Threats

===__How does global warming impact the planet?__ Global warming effects the planet by melting the polar ice caps. Since the polar ice caps are melting the polar bears are dieing because polar bears live on ice and they can't swim for very long. If the polar ice caps keep melting flordia well be under water. === ===Loss of Arctic snow pack and the thinning, disappearance and moving offshore of the sea-ice pack all reduce essential polar bear habitats. Loss of sea ice leads to higher energy requirements to locate prey and a shortage of food. This causes higher mortality among cubs and reduction in size among first year cubs and adult males. Another major threat is human-caused mortality. Some bears are attracted by unsecured garbage and animal carcasses. This can eventually lead to conflicts between people and bears and lethal removal of the bear. Illegal killing (poaching) of bears also remains another factor causing their decline. http://www.defenders.org/wildlife_and_habitat/wildlife/polar_bear.php===

> http://archive.greenpeace.org/climate/arctic99/reports/bearfact.html
 * Human caused deaths: bears have died from: eating a car battery, eating dye used to mark an airstrip near Prudhoe, toxic effects of ingesting oil after trying to lick fur clean, being shot when approaching oil rigs -- ie: during a 5 year study in Canada, 4 bears were shot to death 33 bears were killed over a 10 year period at oil and military installations in the Northwest Territories, a bear was shot in 1990 in Camden Bay while approaching a rig.
 * Go get BP: In 1985, Fish and Wildlife noted that seismic support traffic along the Arctic Refuge coast near Camden Bay caused a female bear to abandon her den.

Dangers to polar bears
Adult polar bears have no natural enemies, but that doesn't mean that they are safe. Boars will sometimes kill another male when competing for a mate. If cubs don't stay close to their mother, http://www.geocities.com/mikepolarbear/dangers.html?20077#|boars may also kill them. The ice is always moving and changing which can be very dangerous, especially to young cubs. A fall on the ice can injure the cub, or break a bone, which means it can't keep up with its mother. If a cub can't stay with its mother, it will probably die. || This bear has two scars across his nose from a fight with another bear || Young polar bears that are away from their mothers for the first time and still learning to hunt may not be able to find enough food or larger polar bears may steal their food. As the world gets warmer, the ice melts sooner, which means the polar bear has to stop hunting sooner and doesn't put on enough fat to survive until next winter. || Polar bears can get sick just like any other animal. They can sometimes get a worm living in them called Trichenella (trik-en-el-ah), which they get from eating seals. This worm can harm their muscles, and if the worm is close to the heart, the bear can die. || The Inuit have been hunting polar bears for thousands of years, and were a natural part of the http://www.geocities.com/mikepolarbear/dangers.html?20077#|environment. The Inuit used the polar bears for food, clothing, and bedding. In modern times people were killing many polar bears by using snowmobiles, boats, and airplanes to catch up to them, and guns to shoot them. Although hunting is restricted or banned in all countries, hunting is still a large cause of polar bear death. || Chemicals, such as PCBs and DDT in the environment move along the [|food chain]. Plankton with chemicals are eaten by fish, and seals eat the fish, and then polar bears eat the seals. The chemicals move along with the animals from plankton to fish to seal to polar bear. The chemicals can make the animals sick. The World Wildlife Fund has more information on [|risks to polar bears].
 * **Getting hurt - Ouch!**
 * **Being hungry**
 * **Getting sick**
 * **Look out! Hunters!**
 * **Pollution**

Polar bears are among the largest carnivores in the world, rivaled only by the Kodiak brown bears of southern Alaska. As its scientific name, //Ursusmaritimus//, suggests, the polar bear is primarily a marine bear. Numerous adaptations uniquely suit them to life in icy habitats. Their fur is thicker than any other bears’ and covers even their feet, for warmth and traction on ice. Polar bears can swim as far as 40 miles. The long neck and narrow skull of the polar bear probably aid in streamlining the animal in the water,and the front feet are large, flat and oarlike. A thick layer of blubber provides buoyancy and insulation.

Polar Bear Habitat and Diet
Highly dependent on pack ice in the arctic region, polar bears spend much of their time hundreds of miles from land. Polar bears travel great distances in search of prey, which consists mainly of ringed seals and bearded seals.The most important habitats for polar bears are the edges of pack ice, where currents and wind interact with the ice, forming a continually melting and refreezing matrix of ice patches. These are the areas of greatest seal abundance and accessibility. Individual bears can travel thousands of miles per year following the seasonal advance and retreat of sea ice.In one study, a single radio-collared animal ranged over an area encompassing most of the north coast of Alaska—nearly 200,000 square miles. Polar bears can also swim as far as 40 miles. ==Polar Bear Population in Decline== The World Conservation Union (IUCN) estimates that there are between 20,000 and 25,000 polar bears in the world, distributed throughout the Arctic region in 19 subpopulations of 100 to 3,000 bears each. Many of these populations are difficult to track accurately, but the trends in well-studied populations are alarming. In the western Hudson Bay, numbers have declined from 1,200 bears in 1987 to 935 bears in 2004. And in the Beaufort Sea north of Alaska, the population dropped 15 percent in five years, from 1,800 to 1,526 bears.Only the populations of the islands of Canada’s Nunavut territory are stable or increasing. In May 2006, the IUCN added the polar bear to its Red List of the world’s most imperiled animals, predicting a 30 percent reduction in the polar bear population in the next 45 years. ==Threats to Polar Bears== **Pollution:** Prevailing winds and water currents deposit residues of PCBs, pesticides and other persistent toxins in the Arctic region. Pollutants are stored in the animals’ fat and accumulate,so top predators such as polar bears receive doses sufficient to interfere with reproduction, growth and development, and immune function.**Tourism:** Tourism can lead to bear kills,particularly where poor handling of food and garbage invites bears to get used to human presence and the access to food.**Oil Exploration:** Oil exploration in prime polar bear habitats could cause pregnant females to avoid potential den sites, and spills pose a danger to bears and their prey.**Climate Change:** The most serious emerging threat to polar bears, however, is climate change. Polar bears face the loss of their sea-ice feeding and denning grounds as the Arctic climate rapidly warm.Polar bears are among the largest carnivores in the world, rivaled only by the Kodiak brown bears of southern Alaska. As its scientific name, //Ursusmaritimus//, suggests, the polar bear is primarily a marine bear. Numerous adaptations uniquely suit them to life in icy habitats. Their fur is thicker than any other bears’ and covers even their feet, for warmth and traction on ice. Polar bears can swim as far as 40 miles. The long neck and narrow skull of the polar bear probably aid in streamlining the animal in the water,and the front feet are large, flat and oarlike. A thick layer of blubber provides buoyancy and insulation.

Polar Bear Habitat and Diet
Highly dependent on pack ice in the arctic region, polar bears spend much of their time hundreds of miles from land. Polar bears travel great distances in search of prey, which consists mainly of ringed seals and bearded seals.The most important habitats for polar bears are the edges of pack ice, where currents and wind interact with the ice, forming a continually melting and refreezing matrix of ice patches. These are the areas of greatest seal abundance and accessibility. Individual bears can travel thousands of miles per year following the seasonal advance and retreat of sea ice.In one study, a single radio-collared animal ranged over an area encompassing most of the north coast of Alaska—nearly 200,000 square miles. Polar bears can also swim as far as 40 miles. ==Polar Bear Population in Decline== The World Conservation Union (IUCN) estimates that there are between 20,000 and 25,000 polar bears in the world, distributed throughout the Arctic region in 19 subpopulations of 100 to 3,000 bears each. Many of these populations are difficult to track accurately, but the trends in well-studied populations are alarming. In the western Hudson Bay, numbers have declined from 1,200 bears in 1987 to 935 bears in 2004. And in the Beaufort Sea north of Alaska, the population dropped 15 percent in five years, from 1,800 to 1,526 bears.Only the populations of the islands of Canada’s Nunavut territory are stable or increasing. In May 2006, the IUCN added the polar bear to its Red List of the world’s most imperiled animals, predicting a 30 percent reduction in the polar bear population in the next 45 years. ==Threats to Polar Bears== **Pollution:** Prevailing winds and water currents deposit residues of PCBs, pesticides and other persistent toxins in the Arctic region. Pollutants are stored in the animals’ fat and accumulate,so top predators such as polar bears receive doses sufficient to interfere with reproduction, growth and development, and immune function.**Tourism:** Tourism can lead to bear kills,particularly where poor handling of food and garbage invites bears to get used to human presence and the access to food.**Oil Exploration:** Oil exploration in prime polar bear habitats could cause pregnant females to avoid potential den sites, and spills pose a danger to bears and their prey.**Climate Change:** The most serious emerging threat to polar bears, however, is climate change. Polar bears face the loss of their sea-ice feeding and denning grounds as the Arctic climate rapidly warm. ||