Arctic sea-ice has been retreating by up to 9% per decade and the length of time the northern seas are frozen each year shortens. The late freezes have serious implications for polar bears (Ursus maritimus), who rely on the ice in order to gain access to seals, the bears' primary food source. Without the sea-ice, the bears have little chance of capturing a seal.

During summer months, bears are often forced to land, as sea-ice melts. Consequently, they often capture few seals and by autumn are hungry and ready to get back on the ice. But later freezes mean famished bears are having to wait longer to hunt and conservationists are concerned as to how the bears will adapt to having to go without food for long periods of time.

Find out more: Polar Bears Face Up to Warmer Future (BBC News)

Photo © Welland Lau