The Greenland shark (Somniosus microcephalus), the second largest carnivorous shark in the world, is also considered to be one of the most mysterious shark species.
They are an elusive creature that inhabits the North American waters around Canada, Greenland and Iceland. The first underwater photograph of this species wasn’t taken until 1995.
Weighing up to 1,200 kilograms and 7 meters long, the Greenland shark lives in very cold water (-0.6°C to 10°C) and can be found at ocean depths of 2,200 meters.
Greenland sharks also have highly toxic skin. High levels of trimethylamine oxide (TMAO), an ammonia-like compound built up in the flesh and acts as a natural antifreeze. To those that eat the shark meat, the TMAO degrades to trymethylamine (TMA), a compound that can cause intestinal and neurological effects, convulsions and death.
Many questions about the Greenland shark currently remain unanswered. In a July article by the CBC, Veterinarian and Marine Biologist Dr. Chris Harvey-Clark likened studying the shark to researching mythical creatures. “How many are there? Where do they go? What do they eat? How do they reproduce? Where do they reproduce? Where are their babies? All those questions are unanswered and I think one of the fascinating things and studying the species is that it’s really been like studying Bigfoot or the yeti or an unknown animal because there’s virtually no data on it.”
In the past, the Greenland shark had been threatened due to hunting events, as they were valued for their oil rich liver that was used in oil lamps. Today, this species is at risk from trawl fisheries as they are caught as unintended catch, termed bycatch. Because their flesh is toxic, these fish are discarded once caught.
According to a 2010 paper by Dalhousie University researchers Aurelie Godin and Boris Worm (PDF), “bycatch rates of Greenland sharks in Canadian waters are significant, and have to be taken seriously given the very low productivity and poor resilience to exploitation.”
The International Union for Conservation of Nature (IUCN) have listed the Greenland shark as ‘Near Threatened’ on the basis of “possible population declines and limiting life history characteristics.” However, given the lack of information available on the species life history, and the overall negative public perception of sharks, this listing and future impacts to this particular species are not likely to change.
This poses a troubling dilemma: In a world where we have enough issues trying to defend species we seem to know everything about, how can we protect a species, that is feared, and of which we know nothing?
Shark Week has become more that just one of the longest running television events of the summer. It has also become a venue for education and the advancement of knowledge of these sometimes misinterpreted species. The Greenland Shark and Elasmobranch Education and Research Group (GEERG) is one organization that contributes to the advancement of shark knowledge to “promote shark awareness, conservation, and sustainable fishing."
This research group strongly believes that “when dealing with [an] ancient and deep-rooted issue, the best approach will always be research and education”. I couldn’t agree more. Knowledge of some of the most intriguing predators in the world’s oceans is vital for conserving the Greenland shark and those species within their shared ecosystem.