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Teenage Greenland sharks’ hangout spot revealed in new study


A grayish brown fish underwater with bluish eyes. One of several Greenland Sharks from the North Atlantic.
Scientists photographed this Greenland shark shortly after it was released from a longline. New research shows that juvenile Greenland sharks congregate in Skagerrak, a body of water between Denmark, Norway, and Sweden. Image via Julius Nielsen / University of Copenhagen.
  • Scientists found many juvenile Greenland sharks in Skagerrak, suggesting it’s a key hangout spot for young sharks.
  • The study also indicates these sharks are likely born near the Mid-Atlantic Ridge and the Irminger Sea.
  • The finding is important because Greenland sharks grow slowly, live for centuries, and are vulnerable due to accidental capture in fishing.

Where do juvenile Greenland sharks hang out?

There’s a lot we still don’t know about the enigmatic Greenland shark. While adult sharks are known to swim icy Arctic waters, no one quite knew where juvenile sharks congregated. Now scientists report a breakthrough in that mystery. They said that Skagerrak, a body of water between Denmark, Norway and Sweden, is home to a high number of juvenile Greenland sharks. And their study suggests these rare sharks are quite likely born near the Mid-Atlantic Ridge and the Irminger Sea, south of Iceland. These new results on the Greenland shark’s geographical distribution could help guide conservation efforts for this vulnerable species.

Peter Rask Møller, of the Natural History Museum of Denmark, is a co-author of the paper on this study. He said, in a statement:

We consider the deepest areas of the Skagerrak to be a potentially important feeding ground for ‘teenage Greenland sharks,’ and in fact, the study is the first to systematically examine the occurrence of Greenland sharks in the Skagerrak.

The study breathes new life into the story of the Greenland shark throughout the North Atlantic and, among other things, provides an understanding of how Denmark’s deepest sea area also plays a role in the species’ life history.

The scientists published their findings in the peer-reviewed journal Ecology and Evolution on June 29, 2025.

A medium-sized grayish fish in the water. On the left is a man in a boat looking at it.
Researchers caught and released this small Greenland shark, measuring about 4 feet (120 centimeters) in Vågsfjorden in northern Norway. Scientists attached a tag to it so they can study changes to the shark if it is ever re-caught. Image via Martin Nielsen / University of Copenhagen.

More about juvenile Greenland sharks in Skagerrak

The researchers were able to identify Skagerrak as a teenage Greenland shark hangout site from three decades worth of data. They extracted information from past marine surveys, scientific literature accounts and reports from anglers.

Specifically, they studied the sizes, dates of sightings and locations of 1,610 Greenland sharks in the North Atlantic Ocean. The data revealed a high number of juvenile sharks in Skagerrak, measuring between 35 inches (90 cm) and 79 inches (200 cm). Moreover, adult sharks were rare in that location.

Their findings were also supported by about 150 years of historical Greenland shark stranding and bycatch observations from Denmark. In addition, there were newer reports from recreational fisherman who had caught juvenile sharks in the deep waters of Skagerrak.

A map showing Skagerrak, the North Atlantic waters bordering Denmark, Norway, and Sweden.
A map of Skagerrak, in the North Atlantic. Image via Attilios / Wikimedia Commons (CC BY-SA 3.0)

Adult Greenland shark populations in the North Atlantic

The study did not just reveal new details about juvenile Greenland sharks in Skagerrak. The researchers also learned about the distribution of adult sharks. For instance, they found that males and subadult females were typically found in cold Arctic waters.

Large adult females, measuring over 13 feet (4 meters) long and over 100 years old, were often found in Subarctic areas, where there is warmer Atlantic water. In particular, waters off southwest Greenland, Iceland and southern Arctic Canada had the largest female Greenland sharks.

There’s still more to learn about the distribution of these sharks, and there could be other juvenile hotspots yet to be discovered.

Front half of a large grey fish in the water with a red boat in the background.
This 8-foot (2.5 meter) Greenland shark in Uummannaq, northwest Greenland, was caught and released by scientist on the research vessel RV Sanna, run by the Greenland Institute of Natural Resources. Image via Julius Nielsen / University of Copenhagen.

Where are these sharks born?

Newborn Greenland sharks measure about 16 inches (40 centimeters) at birth. Moreover, scientists think that females give birth to many pups per pregnancy, maybe 200 to 300 pups at a time.

The three decades of data covering the North Atlantic did not reveal where Greenland sharks go to give birth to live young. Therefore, the researchers turned to Danish, Norwegian and German museum collections. They also studied unpublished scientific records from Iceland, Norway and Russia. Those sources revealed observations of newborn Greenland sharks near the Mid-Atlantic Ridge and the Irminger Sea south of Iceland.

Julius Nielsen, the study’s lead author, commented:

Future targeted studies will most likely confirm that the Greenland shark gives birth to its many pups in undisturbed parts of the deep sea near the Mid-Atlantic Ridge in deep waters, where there is little activity from commercial fisheries.

Greenland sharks are mysterious deep-sea creatures

Greenland sharks (Somniosus microcephalus) live in deep remote waters of the North Atlantic and Arctic Oceans. Their watery habitat is often frigid, resulting in these cold-blooded animals having a slow-moving swimming speed. These sharks are scavengers. Also, they prey on fish such as cod and skates, as well as seals.

Their coloring ranges from pale creamy-grey to blackish brown. In addition, some have whitish spots or faint dark streaks on the back. Many Greenland sharks are infested with a crustacean called Ommatokoita elongata that hangs from its eyes.

Adults can reach 21 feet (6.4 meters) in length and weigh over 2,200 pounds (1,000 kilograms). Moreover, they are extremely long lived, the longest of any vertebrates. The oldest known Greenland shark was found to be nearly 400 years old, and scientists think they could reach a lifespan of 500 years.

Scientists also think that these slow-growing creatures reach sexual maturity at 150 years of age. The gestation period of the embryos could be 8 to 18 years long. And their young are born live.

Because of their slow growth and very long lives, scientists are concerned about the conservation of Greenland sharks. These sharks are listed as “vulnerable” in the International Red List of Threatened Species. Although there is no commercial use by humans for this shark, the biggest threat they face is being caught as bycatch in industrial fishing.

Bottom line: Scientists have discovered a high number of juvenile Greenland sharks in Skagerrak, a body of water between Denmark, Norway and Sweden.

Source: Spatial Distribution of Greenland Shark Somniosus microcephalus (Bloch & Schneider, 1801) Life Stages Across the Northern North Atlantic

Via University of Copenhagen

Read more: Sharks may be hunting other sharks

The post Teenage Greenland sharks’ hangout spot revealed in new study first appeared on EarthSky.



from EarthSky https://ift.tt/DepGl7I
A grayish brown fish underwater with bluish eyes. One of several Greenland Sharks from the North Atlantic.
Scientists photographed this Greenland shark shortly after it was released from a longline. New research shows that juvenile Greenland sharks congregate in Skagerrak, a body of water between Denmark, Norway, and Sweden. Image via Julius Nielsen / University of Copenhagen.
  • Scientists found many juvenile Greenland sharks in Skagerrak, suggesting it’s a key hangout spot for young sharks.
  • The study also indicates these sharks are likely born near the Mid-Atlantic Ridge and the Irminger Sea.
  • The finding is important because Greenland sharks grow slowly, live for centuries, and are vulnerable due to accidental capture in fishing.

Where do juvenile Greenland sharks hang out?

There’s a lot we still don’t know about the enigmatic Greenland shark. While adult sharks are known to swim icy Arctic waters, no one quite knew where juvenile sharks congregated. Now scientists report a breakthrough in that mystery. They said that Skagerrak, a body of water between Denmark, Norway and Sweden, is home to a high number of juvenile Greenland sharks. And their study suggests these rare sharks are quite likely born near the Mid-Atlantic Ridge and the Irminger Sea, south of Iceland. These new results on the Greenland shark’s geographical distribution could help guide conservation efforts for this vulnerable species.

Peter Rask Møller, of the Natural History Museum of Denmark, is a co-author of the paper on this study. He said, in a statement:

We consider the deepest areas of the Skagerrak to be a potentially important feeding ground for ‘teenage Greenland sharks,’ and in fact, the study is the first to systematically examine the occurrence of Greenland sharks in the Skagerrak.

The study breathes new life into the story of the Greenland shark throughout the North Atlantic and, among other things, provides an understanding of how Denmark’s deepest sea area also plays a role in the species’ life history.

The scientists published their findings in the peer-reviewed journal Ecology and Evolution on June 29, 2025.

A medium-sized grayish fish in the water. On the left is a man in a boat looking at it.
Researchers caught and released this small Greenland shark, measuring about 4 feet (120 centimeters) in Vågsfjorden in northern Norway. Scientists attached a tag to it so they can study changes to the shark if it is ever re-caught. Image via Martin Nielsen / University of Copenhagen.

More about juvenile Greenland sharks in Skagerrak

The researchers were able to identify Skagerrak as a teenage Greenland shark hangout site from three decades worth of data. They extracted information from past marine surveys, scientific literature accounts and reports from anglers.

Specifically, they studied the sizes, dates of sightings and locations of 1,610 Greenland sharks in the North Atlantic Ocean. The data revealed a high number of juvenile sharks in Skagerrak, measuring between 35 inches (90 cm) and 79 inches (200 cm). Moreover, adult sharks were rare in that location.

Their findings were also supported by about 150 years of historical Greenland shark stranding and bycatch observations from Denmark. In addition, there were newer reports from recreational fisherman who had caught juvenile sharks in the deep waters of Skagerrak.

A map showing Skagerrak, the North Atlantic waters bordering Denmark, Norway, and Sweden.
A map of Skagerrak, in the North Atlantic. Image via Attilios / Wikimedia Commons (CC BY-SA 3.0)

Adult Greenland shark populations in the North Atlantic

The study did not just reveal new details about juvenile Greenland sharks in Skagerrak. The researchers also learned about the distribution of adult sharks. For instance, they found that males and subadult females were typically found in cold Arctic waters.

Large adult females, measuring over 13 feet (4 meters) long and over 100 years old, were often found in Subarctic areas, where there is warmer Atlantic water. In particular, waters off southwest Greenland, Iceland and southern Arctic Canada had the largest female Greenland sharks.

There’s still more to learn about the distribution of these sharks, and there could be other juvenile hotspots yet to be discovered.

Front half of a large grey fish in the water with a red boat in the background.
This 8-foot (2.5 meter) Greenland shark in Uummannaq, northwest Greenland, was caught and released by scientist on the research vessel RV Sanna, run by the Greenland Institute of Natural Resources. Image via Julius Nielsen / University of Copenhagen.

Where are these sharks born?

Newborn Greenland sharks measure about 16 inches (40 centimeters) at birth. Moreover, scientists think that females give birth to many pups per pregnancy, maybe 200 to 300 pups at a time.

The three decades of data covering the North Atlantic did not reveal where Greenland sharks go to give birth to live young. Therefore, the researchers turned to Danish, Norwegian and German museum collections. They also studied unpublished scientific records from Iceland, Norway and Russia. Those sources revealed observations of newborn Greenland sharks near the Mid-Atlantic Ridge and the Irminger Sea south of Iceland.

Julius Nielsen, the study’s lead author, commented:

Future targeted studies will most likely confirm that the Greenland shark gives birth to its many pups in undisturbed parts of the deep sea near the Mid-Atlantic Ridge in deep waters, where there is little activity from commercial fisheries.

Greenland sharks are mysterious deep-sea creatures

Greenland sharks (Somniosus microcephalus) live in deep remote waters of the North Atlantic and Arctic Oceans. Their watery habitat is often frigid, resulting in these cold-blooded animals having a slow-moving swimming speed. These sharks are scavengers. Also, they prey on fish such as cod and skates, as well as seals.

Their coloring ranges from pale creamy-grey to blackish brown. In addition, some have whitish spots or faint dark streaks on the back. Many Greenland sharks are infested with a crustacean called Ommatokoita elongata that hangs from its eyes.

Adults can reach 21 feet (6.4 meters) in length and weigh over 2,200 pounds (1,000 kilograms). Moreover, they are extremely long lived, the longest of any vertebrates. The oldest known Greenland shark was found to be nearly 400 years old, and scientists think they could reach a lifespan of 500 years.

Scientists also think that these slow-growing creatures reach sexual maturity at 150 years of age. The gestation period of the embryos could be 8 to 18 years long. And their young are born live.

Because of their slow growth and very long lives, scientists are concerned about the conservation of Greenland sharks. These sharks are listed as “vulnerable” in the International Red List of Threatened Species. Although there is no commercial use by humans for this shark, the biggest threat they face is being caught as bycatch in industrial fishing.

Bottom line: Scientists have discovered a high number of juvenile Greenland sharks in Skagerrak, a body of water between Denmark, Norway and Sweden.

Source: Spatial Distribution of Greenland Shark Somniosus microcephalus (Bloch & Schneider, 1801) Life Stages Across the Northern North Atlantic

Via University of Copenhagen

Read more: Sharks may be hunting other sharks

The post Teenage Greenland sharks’ hangout spot revealed in new study first appeared on EarthSky.



from EarthSky https://ift.tt/DepGl7I

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