Narwhals are toothed Arctic whales capable of deep dives. Scientists were able to attach sensors to the whales to record ocean depths and temperatures. Some of the narwhals dove deeper than one mile. The whales are able to swim and feed even during winter conditions in Baffin Bay near West Greenland, but scientists have more difficulty conducting their research then due to the increase in ice and harsh weather. So they hatched the plan to place sensors on the whales during winter and take measurements using a much easier method. Previously scientists had relied on long-term historical data based on averages, but not many direct measurements.
“Narwhals 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,” said Kristin Laidre from the Polar Science Center. (Source: NOAA.gov)
The new direct measurements coming from the whale-based sensors did help the scientists fill in gaps in their data. They found on average their ocean temperature measurements were almost a full degree greater than those in climatology data. Fourteen adult narwhals were tagged with the sensors which recorded date, time, depth, and temperature data. When the narwhals surfaced between sea ice to breathe, data from the sensors was transmitted to satellites. Sensors were tagged to the narwhals according to University of Washington guidelines which protect animals used in research. Each sensor collected up to seven months of data before falling off.