Studying foraging behavior in marine mammals is especially difficult. Unlike terrestrial animals, which can often be directly observed, marine mammals feed underwater and across vast, remote areas, making it challenging to determine where and what they eat. Most diet studies rely on stomach contents of stranded animals, making it impossible to know where or when feeding occurred. In the Arctic, however, where Inuit communities hunt marine mammals as part of a subsistence lifestyle, this limitation can be overcome. By comparing hunted locations with the stomach contents of harvested animals, researchers can determine where and what marine mammals had been feeding.
In a recent study led by Project Assistant Professor Monica Ogawa from the National Institute of Polar Research, Japan, researchers collaborated with Inuit hunters around Inglefield Bredning (Kangerlussuaq), Greenland, to investigate spatial differences in the diet of ringed seals in relation to capture locations. The findings were published in Communications Earth & Environment journal on February xx, 2026.
“Stomach content analysis is one of the most classical methods for studying animal diets. However, because stomach contents reflect only very recent feeding—within just a few hours for seals—this approach has often been seen as a limitation. We turned this limitation into an advantage by comparing what seals had eaten with where they were captured, allowing us to investigate recent feeding activity in specific locations. This approach offers a new way to understand the feeding behavior of marine mammals,” says Dr. Ogawa.
The findings revealed not only the importance of glacier fronts as feeding grounds for seals, but also that diet varies with distance from the glacier, indicating that the loss of these habitats could have wider consequences for Arctic marine ecosystems. As Arctic glaciers continue to retreat, many tidewater glaciers are shrinking back onto land, eliminating the upwelling processes that create these feeding hotspots. The researchers warn that the disappearance of glacier-front foraging grounds could force seals to change their diet, distribution, and body condition, which in turn would affect their predators, both animals, such as polar bears, and Inuit communities that rely on seals.
“This study was made possible through the cooperation of many Inuit hunters . By working together with Inuit communities, we could obtain data—both in quality and quantity—that scientists alone could never achieve. And above all, this collaboration made the research truly enjoyable,” says Dr. Ogawa.
About Project Assistant Professor Monica Ogawa from National Institute of Polar Research, Japan
Dr. Monica Ogawa is a project Assistant Professor at the National Institute of Polar Research, Japan. Her research focuses on the ecology of marine mammals, with a particular emphasis on collaborative research with Inuit communities in the Arctic. She has been felicitated with the Young Researcher Excellence Award, ArCS II, and multiple Best Presentation awards. Her work has been featured in prominent media programs, including NHK Frontiers (Scientists and Indigenous People: The Truth About the Arctic) and NHK Science ZERO (Exploring the Frontline of Climate Change in the Arctic with Indigenous Peoples).
Funding information
This study was supported by Arctic Challenge for Sustainability II (JPMXD1420318865), funded by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT) and Arctic Challenge for Sustainability 3 (JPMXD 1720251001), JST SPRING (JPMJSP2119), funded by the Japan Science and Technology Agency, the project Eqalugaq funded by the Environmental Support Program of the Danish Environmental Protection Agency (2021–63857).
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About National Institute of Polar Research (NIPR)
The NIPR engages in comprehensive research via observation stations in Arctic and Antarctica. As a member of the Research Organization of Information and Systems (ROIS), the NIPR provides researchers throughout Japan with infrastructure support for Arctic and Antarctic observations, plans and implements Japan's Antarctic observation projects, and conducts Arctic researches of various scientific fields such as the atmosphere, ice sheets, the ecosystem, the upper atmosphere, the aurora and the Earth's magnetic field. In addition to the research projects, the NIPR also organizes the Japanese Antarctic Research Expedition and manages samples and data obtained during such expeditions and projects. As a core institution in researches of the polar regions, the NIPR also offers graduate students with a global perspective on originality through its doctoral program. For more information about the NIPR, please visit: https://www.nipr.ac.jp/english/
About the Research Organization of Information and Systems (ROIS)
ROIS is a parent organization of four national institutes (National Institute of Polar Research, National Institute of Informatics, the Institute of Statistical Mathematics and National Institute of Genetics) and the Joint Support-Center for Data Science Research. It is ROIS's mission to promote integrated, cutting-edge research that goes beyond the barriers of these institutions, in addition to facilitating their research activities, as members of inter-university research institutes.
Communications Earth & Environment
Observational study
Animals
Tidewater glacier fronts are an important foraging ground for an Arctic marine predato