Rapidly warming oceans have left many northern marine mammals swimming in troubled waters. But perhaps none more so than that strange and mysterious "unicorn of the sea," the narwhal.
by Larry Powell Narwhals are cetaceans, a family of marine mammals which includes whales and dolphins. Most are found in Canada's Baffin Bay and Davis Strait, in the high Arctic and Atlantic Arctic. Others live off Greenland, Norway and Russia. Many spend several months over winter, beneath the ice-pack, feeding on fish, squid and shrimp and their summers in more open water. It's believed they're capable of diving as deep as 15 hundred meters and holding their breath for an astonishing 25 minutes! A pod "breaches" through an opening in the sea-ice. A US Fish & Wildlife Service photo. They can weigh up to two thousand kilograms and reach a length of about five meters. They're much larger than some dolphin species, but tiny compared to the mighty blue whale. Many migrate along the ice's edge some 17 hundred kilometres from Canada to Russia. The males grow long, spiral tusks - actually overgrown teeth - that can protrude up t