The average shark lives 20-30 years. Greenland sharks, however, are no ordinary predators. Scientists estimate that these giants of the sea have lifespans of at least 250 years, with some roaming the world’s oceans for upwards of 500 years.
Residing deep in the Arctic and North Atlantic oceans, Greenland sharks grow up to 24 feet in length. And like other sharks, the apex predator’s main food source is fish. Unlike others of its kind, however, Greenland sharks aren’t swift and agile hunters.
As their fastest cruising speed doesn’t even reach 2 mph, the Greenland feasts on sleeping prey rather than chasing down their meals. Their murky grey hue allows them to blend in with their surroundings, making their sneak attacks even more effective.
Unfortunately, they’re not only slow-moving but slow to reproduce as well, making overfishing a serious issue for the virtually ageless sharks. They mature at such a slow rate, in fact, that scientists believe they don’t reproduce until they’re 150 years old!
In September, the Northwest Atlantic Fisheries Organization (NAFO) met to discuss the fate of these fascinating carnivores. And after years of denying protection, NAFO finally prohibited the intentional catching and/or retention of Greenland sharks in international waters.
“It was a long time coming, but not a long time in the life of a Greenland shark,” Sonja Fordham, president of Washington, D.C.-based Shark Advocates International told Mongabay. “We were glad that it finally went through, and it’s the first for that kind of protection for NAFO.”
Scientists Hope New Protections Will Lead to Greater Research Into Greenland Sharks
With the new protections, Greenland shark fishing is prohibited. Additionally, if a Greenland shark is caught as a by-catch, it now must be released back into the water.
Scientists expect the latter portion of the rule to be most effective in preserving Greenland shark populations, as they tend to get caught by bottom trawling gear. By minimizing the risk of accidental shark deaths, scientists will have greater opportunities for research.
“There’s still so much we don’t know about them: how many there are, their abundance, their population structure,” explained Brynn Devine, marine conservationist. “We have no idea where they go to mate, or where they go to have their pups. We don’t know how many pups they have or how often they reproduce.”
“And that makes conservation planning particularly challenging,” she continued. “Because those are the things that you need to know to understand how at risk a species is to things like bycatch.”
Researchers also believe that most fishermen who pull a Greenland shark from the water in a by-catch assume they’re dead. Because they don’t attempt to escape the net, the fishermen don’t bother releasing them. What they don’t realize is that the Greenland shark isn’t dead at all, just a little lazy.
“They’re good at playing dead,” said Sonja Fordham. “So they’re often assumed dead and may not be treated particularly carefully to get them out of the net. And it can also be hard to get them out of the net.”