He may not be keen to take the plunge. The salt water is -2°C after all. Pups start with a doggy paddle. Mum stays reassuringly close. Still developing his insulating blubber, a pup is at risk of hypothermia, so needs to rest and warm up. Each day he puts on another two kilos… and practices swimming for just a little longer. Since birth, this pup has tripled in weight… and he’s now at ease in this curious other world. 12 days gone by… a mother’s work is done. Surviving on his fat reserves as his downy fleece is replaced by a sleek coat more suited to swimming. But temperatures in the Arctic are now rising faster than ever before. Creating storms that break up the ice floes earlier each spring. Harp seal pups are being tipped into freezing waters before they’re ready to endure long periods at sea. In some pupping areas, almost none survive.