北極域の氷河前縁は“ご馳走スポット” —アザラシの胃内容物が示す初の直接証拠—

2026-04-03 国立極地研究所,京都大学,北海道大学

図1：研究成果の概要。研究チームは、氷河からの距離ごとに捕獲したアザラシの胃内容物を分析し、氷河前縁近くの個体ほどホッキョクダラを多く摂取し、胃の内容量も多いことを確認した。

＜関連情報＞

• https://www.nipr.ac.jp/info2026/20260403.html
• https://www.nature.com/articles/s43247-025-03174-4

潮汐氷河の先端は、北極の海洋捕食動物にとって重要な採餌場である Tidewater glacier fronts are an important foraging ground for an Arctic marine predator

Monica Ogawa,Teunis Jansen,Aqqalu Rosing-Asvid,Sascha Schiøtt,Caroline Bouchard,Evgeny A. Podolskiy,Søren L. Post,Yuta Sakuragi,Mayuko Otsuki,Shin Sugiyama & Yoko Mitani

Communications Earth & Environment  Published:18 February 2026

DOI:https://doi.org/10.1038/s43247-025-03174-4

Abstract

A view that tidewater glacier fronts are important feeding grounds for marine predators is becoming widespread, although there is little direct evidence of their foraging activities and diet in these areas. Here, we conducted a spatial analysis of the stomach contents of ringed seals to investigate their diet and its relationship with glacier fronts, making the most of the unique opportunity provided by Inuit hunting, which allows obtaining stomachs with hunted locations. Our results showed that seals captured near glacier fronts consumed more prey than those captured farther away, particularly feeding on polar cod. Furthermore, the prey composition varied among capture locations, suggesting varied foraging strategies reflecting prey availability. Our study indicates that seals feed intensively at glacier fronts, emphasizing the potential for recent climate-induced glacier retreat to deprive seals of key foraging grounds, leading to changes in their behavior, diet, and habitat use.