Life in the open ocean is intense–warming waters, over-fishing, pollution, and competition with other animals makes surviving difficult for many species. Some tropical fish can live up to 40 years in optimal conditions, but on the other side of the ocean lives a shark that has been alive longer than the United States has been a country.

Doug Perrine Photography

The Greenland shark mainly lives in the North Atlantic Ocean and Arctic Ocean where surface temperatures stay around 28℉ (-2℃). They spend most of their time in the Midnight Zone in complete darkness but have been seen to surface during warmer months, making them a difficult species for marine scientists to study. 

Greenland sharks are vertebrates meaning they have a spinal cord like humans, though it is protected by cartilage instead of bone; fish lacking bones called elasmobranchs, and most sharks’ cartilage bodies allow for quicker swimming and efficient hunting. This isn’t the case for the Greenland shark who travels at speeds less than 2 miles per hour (3.2 km/hr) and maintains one of the slowest metabolisms in the world. They eat small amounts of food each day, are primarily considered scavengers, and have been seen to eat fish, squid, sea birds, and seals. Since they can’t move quickly, scientists suspect that Greenland sharks attack when their prey is distracted or sleeping.

They have the longest lifespan of any known vertebrate, somewhere between 270 and 500 years old. Since sharks can’t measure and share their true age with scientists, biologists resorted to analyzing eye lenses using radiocarbon dating, a process developed in the 1940s that involves measuring the amount of carbon in organic material and referencing how carbon decays over time. While human pregnancy typically lasts about 9 months, gestation in Greenland sharks lasts between 8-18 years, and once born, it takes around 150 years to reach sexual maturity. It is unknown how many Greenland sharks exist on Earth, and they have no predators.

Lars von Ritter Zahony/ Ocean Image Bank

The oldest Greenland shark was estimated to be 392 years old (±120 years), making its possible birth date between 1500 and 1740, times where the Ming dynasty still ruled over China, Spaniards arrived to the Americas, Galileo began his astronomical observations, and colonists established Jamestown in Virginia. 

Strangely, in 2013, Florida State University researchers caught a Greenland shark in the Gulf of Mexico, showing that these sharks swim long distances, migrate throughout the year, and can survive in warmer waters. Humans used to hunt Greenland sharks for their meat and communities in Iceland and the Inuit in Canada discovered its toxicity, later attributed to high levels of urea and trimethylamine oxide. Once the meat is fermented and dried, typically taking several months, it's available for human consumption and considered a delicacy in these cultures. For the Inuit, the Greenland shark inspired a legend named Skalugsuak, a poisonous sea monster. 

While there are no Greenland sharks at the Boca Aquarium, you can find bamboo sharks, leopard sharks, and more in our shark tank! We are currently expanding it from 2000 gallons to 5000 gallons, and once renovations are over, you can come check it out at 2801 N Federal Hwy, Boca Raton, FL 33431. We offer free admission and are open Mondays through Saturdays from 10am-5pm!

Have a jawsome day!

Written by Valeria Falvella