Hokkaido University researchers have conducted a study revealing the alarming decline of drift ice thickness and coverage in the Sea of Okhotsk. Over the past 30 years, the sea ice in this area has lost 30% of its thickness, with Hokkaido's coast potentially facing a future where no ice floes reach its shores due to the effects of global warming. Scientists have observed thinner ice formations during the winter spectacle of drift ice descending on Hokkaido's northeastern coast facing the Sea of Okhotsk.
The study conducted by Professor Kay Ohshima and his team at Hokkaido University showed that drift ice in the southern Sea of Okhotsk has been thinning at a rate of 7.4 centimeters per decade. The average drift ice thickness has decreased by 30% over three decades, highlighting the rapid pace at which ice is diminishing in the region. Furthermore, projections by Professor Humio Mitsudera suggest that by 2050, the coverage area of drift ice in the southern Sea of Okhotsk could be only a fraction of what it was in previous years, showcasing the dire consequences of continuing greenhouse gas emissions.
The reduction in drift ice poses a significant threat to the marine ecosystem and fisheries in the Sea of Okhotsk. Professor Jun Nishioka emphasizes the importance of drift ice as a source of iron, essential for phytoplankton growth, which in turn supports the entire marine food chain. Less drift ice could lead to a decrease in iron supply, impacting phytoplankton proliferation and subsequently diminishing fishery resources not only in the Sea of Okhotsk but also in neighboring areas like the waters off the Sanriku coast. This cascading effect could disrupt the ecosystem and fertility of marine resources in the region.