Abigail Adams, the wife of the second US president, was born in 1744. It is entirely possible that there are Greenland sharks still alive today that were swimming in the North Atlantic Ocean at that time.
There is no doubt that these large carnivorous sharks can live for hundreds of years. In 2016, researchers found that they can survive for at least 272 years, but can be as long as 400 years.
However, why these sharks have that kind of longevity is more of a mystery. Some theories include the shark’s slow growth rate and low metabolic rate, but research is ongoing.
Scientists hope that unlocking the secrets of how these fish age could help people live longer and healthier lives. We may not reach 400 years of age, but even extending the average human lifespan by an extra decade would be progress.
A scientist on the hunt is Ewan Camplisson. He has studied the metabolism of sharks for clues to their aging process.
“Better understanding the anatomy and adaptations of a long-lived species like the Greenland shark could allow us to improve human health,” Camplisson, a PhD student at the University of Manchester, told Business Insider.
A slow metabolism throughout life
A Greenland shark swimming in the North Atlantic Ocean. NOAA Office of Ocean Research and Exploration
Found primarily in the Arctic and North Atlantic oceans, Greenland sharks are smooth swimmers that can reach 8 to 23 feet in length and weigh up to 1.5 tons, according to National Geographic.
Predators feed on salmon, eels, seals, and even polar bears, given the opportunity. However, they are likely to go for long periods between meals. According to a 2022 study, a 493-pound fish could do well on 2 to 6 ounces of food per day.
Camplisson’s new research, which he presented at the Society for Experimental Biology’s Annual Conference earlier this month, showed that sharks’ metabolic rate may not slow as they age, which could help explain why sharks live so long
The same is not true of most animals, including humans. For example, a person’s metabolism tends to slow down in later years, which can contribute to unhealthy weight gain.
Camplisson looked at the activity of five metabolic enzymes in preserved Greenland shark muscle tissue. “In most species, you would expect as an animal ages that the activity of these enzymes changes,” he said.
“Some of these will show a reduction over time as they may begin to fail or degrade, while others will then compensate and increase activity to ensure the animal is still producing enough energy,” he added. .
In the Greenland sharks he looked at, which were estimated to be between 60 and 200 years old, he found no significant changes in enzyme activity. Of course, a Greenland shark can only be 200 years old, so the same may not be true when they reach their third or fourth century of life.
Camplisson plans to look at more enzymes to see if and how they change as the sharks age.
Aging is complicated
A Greenland shark captured around 2009. Xavier Desmier/Getty Images
There is still much work to be done before this type of research can be applied to humans.
“Aging is an incredibly complex system, and we still don’t have a definitive answer to how exactly it works,” Camplisson said.
For example, changes in metabolism are only part of aging in humans. Genetic errors, protein instability, and several other processes are among what are known as the “hallmarks of aging.” Camplisson thinks sharks have more to teach us in these areas.
“We want to look closely at some of these hallmarks to determine if the Greenland shark shows any signs of traditional aging,” he said.
While Greenland sharks’ remarkable aging process has allowed them to survive for centuries, it can also be a double-edged sword as their environment changes rapidly.
The species, which is considered “Near Threatened” by the World Conservation Union, may be too slow to adapt to changes in climate, marine pollution and other stressors, Camplisson said.