A lot less than you might think. Even the Polar bear doesn't live at the actual pole. Their food - Seals - don't live there because the ice is too thick to nibble breathing holes. Whales avoid the pack-ice as they need to come up for air. That leaves the fish and invertebrates in the sea.
With the global warming, life at the North Pole is bound to change and indeed, even now the ice is half the thickness it used to be. Pretty soon normal ships will be able to actually sail over the North Pole.