By Holly Shiels, University of Manchester
The Greenland shark was one of the lesser-known species of sharks up until last year when their extreme longevity was uncovered. The finding that they live in the deep, dark Arctic waters for hundreds of years captured the imagination of the world and the attention of scientists. How does an animal born in Shakespeare’s time still patrol the deep today? What do they eat? When do they breed? What features distinguish males from females?
There are many open questions about these enigmatic animals. The purpose of our #GreenlandSharkProject expedition was to use physiology – the science of how living things work – to help us find answers.
The Greenland shark is listed by the International Union for Conservation of Nature (IUCN) as data-deficient and near-threatened. While we know the species is under pressure to survive, we need more information about its biology to form an effective conservation plan.
To gather this information, John Fleng Steffensen, Professor in Fish Physiology at the University of Copenhagen, brought together an international group of eight physiologists. Our team included experts in swimming and locomotion (kinematics), skeletal muscle and cardiac muscle, osmoregulation (the regulation of water, salt and other ions in the body) and eco-physiology (how an organism’s body adapts to its environment).
In the broadest sense, our mission was to gather data on the physiology of these mysterious animals – their hearts, their movements, their diet, and their reproduction. We were also interested in whether their body’s adaptation to cold water is related to their longevity. Clarifying how the Greenland sharks age without developing diseases associated with human ageing, like cancer and heart disease, could lead to new therapies down the line. Not only can we find clues about aging and disease, but also, understanding shark physiology is important for their conservation.
1,856 miles from Manchester to Nuuk
Before boarding the ocean-going research vessel to spend two weeks off the coast of southern Greenland, we gather in Nuuk, Greenland’s capital. The journey from Manchester to the world’s largest Island proves to be an adventure in itself.
After a hectic day in the lab in Manchester, I head to the airport for my flight to Copenhagen. I’m travelling light: a hoodie, woolen socks and the rest of the bag filled with electronics, glassware, and chemicals to make up the 15 kilograms I’m allowed to carry. A few weeks ago, I sent three large boxes of equipment and clothes to be put on a cargo ship to Nuuk.
Fast forward to a few hours later. I’ve reached my hotel in Copenhagen and head out on the town for some Danish beer with three of the other scientists, as our flight to Nuuk isn’t until the morning. Drinking now is important, as the research vessel is dry. Too much heavy equipment on the rough sea to have alcohol blurring judgement!
When I arrive back to my hotel room, I remember that I’ll need to keep my scientific chemicals cool during the night. There’s no fridge in my room, so out the window suspended on a string they go. It’s about 5 degrees Celsius outside so they should be fine, as long as there are no mischievous Danish squirrels about.
By the morning, two more team members have arrived. The five of us board our Greenland Air flight to Kangerlussuaq, Greenland. The plan is to connect there on a small plane to Nuuk, where we will join the rest of the team. The weather, however, has different plans. A large and unseasonal snowstorm is brewing above Nuuk.
Our small Dash-8 tries to find a clearing in the snow that will let us land. After circling and circling, we attempt a landing twice but the wind and snow are fierce. The pilot has no other choice but to abort. The altimeter shows that one of our landing attempts brings us just 110 metres above the runway! Finally, the captain comes over the radio with the bad news that we need to head back to Kangerlussuaq. We are running out of fuel and there was no sign of the storm lifting. This is a problem, as our ship is meant to be leaving Nuuk that night.
Luckily, the storm eventually lets up and we are able to join the rest of the team at the ship. In the end, our departure is pushed back to the next morning because of a radar issue. This gives us a final restful night at the dock before the adventure at sea!
Follow #SharkDiary on Twitter to see all the updates about the expedition.
This expedition was made possible by funding from the Danish Centre for Marine Research, the Greenland Institute of Natural Resources, The Danish Natural Science Research Council and the Carlsberg Foundation.