Drift ice, also known as ice floes, is a captivating natural phenomenon in Japan's northern seas, attracting tourists and supporting a rich marine ecosystem. However, Hokkaido University researchers have discovered troubling trends in the Sea of Okhotsk, where drift ice is not only shrinking in coverage area but also losing thickness at an alarming rate due to climate change.
The annual arrival of drift ice along Hokkaido’s northeastern coast, facing the Sea of Okhotsk, has been a long-standing event, with this past winter being no exception. Despite the mesmerizing sight of the sea's surface packed with massive blocks of ice, scientists have noted that the ice is thinner now than in the past. Professor Kay Ohshima's analysis, along with his colleagues, revealed a concerning thinning trend of 7.4 centimeters per decade in the southern Sea of Okhotsk, highlighting a 30% reduction in average ice thickness from 1990 to 2020.
Professor Humio Mitsudera's use of advanced climate change scenarios to predict the future of drift ice in the Sea of Okhotsk paints a grim picture, indicating a drastic decrease in ice coverage by 2050. As global warming continues, the study suggests that there could be a significant decline in drift ice, with potential implications for marine ecosystems and fisheries off the coast of Hokkaido. Jun Nishioka, a professor of chemical oceanography, warns of the consequences of diminished ice supply on marine life, especially the crucial role that iron from drift ice plays in supporting phytoplankton growth and sustaining the marine food chain in the Sea of Okhotsk.