In waters where ships cannot safely operate, six unlikely explorers recorded a warning hidden beneath Greenland’s winter ice.

Narwhals, known as “unicorns of the sea” because of their long spiral tusks, helped researchers study the waters of East Greenland, which are nearly inaccessible in winter. As part of a three-year monitoring effort conducted from 2017 to 2020, six animals were fitted with satellite transmitters.

As stated by CNN

Each device weighed less than 0.45 kilograms and recorded seawater temperature and salinity. The collected measurements were transmitted via satellite. Thanks to the narwhals’ ability to dive to nearly 1,830 meters, scientists obtained more than 2,000 measurements in East Greenland’s fjord system – the largest in the world.

Warm Atlantic water is reaching Greenland’s glaciers

The data obtained were compared with records from the World Ocean Database. The analysis showed an intensification of Atlantification – the intrusion of relatively warm, salty water from the Atlantic Ocean into Arctic seas and fjords.

In some areas, warm Atlantic waters penetrated more than 290 kilometers into the fjord system and reached glacier fronts. This poses a danger because the water can erode glaciers from below, accelerating ice loss.

The findings are deeply concerning, as they point to the rapid melting of marine-terminating glaciers.

– Eric Achterberg

Narwhals collected data in conditions inaccessible to ships

Accelerated melting of marine glaciers could increase risks to the Greenland Ice Sheet. Winter measurements are particularly valuable, as research vessels cannot operate safely amid unstable and unpredictable ice.

Mads Peter Heide-Jørgensen emphasized that the transmitters on the narwhals made it possible to collect information precisely during this period. Helen Coxall noted that over three years, the animals collected nearly as much oceanographic data as humans had obtained in the region over the previous 130 years.

The study showed that narwhals can be important allies in monitoring climate change in the Arctic and assessing threats to East Greenland’s glaciers.