International consensus principles for the sustainable harvest of polar bears.

Multilateral agreements are required for the effective management of large carnivores with ranges that cross geopolitical boundaries. This is particularly important for species subject to rapid changes in distribution or demographic status due to climate warming. We considered 3 international consensus principles for the sustainable harvest of polar bears (Ursus maritimus), a circumpolar species threatened by sea-ice loss and harvested by Indigenous Peoples for subsistence. First, we defined a biologically sustainable harvest as one that occurs at a rate likely to maintain subpopulation abundance above maximum net productivity level. Second, we determined the type of scientific assessment needed to identify a sustainable harvest, which includes synthesizing or collecting information on habitat conditions, spatial population structure, and human-caused removals and conducting a field study to estimate ecological indices or demographic parameters. Third, we delineated the components of a sustainable harvest management regime, which include implementing harvest at a biologically sustainable rate, having the ability to monitor and adjust harvest levels, and following a state-dependent management approach. The consensus principles are supported by the 5 nations with polar bears (Canada, Greenland, Norway, Russia, and the United States) under an international treaty. They are designed to provide consistent guidance while allowing different jurisdictions the flexibility to tailor harvest strategies to their situations. Adapting similar principles to other systems could help mitigate the global conservation crisis for large carnivores.