Using Narwhals to Gauge Climate Change
Emerging from icy Arctic waters, narwhals, with their unicorn-like teeth, have captured the imagination of researchers and explorers for centuries. Not only do they have that impressive six- to nine-foot tusk, but they also dive as deep as 4,500 feet and plunge below the surface as many as 24 times a day for half an hour at a time, making them the perfect species to collect ocean temperatures. And that’s exactly what they’re providing scientists, allowing researchers to draw critical conclusions about our warming seas.
A recent paper published in the Journal of Geophysical Research Oceans reports that the southern Baffin Bay, where narwhals swim in the winter, continues to heat up. The waters reached record high temperatures in 2006 and 2007, the authors found by looking at data collected by narwhals equipped with sensors that recorded ocean depth and temperatures.
“Narwhals proved to be highly efficient and cost-effective ‘biological oceanographers,’ providing wintertime data to fill gaps in our understanding of this important ocean area,” said Kristin Laidre, the lead author of the study who works at the Polar Science Center in the University of Washington’s Applied Physics Laboratory, in a press release. “Their natural behavior makes them ideal for obtaining ocean temperatures during repetitive deep vertical dives. This mission was a ‘proof-of-concept’ that narwhal-obtained data can be used to make large-scale hydrographic surveys in Baffin Bay and to extend the coverage of a historical database into the poorly sampled winter season.”
Conducing studies in the area during the winter can be akin to mission impossible because of the dense ice and inhospitable conditions, so Laidre and fellow researchers from the University of Washington and the Greenland Institute of Natural Resources tagged 14 narwhals with these sensors that transmitted information directly to a satellite whenever the whales surfaced. The devices lasted seven months before they fell off.
The changing conditions could threaten the 80,000 narwhals in existence, as we reported in the May-June, 2010 issue. “Continued warming will likely have pronounced effects on the species and ecosystem in Baffin Bay and may eventually affect sea ice coverage in the region, which in recent years has already retreated significantly,” Laidre said. “The timing of the break-up of spring sea ice is ecologically important for many marine species and is linked to primary production that forms the base of the food chain.”