Of the many sharks that roam our oceans, only a few enter the Polar regions; of these, only the Greenland shark is known to permanently inhabit the Arctic Sea. Found across the North Atlantic, from northern Europe to Canada, this shark feeds at great depths (down 2000 feet or more) for most of the year, ascending to shallower water during the winter months.
Rivaling the size of a Great White, the Greenland shark has long been hunted for its liver oil and meat; however, the latter harbors a neurotoxin and must be boiled several times and then dried before eating. Human hunters, noticing its rather docile nature during capture, inspired the common title of "sleeper shark" for this largest member of the dogfish family. Nevertheless, it appears to be capable of catching agile fish, belugas, narwhals and seals; it has also been known to feed on polar bears and caribou, perhaps nabbing them as they cross open water. Of special interest is the susceptibility of these sharks to parasitic copepods, which attach to their corneas; past theories that these parasites aided the shark by attracting prey have not been confirmed.
So, if you're dreading two more months of winter and have begun to feel sorry for yourself, just think of the Greenland shark. You could be swimming in the cold, dark waters of the North Atlantic, with a copepod attached to each eye!
