The ancient Greenland shark revealed its age in a weird underwater video.

Greenland sharks are one of the largest marine species in the world, with a length of more than 6 meters. However, these fish prefer the deep sea and cold water in the Arctic Ocean and the North Atlantic Ocean, but they are largely unable to conduct scientific research.

Their avoidance highlights how little we know about the Arctic marine ecosystem and what we can learn by developing and adopting new technologies.

It may be a challenge for scientists like us to observe and monitor marine species. However, it is particularly difficult to take samples in waters covered with extreme depth and seasonal ice.

However, we recently filmed some underwater video clips of sharks in Greenland in the Canadian Arctic. These records give us a valuable understanding of their number, size and behavior, as well as their distribution in the Canadian Arctic.

These findings are the first step to narrow the knowledge gap of Greenland shark population.

We didn't catch any sharks from the water.

The lurking shark has not been discovered until now. Most of our knowledge about Greenland sharks comes from the historical records of commercial landings. Before 1960, they had been fishing for oily liver in the North Atlantic. The catch of Greenland is still limited, and this species is sometimes the by-catch of fisheries within its geographical scope.

A large Greenland female shark was observed near the Arctic Bay in Nu Loewit. (Brynn Devine), but in the North Atlantic and Arctic regions, commercial fishing has never happened in history, such as the waters of the Canadian Arctic Islands, and their complete geographical scope is still unknown.

Because they move slowly and look listless, Greenland sharks are a member of the "sleeping sharks" family. Greenland sharks are one of the top carnivores in the Arctic, although swimmers are very slow and blind due to eye parasites.

Although they mainly feed on various benthic fish buffets, there is evidence that they can catch live seals. How to catch these fast-swimming marine mammals is still a mystery to researchers.

Greenland sharks are the largest fish in the Arctic. If it weren't for their fear, they would be as long as the great white shark.

Scientists are also puzzled by their longevity and growth rate. They seem to grow very slowly, less than 1 cm per year. It is thought that they will not mature until the female grows to 4.5 meters and the male grows to 3 meters.

They also have extraordinary life spans. Scientists recently used radiocarbon dating technology on the lens of Greenland sharks' eyes and found that they can survive for more than 272 years, making this species the longest-lived vertebrate on earth.

Although these characteristics are impressive, the age and size of Greenland sharks make them more vulnerable to stress factors such as overfishing or habitat loss than other fish.

Frank camera scientists know little about Greenland sharks living in unpolluted waters in the eastern Arctic of Canada. In order to help collect information about sharks living in this area, we used squid as bait and put them into the deep water of Nu Loewit.

After two summer field seasons, we recorded more than 250 hours of high-resolution video from 3 1 location.

It is a small Greenland shark, less than 5 feet (1.5 meters) long, and was found in Scott Bay in northern baffin island. Greenland sharks have reached 80% of our deployment. We use this video to distinguish one person from another according to their unique skin marks, and researchers also use this method to identify whale sharks and great white sharks. We confirm that there are 142 sharks.

These videos also provide us with additional information about the shape of sharks, including their length and swimming speed. In some places, sharks are smaller, less than 1.5 meters long. Elsewhere, they are more than 3 meters long, but almost all sharks may be too small to breed.

Researchers are increasingly using videos to investigate marine wildlife. Bait camera investigation eliminated the adverse effect of scientific longline investigation, that is, hooked fishing. Even if sharks are released later, many sharks will be under the pressure of capture or entangled in fishing gear, resulting in death.

Most of our work is done in Tarutip Imanga (Lancaster Bay), which may become the largest marine protected area in Canada.

This area is an important feeding ground for many arctic species with ecological and Inuit cultural significance, including whales, seabirds, polar bears, seals and walruses. Our current video data shows that this area may also be important for Greenland sharks, at least in summer.

In addition, considering the importance of top predators in controlling the dynamics of high-latitude marine ecosystems, the role of Greenland sharks may be an important part of the Arctic food web.

With the rapid warming of the ocean, the shrinking coverage of Arctic sea ice, and people's growing interest in Arctic fisheries and protection, we must understand the territory of these ancient creatures.

Brynn Devine, Ph.D. candidate of Memorial University of Newfoundland, and Jonathan A.D.Fisher, research scientist of Memorial University of Newfoundland.

This article was originally published in Dialogue. Read the original. "