A Greenland shark under the ice
In the family of Somniosidae, sleeper sharks, the Greenland shark stands out as a bit of a bad ass. It lives farther north than any other shark, is the most poisonous and has been known to eat moose!
The Greenland shark has a very extreme habitat, living in sub-Arctic waters. The water temperature ranges from just above freezing to 10°C and the sharks can even be found at depths of 2,200 meters. Because the shark is an ectotherm, in these cold waters, typical swimming speed is only between 1 and 3.5 kilometers per hour.
One of the most amazing things to learn about the Greenland shark is its diet. Besides the fish that is considered normal for sharks, remains of polar bears,cetaceans, dogs, horses, moose and reindeer have been found in their stomachs. The shark is attracted by the smell of rotting meat in the water, and after finding the carcass they will scavenge on it. They are also thought to search out and attack sleeping seals.
Greenland shark flesh contains trimethylamine oxide, which acts as a natura antifreeze. After digestion it breaks down into the neurotoxin trimethylamine will cause effects similar to extreme drunkenness. Because of this, Innuit call someone who is drunk ‘shark-sick’.
At present research is being done on Greenland sharks using DNA samples to understand the relationships between the different populations in the St. Lawrence River and Saguenay Fjord in Canada, as well as populations in Alaska and Iceland. This research is conducted by Georgina Pendell in collaboration with the Greenland Shark and Elasmobranch Education and Research Group (GEERG) and the University of Portsmouth.
Text: Dorien Schröder, Dutch Shark Society
See a Greenland shark swim:
More info:
http://www.cbc.ca/news/canada/newfoundland-labrador/moose-eating-shark-rescued-in-newfoundland-harbour-1.2434102
http://www.sharktrust.org/en/factsheets/50/greenland-shark.html
http://www.geerg.ca/gshark_1.html
