Researchers used satellite-tagged narwhals to collect data on ocean conditions along the coast of East Greenland, according to a study published on September 1, 2026. Six narwhals were fitted with transmitters and tracked for three years as they traveled through the world's largest fjord system and dived to depths of nearly 6,000 feet. The animals provided more than 2,000 observations of water temperature and salinity, a figure marine micropaleontology professor Helen Coxall noted is comparable to the amount of data collected by humans in the region over the last 130 years.
The research was conducted because East Greenland is difficult and expensive for humans to study. Mads Peter Heide-Jørgensen, a professor at the Greenland Institute of Natural Resources and study author, stated that sending ships is dangerous due to unpredictable ice, requiring expensive icebreakers. Unlike ships, narwhals can navigate these icy waters year-round and in total darkness, allowing for repeated sampling of the entire water column. The narwhals were captured by hunters using nets before being fitted with instruments weighing less than one pound, which researchers said did not harm the animals.
The data collected revealed a process termed "Atlantification," where relatively warm and salty water from the Atlantic Ocean is pushing into Arctic fjords. In some instances, this warmer water reached more than 180 miles into the fjord system, flowing directly to the front of glaciers. Researchers found a long-term trend of this water melting the undersides of marine-terminating glaciers, which accelerates ice loss from the Greenland Ice Sheet. Eric Achterberg, a professor at the GEOMAR Helmholtz Centre for Ocean Research Kiel, described the findings as evidence of rapid melting of the marine-terminating glaciers.
The scale of the reported change involves the melting of major glaciers that drain the Greenland Ice Sheet into the North Atlantic. While the study did not provide a specific dollar figure for the damage, the data confirms that Atlantic water is penetrating 180 miles inland, affecting ice structures that regulate global sea levels. For residents in coastal areas, these changes could eventually translate to higher flood risks and altered local weather patterns as the ocean's circulation patterns shift.
The study sets a precedent for using marine mammals to gather winter data in regions where ships cannot operate. These findings will be integrated with the World Ocean Database to improve climate modeling. While the specific dates for future policy changes were not reported, Heide-Jørgensen noted that this research is one piece of a larger effort to understand the North Atlantic. Scientists will continue to monitor the region to determine the speed at which these glaciers are retreating and how it influences the broader AMOC system.