Wrapped up to her waist in the water of the Greenland fjords, the young womanKristin LaidreHe tries to attach a satellite-controlled transmitter to the slippery spotted back of a narwhal that has fallen into his net. The scene brings to mind the famous tapestries ofThe lady and the unicorn. Because, like the mythological white steed, thecetaceancaptured is a shy and elusive creature; And just as the woman in the medieval play explores the five senses, Kristin wants to learn all aboutthe most unknown and elusive toothed whale of the seas. The difference is that it is an animal as real as these pages. Hishorn almost three meters long, which gave rise to the fantasy of the unicorn, is a stupendous ivory tusk twisted in a spiral shape, which has traditionally been worth hundreds of times its weight in gold.
Before Laidre, a 33-year-old marine biologist with a doctorate from the University of Washington in Seattle (USA), theMonodon monocerosit was a question mark. Much of what we now know about him is due to his ten years of research on the northern coasts of Canada and Greenland and Baffin Bay, an arm of the Arctic Ocean located between the North American country and the Danish territory, practically the only points where inhabits the narwhal. And although he has the invaluable help of a team of Inuit hunters and his colleague Mads Peter Heide-Jørgensen of the Greenland Institute of Natural Resources, he considers that he has hardly made a dent in his object of study.
? Possiblythe hardest animal to observe. It usually spends most of its time swimming out to sea and diving to great depths; it lives between the cracks in the thick layer of ocean ice, and sometimes seems to know how to hide and avoid nets. Some seasons you don’t see a single copy. Is it frustrating ?, explains Laidre to VERY INTERESTING in a telephone interview.
A blank sheet for biology
Thesea unicornit is part of that mission. ? We have focused our work, sponsored mainly by theNational Science Foundationand NASA, in understanding the relationships between this mammal and its habitat. Only in this way can we suggest ways to protect it. We’re trying to answer the big questions: How the removal of the icy layer and increasing the temperature of the water will affect you. Or new human activities, such as the exploitation of marine resources and the opening of maritime routes now that there is less ice.We want to know their ability to adapt to changes and how their prey will be affected, halibut, cod and squid of the genus Gonatus.?.
Putting transmitters on narwhals is the only way to trace their migratory routes or measure the degrees of water they frequent.. It is extremely difficult and expensive: they flee from the engines of boats and helicopters, they refuse to be cornered towards the coast – as their relatives the belugas can – and, since they are small whales, they have the gift of speed, for making it impossible to install the electronic tracking device on them with a rifle. Then you have to catch them with nets. Or better yet, turn to the wisdom of the indigenous population.
“The Inuit sneak up on their kayaks and put the transmitter on them with a harpoon. I used to try it myself, but I don’t even bother anymore. I leave the biologists on the beach and let the hunters do the work,” explains the biologist . Relate toinuitsays Laidre, it is one of the greatest joys of her job. He even learned to speak West Greenlandic and to cook his dishes, not caring that some of the towns do not have running water. In this friendly approach, the Eskimos receive hundreds of dollars of compensation as field assistants. It has to be said thatfor the natives of the Arctic, the narwhal is not an object of luxury, but of strict necessity. Traditionally they have taken advantage of every last inch of the whale, burning its oil in lamps, eating its meat and making boots and clothing with its skin. With the long tusk -which grows almost exclusively in males- they make sleds, harpoons, tent poles and handicraft figurines. But in 2004, the Danish government imposed limits on hunting and banned the sale of its ivory. “You don’t catch more than about 300 individuals a year,” says Laidre. And he adds: “That is sustainable.”
In the last decade,the biologist has successfully implanted transmitters in about 60 narwhals, which has allowed him to follow their lives online for months and even years. He has also analyzed many corpses and studied the contents of the stomachs. Their publications provide valuable information on migrations, diving characteristics, eating habits and the reactions of these fantastic creatures to their main predator, the killer whales. Laidreestimates that there could be between 70,000 and 80,000 specimens in the world, but nobody really knows. During the summer they inhabit the fjords and shallow bays of the Canadian and Greenlandic coasts that overlook Baffin Bay, where they migrate in winter. Then they concentrate in the deep waters, covered by a thick layer of ice. The researcher discovered that during the cold season the small cetacean not only mates, but also consumes huge amounts of fretans. That is, it is primed to face the summer.
On a typical winter day, narwhals continually dive to feed on the greasy flesh of fish that live on the dark seabed; It has been estimated that the population of Baffin Bay could consume 880 tonnes of halibut in a single day. When they return to the surface to breathe, they look for the small cracks that form in the winter ice and that, subjected to temperatures of -34º C, remain open for a short time. In April, the ice begins to lose consistency: it is the signal to start their two-month migration to the North, and the moment when Laidre and his team pack their bags to meet them. Highly sociable, they can be seen in groups, with their round heads stained in black and white poking out of the chinks of the ice.
But the famous tusk is undoubtedly the most fascinating feature of Monodon monoceros , a scientific name that precisely means “a tooth, a horn.” Full of dental pulp and nerve endings, in living individuals it appears covered with algae; its base is surrounded by parasites. No one knows exactly how and why the narwhal developed this solitary appendage when it appeared in the Pleistocene, half a million years ago . It has been said that it is used to pierce the ice, to string fish, to use it as a lure or to detect the salinity and temperature of the water. The American writer Herman Melville (1819-1891) joked that it was actually for opening envelopes.
Look what the longest fang I have …
Like most of the scientific community, Laidre accepts Darwin’s hypothesis inThe origin of the man. Following the English naturalist, the twisted tooth would perform a function equivalent to the mane of the lion, the feathers of the peacock or the horns of the elk: “It is auseful tool for establishing dominance hierarchies; to attract females and compete for them, “says Laidre. Males have been observed to rub their fangs gently against each other when girls are nearby.” The tooth cannot be crucial for survival because females usually do not have it. . As simple as that”.
The luck of the sea unicorns is inevitably linked to that of the ice. Fossils of them have been found far south, in Norfolk, England, as far as the icy layer extended 50,000 years ago. The solid body of water protects them from killer whales, which cannot penetrate the ice due to the size of their dorsal fins. This probably explains why narwhals almost completely lack a swimming appendage on their back. And what is even more important, recalls Laidre: under the frozen mantle they are fed up with halibut.
But this privileged access also comes at a price: Narwhals can be left with no way out. In fact, many drown that way in winter. Laidre thinks that mass deaths from suffocation could have caused thousands of years ago the low genetic diversity that narwhals present today.
Although now the danger comes more from the shortage of ice.Since 1979, the Arctic Ocean has lost an icy cover area twice the size of Alaska. One of the possible consequences is the increase in the amount of light that penetrates the sea, which would disturb the chemistry of the water. This in turn would cause redistributions in the chain of plankton and narwhal prey.
Lately,the burning issue of climate change has prompted Laidre to use narwhals as oceanographic sampling instruments. “Since these animals routinely go to great depths, it occurred to us that we could install temperature sensors on the transmitters they carry. Studies have shown that temperatures at the bottom of Baffin Bay are increasing. These data can be compared. and combined with historical information to analyze the thermal changes of the deep ocean. “
Although for now most narwhal populations appear stable, Laidre thinks that factors such as the rigidity of their migratory routes, low genetic diversity and the small number of marine species they feed on do not work in his favor. Especially in light of global warming. “We must continue to piece together the puzzle of narwhals’ relationships with their habitat to find out how environmental changes are affecting them.” And this, warns the unicorn lady, “is not something that can be understood in a couple of years.”
Angela Posada-Swafford
