Abrupt stream acidification and metal mobilization from permafrost degradation

• 成果类型: Article
• 署名作者: Skierszkan, Elliott K.; Szeitz, Andras J.; Lindsay, Matthew B. J.; Carey, Sean K.
• 署名单位: Carleton University; University of Saskatchewan; McMaster University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aea2898
• 发表日期: 2026-05-21
• 页码: 863-867
• 关键词: mine; drainage; cycle

摘要

Stream chemistry and ecosystem function are being transformed by abrupt acceleration of sulfide-mineral oxidation in permafrost-underlain headwater catchments of the Yukon and Mackenzie river basins-the two largest (sub)Arctic rivers in North America. Over the past decade, dozens of acidic (pH similar to 3) seepages have emerged in these headwaters, causing vegetation dieback and mobilizing metals at acutely toxic concentrations in receiving streams. Acid generated during sulfide-mineral oxidation also accelerates carbon dioxide emissions by driving carbonate-mineral dissolution. Downstream (sub)Arctic rivers show statistically significant multidecadal increases in sulfate concentrations, yet their metal concentrations remain stable because of attenuation and dilution processes. Headwater stream acidification signals a major perturbation in metal, carbon, and sulfur cycling linked to permafrost thaw with far-reaching consequences for water resources, northern communities, ecosystem health, and Earth's biogeochemical future.