Narwhal Oceanographers

Today is Earth Day 2007. According to the Earth Day Network Web site, the focus of this year’s Earth Day is “A Call for Action on Climate Change”.  Climate change is a topic that is in the news a lot lately, but one rarely finds a connection between climate change and dolphins. However, there is one species of cetacean that is on the front lines of this battle against climate change: the narwhal. You might remember from a previous episode of The Dolphin Pod that we discussed a hypothesis that the narwhal’s tusk may function as a kind of barometer – sensitive to changes in the atmosphere. But, this time it’s not the narwhal’s tusk that is helping researchers learn more about climate change, it’s the narwhals themselves. Scientists are using narwhals tagged with satellite transmitters and instruments that sample water temperatures to learn more about remote regions of the Atlantic Ocean. Narwhals have been recruited as oceanographers and climate change specialists.

Kristin Laidre is a (human) oceanographer at the Polar Science Center in the Applied Physics Laboratory at the University of Washington who has been in the news thanks to her work with the narwhal tagging program. Working together with scientists from the Greenland Institute of Natural Resources, Kristin and her colleagues have been studying the waters around Greenland, in an area known as Baffin Bay. Baffin Bay is located to the west of Greenland, between the Atlantic and the Arctic oceans. Water temperatures in Baffin Bay are affected by the Gulf Stream – a powerful ocean current channel bringing warm water to the North Atlantic from waters farther south. The Gulf Stream is what keeps Europe warm enough to sustain life – if you remember the Hollywood blockbuster The Day After Tomorrow, it was changes in the Gulf Stream that brought about sudden and violent changes to the climate in the Northern Hemisphere, killing millions of people. Although scientists don’t expect anything as drastic as this to happen in real life anytime soon, climatologists and oceanographers are very concerned about the Gulf Stream. And, Baffin Bay is perhaps the first place where any changes to the Stream will be noticed, and therefore an important part of the ocean to study.

Unfortunately, scientists know very little about the real ocean temperatures in the waters of Baffin Bay. The Bay is normally covered in sea ice in the winter, making travel by ship all but impossible. Before narwhals were recruited to lend a hand, scientists had to make educated guesses as to the actual water temperature. Nobody really knew what was happening in the Bay, especially at depth. Scientists made worrisome observations just 3 or 4 years ago that the sea ice was expanding, but in the past 2 years, the trend has reversed itself and the sea ice is actually retreating at an alarming rate. Scientists suspect that climate change may be responsible and that changes in the temperatures of the Gulf Stream may be warming the waters in this part of the Atlantic.

Narwhals were chosen as optimal helpers for research in Baffin Bay because, unlike humans, they have access to all of the waters of Baffin Bay. They can dive down to a mile deep and explore areas of the Bay that are impenetrable to humans. They can make holes in the ice to breath if necessary. The narwhals used in the Baffin Bay study were captured by Kristin and her team using nets. Once the animals are trapped, the scientists fitted them with the satellite and temperature tag. The tags, attached to the animals’ backs, are capable of logging and transmitting temperature samples – as many as 400 a day – back to the researchers. Three narwhals were tagged last summer and they have been providing researchers with data all through the winter. Thanks to the narwhals, scientists are getting temperature readings from many areas of Baffin Bay, including readings at a variety of depths.
The results of the study have not yet been published. But, these narwhal oceanographers will likely have made an important contribution to the study of climate change.

Read an article from Discovery News on narwhal oceanographers Narwhals Aid Climate Change Study article