Posted: Nov 02, 2010 4:09 am
by HughMcB
Narwhals transmit climate data from Arctic seas
Marine mammals armed with thermometers return temperature readings from icy Baffin Bay.

Lucas Laursen
Published online 28 October 2010 | Nature

The cold water beneath the winter pack ice in Baffin Bay is getting warmer, according to measurements taken by thermometer-wearing narwhals1. The data collected from the diving mammals fill in a geographical and seasonal gap in the region's climate records, as no winter temperatures were previously available from the area. The data also confirm that a warming trend measured during earlier summer-only studies of the West Greenland Current continued in the three years to 2007.

"We basically knew nothing about winters up in Baffin Bay," says physical oceanographer Mike Steele at the University of Washington in Seattle, who co-authored the study, which appeared last week in the Journal of Geophysical Research1. "But there is a lot of interest in the flow of seawater around Greenland."

The idea is not new: other polar research teams have placed oceanographic instruments on marine mammals, including elephant seals, which dive around 2,000 metres below the surface in the Southern Ocean, and bearded seals, which swim up fjords in Greenland2,3,4. But this is the first time that researchers have used narwhals (Monodon monoceros) for oceanography, and it is the first such study to target Baffin Bay, a data-scarce area of some 689,000 square kilometres.

Other Arctic researchers welcome the hard-to-get data as a way of improving climate predictions. "We need more observations to check and change and fine-tune our models so I think it's brilliant to get winter-time data," says oceanographer Lars Böhme at the University of St Andrews in Scotland, who was not involved in the study.


Narwhals have been recruited to help
collect climate data in Baffin Bay.D. B.