Possible Effects of Climate Warming on Selected Populations of Polar Bears (Ursus maritimus) in the Canadian Arctic

摘要: Polar bears depend on sea ice for survival. Climate warming in the Arctic has caused significant declines total cover and thickness of polar basin progressively earlier breakup some areas. Inuit hunters areas four bear populations eastern Canadian (including Western Hudson Bay) have reported seeing more near settlements during open-water period recent years. In a fifth ecologically similar population, no changes yet been by hunters. These observations, interpreted as evidence increasing population size, resulted increases hunting quotas. However, long-term data size body condition Bay, well harvest from Baffin make it clear that those two at least are likely to be declining, not increasing. While ecological details vary regions occupied five different discussed this paper, analysis passive-microwave satellite imagery beginning late 1970s indicates is breaking up dates, so must fast longer periods season. Thus, part explanation appearance coastal communities camps they searching alternative food sources years when their stored fat depots may depleted before freeze-up, can return hunt seals again. We hypothesize that, if climate continues warm projected Intergovernmental Panel Change (IPCC), then all paper will increasingly food-stressed, numbers decline eventually, probably significantly so. As these decline, problem interactions between humans continue, possibly increase, seek sources. Taken together, suggest precautionary approach taken harvesting potential effects incorporated into planning management conservation species throughout Arctic.