Excerpt from this story from EcoWatch:
The Arctic is a vast expanse of blue and white that holds still in perpetual hushed simplicity. This frozen universe, mostly undisturbed by humans for thousands of years, has retained the pristine quietness of Earth when it was born. After millennia of natural protection by virtue of its extreme climate, the Arctic has the majesty of still peaks, remote places where humans rarely go. Its grandeur is illustrated by the creatures who have been protected for so long from our tumultuous and destructive wake.
As the Arctic becomes more habitable due to global warming, it also becomes more vulnerable. The region has been invaded by equipment to conduct seismic surveys and blasts from mining operations, not to mention cruise ships, and with them new sounds have been introduced — foreign sounds in a pristine world. And for some creatures, sound is everything.
At the depths narwhals hunt — up to 1800 meters, or nearly 6,000 feet — there isn’t any light, so sound is very important to them. They navigate by echolocation like bats, by emitting click sounds. From far away, the hammering of human activity may sound like a soft “puh,” like dropping a bag of grain, but to narwhals these sounds are the equivalent of being inside a loud, clanging bell; completely disorienting.
One of many mystical creatures in this region, narwhals (Monodon monoceros) have a long tusk that has led them to be referred to by some as the unicorns of the sea. Their tusk is actually a large tooth with as many as ten million nerve endings inside and can grow as long as ten feet, according to the World Wildlife Fund. The tusk may be used as a sensory organ for the detection of everything from temperature to water pressure and motion, according to the Exchange for Local Observations and Knowledge of the Arctic. It is also flexible and can move about a foot in all directions.
A group of researchers has conducted experiments with narwhals showing that the stress response is so extreme to sounds even many miles away that it can cause them to stop feeding. The research was published in a paper, “Narwhals react to ship noise and airgun pulses embedded in background noise,” in the journal Biology Letters.
“The narwhals’ reactions indicate that they are frightened and stressed. They stop emitting the click sounds that they need to feed, they stop diving deep and they swim close to shore, a behavior that they usually only display when feeling threatened by killer whales. This behavior means that they have no chance of finding food for as long as the noise persists,” explained one of the study’s researchers, Outi Tervo, a marine biologist with the Greenland Institute of Natural Resources, Phys.org reported.