Because they grow at such a snail's pace, Greenland sharks take an extraordinarily long time to reach physical maturity. According to the 2016 study, female Greenland sharks do not attain sexual maturity until they reach a length of at least 400 centimeters (about 13 feet)—an anatomical milestone that requires roughly 150 years of continuous growth ($\text{ScienceDaily, 2016}$). This means a female shark spends a century and a half simply growing into her reproductive years, a vulnerability that makes the species exceptionally sensitive to ecological disruptions and human interference.
The Apex Predator of the Frozen Deep
Despite their slow, almost meditative movements, Greenland sharks are formidable apex predators. Growing up to 21 feet (6.4 meters) in length and weighing over a metric ton, they sit securely at the top of the Arctic marine food web ($\text{Mongabay, 2016}$).
Their dietary habits are as opportunistic as they are bizarre. Stomach content analyses over the years have revealed a startling array of prey, ranging from fast-swimming seals, squid, and fish to scavenged remains of land mammals like reindeer and horses that happened to fall into the water. In fact, many Greenland sharks are found carrying specialized parasitic copepods (Ommatokoita elongata) attached directly to their corneas. These parasites eat away at the shark's eye tissues, rendering most individuals partially or completely blind—yet this sensory handicap matters little in the pitch-black depths where smell, electroreception, and vibration dictate survival.
Conservation in a Changing Ocean
The revelation that the world's longest-lived vertebrates walk (or rather, swim) a razor-thin ecological tightrope has sparked intense discussions within international marine conservation circles. Because Greenland sharks reproduce so late in life, any accidental mortality—such as becoming entangled as commercial bycatch in fisheries targeting cod, halibut, or redfish—deals a catastrophic blow to population replacement rates ($\text{Arctic Hub, 2023}$).