Zhu Tianyi, Zhao Shibin, Xu Bochao, Liu Dongyan, Cardenas M Bayani, Yu Huaming, Zhang Yan, Chen Xiaogang, Xiao Kai, Yi Lixin, Cho Hyung-Mi, Liu Sumei, Zhang Ziliang, Lian Ergang, Burnett William C, Chen Guangquan, Yu Zhigang, Santos Isaac R
Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, P. R. China.
Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, 266100, P. R. China.
Nat Commun. 2025 Mar 25;16(1):2932. doi: 10.1038/s41467-025-58103-y.
Submarine groundwater discharge (SGD) is a nutrient source to coastal waters. However, most SGD estimates are restricted to a local scale and hardly distinguish contributions from fresh (FSGD) and recirculated (RSGD) SGD. Here, we compiled data on radium/radon of groundwater (n ~ 2000) and seawater (n ~ 10,000) samples along ~18,000 km of China's coastal seas to resolve large scale FSGD and RSGD and their associated nutrient loads. Nearshore-scale FSGD ( ~ 3.56 × 10 m d) was only 2% of the total SGD but comparable to RSGD in terms of nutrient loads. Despite large uncertainties quantified via Monte Carlo simulations, SGD was a dominant contributor to China's coastal nutrient budgets, with dissolved inorganic nitrogen, phosphorus and silicate fluxes of ~395, 2.9, and 581 Gmol a, respectively. Total SGD accounted for 19-54% of nutrient inputs, exceeding inputs from atmospheric deposition and rivers. Overall, SGD helps sustaining primary production along one of the most human-impacted marginal seas on Earth.
海底地下水排泄（SGD）是沿海水域的一种营养源。然而，大多数SGD估算仅限于局部尺度，几乎无法区分来自淡水（FSGD）和再循环（RSGD）的SGD贡献。在此，我们汇总了中国沿海约18000公里海域沿线地下水（n≈2000）和海水（n≈10000）样本的镭/氡数据，以解析大规模的FSGD和RSGD及其相关的营养负荷。近岸尺度的FSGD（约3.56×10立方米/天）仅占总SGD的2%，但在营养负荷方面与RSGD相当。尽管通过蒙特卡罗模拟量化存在很大不确定性，但SGD是中国沿海营养预算的主要贡献者，溶解无机氮、磷和硅酸盐通量分别约为395、2.9和581 Gmol/年。总SGD占营养输入的19%-54%，超过了大气沉降和河流的输入。总体而言，SGD有助于维持地球上受人类影响最严重的边缘海之一的初级生产。
