A group of 50 beluga whales is fighting to stay alive in an icy trap in the Canadian Arctic near Ellesmere Island.

An unexpected freeze has left dozens of the whales trapped in a sea of ice, with one small hole as their only window for air. The open sea is 20 kilometres away.

About 20 of them have already died, despite the best efforts of wildlife officials. The reason: polar bears. With the whales swarming their only air hole, they've become easy prey for the bears.

The polar bears are hunting the belugas at will. Even in the best of conditions, belugas can only spend about 10 minutes underwater. When they come up, the bears jump onto the whales and tear chunks out of them.

Unless the ice breaks up soon, the belugas' chances of survival are grim.

Beluga whales live only in the arctic and subarctic. They live in the Arctic Ocean and its adjoining seas, including the Sea of Okhotsk, the Bering Sea, the Gulf of Alaska, the Beaufort Sea, Baffin Bay, Hudson Bay, and the Gulf of St. Lawrence.

1. Whom or what has an unexpected freeze left as their only window for air?