Greenland sharks need only about 200 grams of fish per day to survive, with a lifespan of several hundred years.

By studying the metabolic rate, a team led by Eric Ste-Marie at the University of Windsor in Canada has gained valuable information about the environmental stress of Greenland sharks. In a study published in the journal Experimental Biology , Eric Ste-Marie and his colleagues examined how much food Greenland sharks need to survive from day to day.

Greenland sharks inhabit the cold waters of the North Atlantic and Arctic Oceans, as well as the waters surrounding Greenland. They are large sharks, averaging 8–15 feet (2.4–4.6 m) in length. They are one of the longest-lived animals on Earth and the longest-lived vertebrates in the world. Researchers believe they can live up to 500 years. A 2016 study in the journal Science estimated the lifespan of 28 Greenland sharks, with the longest individual being between 335 and 392 years old.

Eric Ste-Marie’s team captured 30 Greenland sharks over five years, tagging them, taking samples, and installing biosensors that collected information about their movements, body temperatures, and water temperatures. The results showed that Greenland sharks were very lethargic, moving around at very slow speeds. Using this information, the team was able to determine the Greenland shark’s caloric needs. Accordingly, an individual weighing about 227 kg needs to eat 57 – 184 grams of fish or marine mammals to survive.

This is much lower than other sharks that live in warmer waters and swim fast. A study published in 2013 estimated that a 2,000-pound great white shark would need to eat 66 pounds of fish oil every 11 days. Previous studies have found that animals with slow metabolisms live longer, while those with fast metabolisms live shorter.

In the study, the scientists stressed that understanding the feeding needs of Greenland sharks is important to determine how they will survive as climate change changes prey and food webs. Greenland shark populations are declining and their Arctic habitat is warming faster than any other region on Earth.