New research reveals that teenage Greenland sharks in Denmark’s deep waters may be growing up much closer than previously thought, with the deep waters of Skagerrak serving as an important nursery ground for the elusive species.
Greenland Shark: A Mysterious Arctic Giant
The Greenland shark, one of the world’s largest predatory sharks, can live for centuries and usually resides in the cold, deep waters of the Arctic. Reaching lengths of at least 18 feet, the species is also believed to be the longest-living vertebrate on Earth. Long shrouded in mystery due to its remote habitat and elusive behavior, the Greenland shark has rarely been seen outside Arctic regions—until now. These sharks live a long time and stay hidden in cold waters.
A new international study, led by researchers from the Greenland Institute of Natural Resources and the University of Copenhagen’s Natural History Museum of Denmark, has uncovered important new information about the species’ life cycle. The research, based on catch data from more than 1,600 specimens across the North Atlantic, identifies the Skagerrak—deep waters between Denmark, Sweden, and Norway—as a significant developmental area for juvenile Greenland sharks in Denmark’s waters. The study shows young Greenland sharks grow near Denmark.
Skagerrak: A Quiet Refuge for Young Sharks
The comprehensive analysis revealed that the Skagerrak region hosts the largest proportion of young Greenland sharks, particularly individuals measuring between 35 and 80 inches long. This suggests that the area functions as a sort of “nursery” or adolescence zone for the species.
Unlike adult Greenland sharks, which are more commonly found in deeper Arctic waters, the teenagers seem to prefer the relative coastal proximity and depth of Skagerrak. The researchers describe it as a kind of aquatic daycare for these typically slow-moving animals, offering safe harbor away from predators and intense commercial fishing activities.
Birthplace of the Greenland Shark Remains a Deeper Mystery
Although the Skagerrak appears vital in the sharks’ teenage years, it is likely not where they are born. One of the major longstanding questions regarding the Greenland shark has been the exact location of its breeding grounds. Female Greenland sharks can give birth to hundreds of pups in a single pregnancy, each born at around 16 inches in length.
Despite decades of research across Greenland, Iceland, Norway, Canada, and Russia, no pregnant females or newborn specimens had ever been formally recorded in these regions. Yet, the study’s deep dive into museum collections and unpublished scientific databases yielded new observations: sightings of newborn Greenland sharks in the deepwaters of the Mid-Atlantic Ridge and the Irminger Sea, south of Iceland.
These findings strongly point to the species giving birth in remote areas of the deep ocean, far from human activity and commercial fisheries. Researchers believe these secluded regions could serve as critical birthing zones, possibly more than 6,500 feet beneath the surface.
Deep Waters, Deep Challenges
The Greenland shark is currently listed as “Vulnerable” on the International Union for Conservation of Nature’s Red List. Its slow growth and reproduction make it highly susceptible to environmental pressure and accidental capture in deep-water fishing operations for species such as halibut and cod.
Understanding its life stages and migratory routes is crucial for its protection. Denmark’s Skagerrak, the country’s deepest marine region, has now emerged as a key habitat for sharks in Denmark’s development—emphasizing the need for cross-border conservation strategies.
Historical and Recreational Evidence Support Findings
Remarkably, the study’s conclusions are also supported by over 150 years of historical data showing occasional strandings and bycatch reports of juvenile sharks in Denmark’s waters. In recent years, Swedish deep-sea anglers have also frequently caught juvenile Greenland sharks in Skagerrak, providing contemporary evidence for the species’ ongoing presence in the region.
Unlike other parts of the North Atlantic, Skagerrak stands out for its high rate of juvenile individuals and near absence of large, mature females. The biggest females—some exceeding 13 feet in length and over 100 years old—are typically observed in Arctic waters like southwestern Greenland or northern Canada.
These findings underscore the Greenland shark’s extraordinary life journey, which may take them from the deep Atlantic to coastal Scandinavian waters and back again over the course of centuries.
The full study is published in the scientific journal Ecology and Evolution.
