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Polar Bear
Threats to Polar Bears
The burning of fossil fuels, the release of sequestered hydrocarbons into the Earth’s atmosphere, and extensive agriculture and deforestation are causing climate change, which in turn is causing the biggest threat faced by polar bears: the rapid loss of Arctic sea ice.
Since 1978, scientists have recorded a decline in late summer Arctic sea ice area of 7.7 percent per decade, as well as a decline in the perennial sea ice area of up to 9.8 percent per decade. In some places, a thinning of the Arctic sea ice of as great as 32 percent or more from the 1960s and 1970s to the 1990s has been shown. More important, ice is melting earlier in the year and reforming later as a result of climate change. Thus, the time available for bears to hunt on the ice and store up fat reserves for the summer and autumn is decreasing.
As the periods polar bears must go without food become longer, their overall body condition declines. Habitat loss due to global warming in the Arctic is by far the most important factor potentially affecting the future survival of polar bears.
Local fisherman Ole Berglund cleaning polluted water with a broon at the NordNorsk Beredskapssenter in Fiskebol, a training centre where people learn how to clean up oil and gas spills in water and along the coast. November 2005. Lofoten Islands, Nordland, Norway.
© Ronny Frimann-Zine.no/WWF
Oil and Gas Development and Transport
Oil and gas exploration, extraction and transportation in the Arctic affect polar bears in many ways from fragmenting and disturbing their habitat to introducing oil and other pollutants to their environment. Proposed offshore extraction poses the greatest threat to polar bears and their prey because it increases the risk of direct exposure to oil in the event of an oil spill. Spills in frozen or partially frozen waters are hard to detect and even harder to effectively clean. It is also possible that climate warming could lead to an open northern shipping route, which would increase the threat of a spill to the more isolated, northerly polar bear populations, such as Alaska's bears in the Chukchi Sea. Furthermore, exploration for oil and gas continues to pollute the atmosphere with carbon dioxide, which is the leading cause of global warming and the loss of the polar bear’s sea ice habitat.
There are already large oil and gas operations in the Arctic, and the industry is set to expand in the years ahead - especially offshore. Onshore Arctic oil installations are currently found in Russia, Canada and Alaska.
Increased Pollution
High levels of any persistent organic pollutants and toxic chemicals, such as heavy metals and radioactive elements, can cause long-term effects on the health and longevity of polar bears. Most pollutants found in the Arctic are transported from large rivers draining into the region and wind and ocean currents that bring pollutants from southern areas. Even though many of these pollutants are now banned in most countries, they are so persistent that they can remain in the environment for decades. Unfortunately, many of these pollutants bond tightly to fat molecules, and in a region highly dependent on fat for insulation, buoyancy and energy storage, these pollutants can have dramatic effects and are magnified the higher up in the food chain.
Seals, their preferred prey, are often contaminated with the persistent organic pollutants (POPs) that are prevalent in Arctic waters. When a polar bear eats a seal contaminated with POPs, the chemicals become concentrated in the bear’s fat and are stored in its vital organs. Bears with high levels of some POPs have low levels of vitamin A, thyroid hormones, and some antibodies, which are important for biological functions such as growth, reproduction, behavior and the ability to fight off disease.
Polar bear (Ursus maritimus) portrait. Churchill, Canada. Polar bears are threatened by climate change.
© Steve Morello/WWF-US
Illegal Harvest of Polar Bears
Although much of the traditional harvesting in local communities is sustainable, the over-hunting or harvesting of polar bears historically has been a threat to the species. This has been largely mitigated through various management practices implemented by WWF. However, in some parts of the bears' range, poaching is still a major problem.
There are an estimated 22,000 polar bears living in 20 discreet populations worldwide. Illegal hunting or over-harvesting does not affect all polar bear populations, but can be a major threat to smaller populations and in areas without established regulation or enforcement. Although actual harvest levels are unknown in some areas, an estimated 250-300 polar bears were illegally taken on Russia's Chukotka Peninsula in 2002, twice the level experienced in previous years. This increase is likely a result in changes in climate, causing early ice retreat and stranding large number of bears on land. A recent population study indicated that, even at a harvest level of 180 bears per year, there would likely be a 50 percent reduction in this population size in less than 20 years.
Hunting
The International Agreement on the Conservation of Polar Bears allows the hunting of polar bears by indigenous people using traditional methods and exercising traditional rights. We respect the rights of indigenous peoples to harvest marine mammals in a responsible manner. Most hunting is done in a sustainable manner, but overhunting is an additional stress on some polar bear populations. Currently, the hunting of polar bears by nonnative sport hunters is legal in Canada and Greenland.
Historically, hunting was the biggest challenge faced by polar bears. But according to the U.S. Geological Survey, hunting has become less of a stressor. It does remain an important factor as the sea ice retreats, because retreating ice will make once remote habitats more accessible and more bears will occupy terrestrial habitats. As harsh conditions become milder in certain areas, people will have new access to remote lands and the potential for human-bear interactions will likely increase.
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