By the time she finally comes out of the den, a mother polar bear has fasted for up to five to six months. She must immediately find food to replenish herself and to feed her hungry cubs. The Beaufort Sea is among the deepest and coldest ocean bodies on Earth. However, the areas directly over the outer continental shelf, which stretches underwater off the North Coast of Alaska, and also the juncture at which the continental shelf drops off into the deep ocean, support relatively abundant marine life. Upwelling stirs water and plankton from the lower reaches of the ocean to the surface levels.
Plankton are microscopic marine organisms and are the building blocks of the marine food chain.
These microorganisms are food for many fish species which, in turn, provide food for a wide diversity of other Arctic species including marine birds, seals, and walruses. On top of the ice, and on top of the food chain, sit these hungry polar bears. Oil Tanker Mapping Dens Even in the remote Arctic habitat, polar bears face a number of dangers including increased construction of roads, refineries, and port facilities. Scientists question whether increased development related to oil production in Alaska's North Coast areas will impact polar bears. Once the five polar bears carrying satellite collars have moved into their dens, he will fly over the area of these dens in a plane carrying an infrared sensor.