Mu Guangli, Huang Meiqi, Wu Zhengyu, Cui Hongyang, Yang Qing, Li Xiaodong, Cui Xiaoyu, Tong Yindong
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; School of Ecology and Environment, Tibet University, Lhasa 850000, China; Key Laboratory of Biodiversity and Environment on the Qinghai-Tibet Plateau, Ministry of Education, Tibet University, Lhasa 850000, China.
J Hazard Mater. 2025 Jul 15;492:138117. doi: 10.1016/j.jhazmat.2025.138117. Epub 2025 Mar 31.
Glacier shrinkages and evolutions of post-glacial ecosystems due to human-induced climate change represent some of the most rapidly occurring ecosystem shifts with potential ecological and societal cascading consequences on Earth. Glacial meltwater could introduce a substantial amount of nutrients, dissolved organic matter (DOM), and contaminants stored in glaciers into the lakes. However, influence of glacial meltwater on microbial communities and its impacts in the transformation of trace contaminants by microbes are frequently underestimated. This study explored the distribution of nutrients, mercury (Hg), and microbial communities across the meltwaters, surface waters, deep waters, and outflows of three proglacial lakes that formed after 2000 on the Tibetan Plateau. Our results revealed that alterations in the DOM composition, particularly the efficient metabolism of carbohydrates (CHO), may foster growth and activities of microorganisms. This could enhance the abundance of potential Hg methylators, resulting in an increase in the ratio of methylmercury (MeHg) to total mercury (THg) in water. Our findings highlight substantial interaction between microbial community and compositional variabilities of DOM in proglacial lake. It underlines the essentiality of integrating these factors into future risk appraisals of aquatic ecosystems in proglacial lakes in the context of global climate changes.
