Retreating pack ice may also be helping them. A team of researchers has also been monitoring the local polar bears from a helicopter. They tranquillise, weigh and tag the animals. George Durner, from the Alaska Biological Science Center, says he has never seen the bears look in such good shape. The lengthening of the ice-free period may actually increase the amount of sunlight entering the ocean, triggering greater plant growth, plankton growth.
Fish eat the plankton.
Seals eat the fish, and polar bears feed on the seals. Feeding opportunities Scientists here are tracking the whales' movement under the ice with special microphones. Further out where the sea ice is beginning to break up, another team is counting the whales as they come up to breathe. Craig George, one of the team leaders, says the bowhead whale population is now increasing by three percent a year, after being hunted almost to extinction. He, too, says less ice may be helping them.