Scientists have turned to narwhals to gather critical data on ocean temperatures and ice melt beneath the thick sea ice of Greenland’s eastern coast. Between 2017 and 2019, researchers working alongside local hunters from the town of Ittoqqortoormiit equipped six narwhals from the Scoresby Sound region—the world's largest fjord system—with electronic sensors. These devices have provided valuable measurements from depths exceeding 1,500 meters, an area difficult for humans to access directly.

Narwhals inhabit some of the planet’s most extreme marine environments, including the near-freezing, ice-covered waters of the Arctic. By attaching sensors to the animals, scientists have been able to track temperature and salinity variations as the narwhals follow their natural migration patterns through the fjord system. This approach offers a unique glimpse into the interplay between water layers beneath the sea ice on Greenland’s coast.

The region’s oceanography is characterized by a complex layering of water masses. Warmer, salty Atlantic intermediate water, which can reach temperatures up to 3°C, lies deep below at several hundred meters. Above it, closer to the surface, is a layer of colder polar water, typically around -2°C, created primarily from meltwater of sea ice and the Greenland ice sheet. Due to its lower salinity and density, this polar water floats atop the warmer ocean layer beneath.

Collecting direct data from these deep, ice-covered waters poses significant challenges. The presence of thick sea ice, icebergs, and strong currents limits human access and renders even advanced research vessels costly and complicated to deploy. By contrast, narwhals can navigate these conditions seamlessly, making them effective biological platforms for collecting precise oceanographic information in real time.

The data obtained is expected to enhance climate models by improving scientists’ understanding of the melting processes in Greenland’s glaciers and ice sheets. As these massive ice masses melt, they release substantial volumes of freshwater into the surrounding ocean. This influx modifies ocean circulation patterns, which are integral to regulating climate systems well beyond the Arctic.

Researchers believe that leveraging narwhals as natural sensors could revolutionize the way climate data is collected in remote polar regions, supporting more accurate predictions of future environmental changes linked to global warming.