Narwhals Aid in Study of Climate Change

This undated photo provided by Kristin Laidre shows a pod of narwhals swimming off the coast of northern Canada. They thrive in ice-choked seas where humans can rarely venture. Biologist Kristin Laidre and her colleagues at the Polar Science Center at the UW's Applied Physics Laboratory have tagged three of the creatures with satellite transmitters that track the animals' movements and measure water temperatures in a region where researchers believe rapid warming is taking place. (AP Photo/APL/University of Washington, Kristin Laidre) (Kristin Laidre - AP)

The three narwhals that scientists are tracking now were trapped last summer. Each one transmits more than 400 temperatures and depth measurements daily.

For the second phase of the project, which just wrapped up, a physicist lowered an oceanographic instrument into the water that provides more detail than the sensors on the narwhals, including salinity.

The narwhal project is funded by the National Oceanic and Atmospheric Administration's Office of Ocean Exploration and the Greenland Institute of Natural Resources.

In addition to oceanographic data, the studies are shedding light on the narwhal's life. Laidre, for example, has observed that the whales create what look like mole hills by pushing through thin ice to create breathing holes.

The project has not addressed the question that has long vexed narwhal-watchers: What is the purpose of the tusk?

Some researchers have found millions of nerve channels on the surface of the tusk _ actually an elongated tooth _ and have concluded it must be a sensory organ used by males to detect changes in temperature or air pressure.

However, Laidre and Heide-Jrgensen point out that females lack tusks, yet live longer on average than males, leading them to believe the tusk can't be critical for survival.

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Information from: The Seattle Times, http://www.seattletimes.com