The ocean temperatures in the Arctic are about 29 F in summer. In winter the ocean temperatures can drop to 28 F, at which point seawater freezes. Hunting is the greatest single cause of polar bear mortality. Kills increased substantially in the 1950s and 1960s when hunters began using snowmobiles, boats and airplanes to hunt polar bears, but an international agreement in 1973 banned the use of aircraft or large motorized boats for polar bear hunts. Human-made toxic chemicals such as PCBs, DDT, and chlordanes are present in the Arctic and have been found in significantly high levels in the tissues of polar bears.
Starvation is the greatest threat to subadult and older, weaker polar bears.
The oldest known polar bear in the Arctic lived 32 years. The oldest known polar bear in a zoological park lived 41 years. Male polar bears have necks wider than their heads, and the collars simply fall off. Visit the Sea World Animal Resources Department . All Rights Reserved Talk Back Let us know what you think about this story in ENN's Forum Discussion Area.