The frigid waters of the Arctic are home to near-mythical creatures, sometimes called the "unicorns of the sea" for the long, ivory tusk that spirals several feet out of the top of their heads.

Worldwide there are only about 50,000 to 80,000 narwhals, as they are more commonly known, with about two-thirds of these whales summering in the fjords and inlets of Nunavut in northern Canada.

Scientists are hoping to learn more about narwhals through a new effort to track them as they move around the icy waters of northern Canada, as well as more about how declining amounts of sea ice are affecting the creatures.

"Although we've been working on a better understanding of the narwhal in the past seven or eight years, it was only recently that people have figured out how to fit satellite radios to them, so we know where they go and what they're eating,” said Pete Ewins, an Arctic species specialist for the environmental group WWF-Canada.

Narwhal transmitters

A new project tagged nine narwhals in Tremblay Sound off the coast of the northern province of Nunavut back in August. The scientists restrained the whales, which can weigh up to 3,500 pounds (1,600 kilograms), and fitted them with a satellite radio that has a transmitter mounted with Teflon rods to the blubber near the whale's dorsal area.

"The whole system is no bigger than a Blackberry cellphone, with a little transmitter the length of a pencil that sticks up," Ewins told OurAmazingPlanet.

When a narwhal comes to surface, the radio unit contacts with the air and activates the signal transmission. The animal's location is then sent via satellite to the researchers.

Of those nine whales fitted with the device, seven still have trackers that are transmitting information. For the others, the system likely malfunctioned or fell off. Eventually all of the trackers will be slowly expelled by the animals’ immune system.

While seven whales isn't a huge sample size, Ewins said that a lot of information can be gained by watching where the whales go. "Their position tells you depth of water over which they're spending the dark days of winter," he said.

Story continues

Preserving Arctic waters

In addition to the basic coordinates, digital sensors also record the depth and the duration of each whale's dive. From that information, scientists can infer what the whales are eating during different times of the year, and how the thickness of sea ice in different parts of the Arctic impacts their behavior. [Infographic: Tallest Mountain to Deepest Ocean Trench]

The information can also be used to make a case for keeping these northern waters free from oil and gas exploration. Since narwhals are both protected and acoustically sensitive, knowing their locations could help the government make better decisions to preserve marine environments.

"The local native Inuit, who are our partners, are concerned about the changes in the sea ice but also the prospect of noisy ships and explosions to test for oil and gas," Ewins said.

You can track the whales' movements here.

This story was provided by OurAmazingPlanet, a sister site to LiveScience.