Half a dozen beluga whales dive and reemerge around tourist paddle boards in Canada's Hudson Bay, a handful of about 55,000 of the creatures that migrate from the Arctic to the bay's more temperate waters each summer. The estuaries that flow into the bay in northern Canada offer a sanctuary for the small white whales to give birth in relative warm and shelter. But the decrease in ice due to climate change, in an area that is warming three to four times faster than the rest of the planet, is a cause for concern for researchers. "When we're talking about an ice-dependent species, and belugas are an Arctic species, we have to be very worried about global warming," says Valeria Vergara, who has been studying belugas for years. IMAGES AND SOUNDBITES