Scientists have registered massive death of polar bears in ocean waters new Alaska seaside. It seems like bears drown while swimming over large distance in artic water. Bears spend the majority of time on ice-floe, where they hunt and grow posterity.

Before 2004, scientists of USA mineral management usually saw polar bear, swimming far from ice-floe usually twice per year. Drowned bears were such a rear incident that they were not mentioned in reports.

Several experts think that climate changes cause decrease of ice area but doubt that the main initiator of this process is emission of hothouse gases. By forecast of several scientists, polar bears can die in next century because they have adapted to hunting from ice. If they try swimming in order to hunt on seals they will get tired and drown, say scientists.
sections: Nature & Health