Scientists and researchers yesterday set out on a mission to uncover the secrets of the rare Greenland Shark. A representative told the public:
"The purpose of the mission is to understand more about the Greenland shark, a top predator in the Arctic, which lives for more than 272 years -- possibly more than 400, "This extreme age was only revealed by scientists from Copenhagen last year. Little else is known about how the shark survives in the deep seas around the Arctic Circle,"
The Greenland Shark is native to the cold, deep water of the North Atlantic and extremely elusive.
The Shark grows tremendously slow, less than half an inch (a centimetre) per year, suggesting a life span well beyond those of other vertebrates. The study concluded that the shark reaches sexual maturity by the ripe age of 150 years old. Pretty good for an old’ shark.
Knowing exactly how old the shark is tricky. Unlike their bony fishy brethren that can be aged via analysis of their otoliths or ear stones, sharks, due to their excess cartilage are more difficult to determine age.
UNEXPECTED SHARK GIVES EXPLORER SHOCK OF HIS LIFE A National Geographic researcher is startled to see a Greenland shark where none has ever been seen before—off Russia's Franz Josef Land.
Greenland Sharks have a unique eye lens that grows continually throughout the Shark’s lifetime. As the Shark gets older, more and more layers are added to the lens. Unlike dating trees, scientists can’t count the rings but can remove each layer of the lens until they reach the embryonic nucleus. Similar to the 200-year-old rare Bowhead Whales that are also aged via their lenses.
Image: A Greenland was shark accidentally caught as bycatch on a research vessel in southwestern Greenland.
PHOTOGRAPH BY JULIUS NIELSEN
The tissue surrounding and inside the eye of the Shark is composed of proteins that accumulated when the Shark was born. The chemical composition of the eye lens nucleus is studied and analysed for an estimate of the shark’s age.
Why the Sharks live as long as they do is unknown. Some have speculated that it could have to do with cold water climate the shark lives in slows down their metabolism creating less damage to the animal’s tissue.
Due to the elusive nature of the Greenland Shark, nobody knows exactly how many Greenland Sharks there are left in the world. So every result is crucial.
“The longevity is remarkable, but I hope the public recognises how important that is with regard to how we manage and conserve Arctic and deep water ecosystems,” says Aaron Fisk, an ecologist at the University of Windsor who was not involved with this research.
The expedition that set out yesterday hopes to demystify the giant creature, in an effort to protect the species from becoming endangered:
"This expedition is one of the first to try and understand the physiology of Greenland sharks. With the expertise we have on the ship, we're confident that we can find out more about what makes this fish such an amazing creature"