic apex predator: polar bears as ecological indicators

点击翻译按钮获取中文摘要

Ice-covered Arctic marine ecosystems are undergoing rapid ecological change as the climate warms. The effects are notable in sea ice characteristics, primary productivity, and ecosystem structure that affect polar bears (Ursus maritimus) which are a sea ice obligate species. The main working hypothesis of this proposal is that changes in the ecology and biomarkers of polar bears are associated with shifts in ecosystem structure and phenology caused by warming induced alteration of sea ice habitat. The objectives are to develop new monitoring metrics, document the consequences of climate change on polar bears, predict future changes, and examine the ecological interactions of polar bears with prey and scavengers. Objectives include identification of the mechanisms associated with polar bear population change over time to predict the effects of global warming. Long-term sampling in the key research populations (i.e., Beaufort Sea, Western Hudson Bay) allows investigation of the spatial dynamics, habitat use, and population dynamics in relation to changing environmental conditions. Over the next five years, my research group will examine: the spatial ecology and habitat use of polar bears using remote sensing to assess habitat use relationships with life history parameters, develop interdisciplinary means of assessing life history events and stress from microanalysis of tissues, use integrated life history and energetics modelling to explore the future status of polar bears, and examine the predator-prey dynamics of polar bears and the role of the bears as a keystone predator. Methods include: satellite telemetry, remote sensing, biomarkers, ecosystem dynamics, mathematical modelling, and remote cameras. The focus of the project is to integrate methods to obtain greater insight than possible from a single technique. Partnerships with Environment and Climate Change Canada and Fisheries and Oceans increase efficiency and samples sizes. Species responses to global warming are of fundamental interest to ecologists and managers yet the mechanisms of change and predictions for such changes are poorly understood. A mechanistic understanding of the processes that result in both individual and population response is necessary for predicting future conditions for a species. Integration of methods will provide novel insights. As a flagship species of climate change, polar bears have great local, national, and international interest.