A Threat to Hokkaido's Marine Ecosystem
not only is the coverage area of drift ice in the Sea of Okhotsk shrinking, but its thickness has also decreased by 30% over the past three decades.
The study, presented at an international scientific conference in the United States, analyzed data from the southern part of the Sea of Okhotsk. It found that the average thickness of drift ice has fallen from 73 cm in 1990 to just 51 cm in 2020, a decrease of 7.4 cm per decade.
This thinning ice poses a significant threat to Hokkaido's marine ecosystem. Drift ice plays a crucial role in providing iron, a vital nutrient for phytoplankton growth. The iron, originating from the Amur River in Siberia, is released into the ocean as the ice melts in spring, triggering a phytoplankton bloom that sustains the entire marine food chain, including fish.
The researchers predict that if the current trend continues, there could be years in the future when no drift ice reaches Hokkaido's coast. This would have a devastating impact on the region's fisheries and marine resources, potentially diminishing the fertility of the Sea of Okhotsk and even affecting the Oyashio current in the Pacific.
The study highlights the urgency of addressing climate change and its impact on our planet's delicate ecosystems. Protecting the drift ice and the marine life it sustains requires immediate action to reduce greenhouse gas emissions and mitigate the effects of global warming.