The polar bear is considered a marine mammal because it depends almost entirely on the Arctic sea ice platform to hunt its primary prey, the energy-rich ringed and bearded seals. The International Union for Conservation of Nature (IUCN) currently classifies the polar bear as Vulnerable, driven by a projected significant decline in global population size. Protecting this species is complicated by its vast, circumpolar range, which spans five nations, and the overriding threat posed by global climate change.
Drivers of Population Decline
The single greatest threat to polar bear survival is the loss of its sea ice habitat, which directly impacts its ability to acquire sufficient energy reserves. Rising Arctic temperatures lead to a shorter sea ice season, which reduces the amount of time bears can spend hunting seals.
Bears are forced onto land earlier in the year and must fast for extended periods, relying on stored fat reserves. This prolonged fasting negatively affects their overall energy balance, leading to a measurable reduction in body mass for both males and females. Reduced body condition directly translates into poor reproductive success, as mothers struggle to produce milk with enough caloric content for their cubs. This cycle contributes to higher mortality rates, particularly among cubs who cannot gain the necessary weight to survive their first fasting period.
Beyond habitat loss, polar bears face serious health risks from the bioaccumulation of persistent organic pollutants (POPs) and heavy metals. Due to their position at the top of the Arctic food chain, these contaminants accumulate in the bears’ fat tissue, or blubber, at high concentrations. These pollutants often originate from industrial and agricultural activities far outside the Arctic region. Exposure to these toxic substances is known to alter circulating levels of thyroid hormones and disrupt lipid metabolism.
Furthermore, the shrinking sea ice cover increases the frequency of interactions between polar bears and human settlements, leading to rising human-bear conflict. As sea ice retreats, bears spend longer periods on land, often drawn to coastal communities by the smell of anthropogenic food and waste. These encounters often result in defensive or preventative killings of the bears to ensure human safety.
Geographic Management Structure
Polar bears occupy a vast circumpolar range, and their management is structured around 19 scientifically recognized subpopulations, or Management Units. These subpopulations are distributed across the territories of five nations, collectively known as the Polar Bear Range States: Canada, the United States, Russia, Norway, and Greenland (Denmark).
Conservation and management decisions, such as setting sustainable harvest quotas, are therefore made at the subpopulation level rather than for a single global population. The status of the 19 units varies significantly; some are classified as declining, some are stable, and others remain data deficient due to the difficulty of monitoring in remote areas.
This transnational management is formalized under the 1973 Agreement on the Conservation of Polar Bears, which commits the five nations to coordinated action for the protection of the species and its habitat. The agreement established initial protections by prohibiting unregulated sport hunting and the use of aircraft for hunting.
It mandates that the Range States share research findings and coordinate their national research programs to ensure management is based on the best available science.
Active Conservation Strategies
The Polar Bear Range States work through the 1973 Agreement to develop coordinated strategies, such as the Circumpolar Action Plan (CAP) adopted in 2015. This plan outlines shared objectives, including minimizing threats, protecting essential habitat, and managing human-bear interactions.
International policy also plays a role in regulating the trade of polar bears and their parts through their listing on Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). This listing requires permits for international trade, ensuring that it does not threaten the species’ survival. The Range States work to enforce these regulations and combat illegal poaching and trafficking.
On-the-ground management focuses heavily on mitigating human-bear conflict to prevent unnecessary bear deaths. Local communities implement strategies like “bear patrols,” where trained residents monitor the area and use non-lethal deterrents such as cracker shells and flares to safely redirect bears away from towns. Community education programs also emphasize proper waste management to eliminate attractants that draw bears toward human habitation.
Research and monitoring are foundational elements that inform all conservation decisions. Scientists use advanced tools to gather crucial information:
- Satellite telemetry, which involves placing tracking collars on adult females to monitor their movements, habitat use, and denning habits across vast distances.
- Data essential for accurately estimating subpopulation sizes and understanding how bears are adapting to a changing environment.
- Health assessments.
- Novel techniques, such as collecting environmental DNA (eDNA) from pawprints in the snow, without invasive capture methods.