Their tusks may plumb the secrets of ocean warming
By Barbara Krystal
Although unicorn whales are real, they may soon become as mythic as their name.
In the Middle Ages, the unicorn whale’s “horn” was touted as a magical elixir that could cure the plague and even raise the dead. Austrian Kaiser Karl the Fifth supposedly paid off his entire national debt with two narwhal tusks. During the Enlightenment, some three hundred years later, scientists refuted the miracle power of the “horn” that was prescribed by every apothecary in town.
Later theories proposed that narwhals were using their extraordinary tusks to break ice, spear fish, woo mates and defend their families.
But now, in the 21st century, scientists have discovered that the tusk of a narwhal is, in fact, an amazing sensory organ. And while it may not raise the dead, it could help protect all of us who are living today.
Sensing changes in the ocean
That’s because the tusks of these unicorn whales, with their 10 million nerve endings, can detect subtle changes in the oceans, thus opening a portal into the mysteries of our climate.
Six years ago, a team of scientists conducted a field study on a captured narwhal, fitting electrodes on her head.
Changes in salinity around her tusk, they found, were reflected in altered brain waves, which supported the new theory. The unharmed whale was then released.
Today, technology is allowing scientists to track the narwhal, the only species that live among dense ice cover for an extended period of time. They are hoping to discover how narwhals face the challenges created by climate change and its impact on sea ice in the Arctic Ocean: finding available resources, reduced fertility, and competition with invasive species, predation, and disease.
Through the work of Kristin Laidre, research scientist at the Polar Science Center, Applied Physics Lab, University of Washington, 14 narwhals were tagged and tracked with satellite-linked time and depth-temperature recorders between 2005 and 2007.
Narwhals typically make 10 to 25 dives per day – sometimes to depths more than a mile deep – helping Laidre and other researchers gather a wealth of data, perform statistical analysis, and make plausible predictions to long-term climate change.
In addition to recording ocean temperatures and light levels, the tags were also used to track the movements and behavior of narwhals and show where the whales went and what they did underwater.
What the narwhals have shown us
The results show a warming of the Arctic waters, which would have a global impact as well as a more direct impact on narwhals. That’s because if the ice is too thin it makes them vulnerable to predators. If the ice is too thick it acts as a barrier to oxygen. But if ice is just right, it allows narwhals ample room to navigate, hunt and breed.
The data gathered is crucial because it’s information that has been previously unattainable. In trying to gauge the impact of climate change, scientists had been relying on temperature estimates from the coastal areas of Greenland and Canada, a far cry from the depths of the feeding dives of the narwhals.
Laidre believes that “the results of this research [will] identify processes key to determining effects of climate change on narwhal adaptation, fitness and survival, and demonstrate that narwhals are important indicators for change in the offshore habitats in the high Arctic – a hostile and inaccessible area about which little is known and where few other species can provide similar insight.”
And because the narwhals don’t seem to make adjustments in their migrations to avoid hunters or to reach more abundant fishing grounds, they are the perfect guides to the Arctic and the understanding of climate change.
Narwhals are the only whales that winter in the dense Arctic pack ice where there is often less than 3 percent open water in the wintering grounds of the Canadian High Arctic to Greenland. They are finicky about their diet and eat only squid, cod and Greenland halibut, which may be a reason why narwhals reside in an area with such dense sea ice cover. Their mating rituals also occur in the cracks of space among thick ice in air temperatures of minus 60 degrees Fahrenheit.
By tracking narwhals, Laidre and other scientists now have access to a world that can teach us about the importance of climate change. With the narwhal as our trusted guide, scientists can continue that research, helping separate fact from fiction, reality from myth. And as these unicorn whales have shown us, climate change should be read as more than myth.